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| #531652 (Received by flhurricane at: 11:14 PM 03.Aug.2012) AFDKEY AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS NATIONAL WEATHER SERVICE KEY WEST FL 1108 PM EDT FRI AUG 3 2012 .DISCUSSION... SCATTERED SHOWERS AND THUNDERSTORMS DROPPED SOUTH OF THE FLORIDA KEYS EARLIER THIS EVENING...LEAVING CONVECTIVELY INACTIVE OUTFLOW BOUNDARIES PUSHING WESTWARD THROUGH THE SERVICE AREA. MORE RECENTLY...A CLUSTER OF SHOWERS AND THUNDERSTORMS IS WEAKENING OVER THE UPPER KEYS AND THE SOUTH PORTION OF FLORIDA BAY. WINDS ACROSS THE SERVICE AREA HAVE TAKEN ON A MORE DECISIVE NORTHEAST DIRECTION...BUT REMAIN GENTLE AWAY FROM ANY BOUNDARIES AND WANING STORMS. THE LATE EVENING LOCAL SOUNDING CAME IN SLIGHTLY DRIER THAN 24 HOURS AGO...BUT WITH SLIGHTLY HIGHER INSTABILITY. ALSO...DEEPER MOISTURE ALONG WITH A WEAK WAVE IS RIGHT UPSTREAM FROM THE KEYS AT THIS TIME. WE CAN EXPECT SOME OF THE MOISTURE TO INCREASE ALBEIT SLOWLY THROUGH THE OVERNIGHT PERIOD. WITH MANY BOUNDARIES MOVING THROUGH...SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED THROUGH THE OVERNIGHT PERIOD. A RECENTLY UPDATED ZONE FORECAST WAS ISSUED...MAINLY TO ADJUST THE WIND DIRECTION TO THE NORTHEAST/EAST. && .MARINE... AS WITH THE ZONES...A RECENTLY UPDATED COASTAL WATERS FORECAST INITIATED THE WINDS IN ALL MARINE ZONES FROM THE NORTHEAST/EAST. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS MOVING THROUGH ALL MARINE ZONES OVERNIGHT. BUT AWAY FROM THESE STORMS...SPEEDS WILL BE AT OR AROUND 10 KNOTS TONIGHT INTO SATURDAY MORNING. && .AVIATION... REST OF TONIGHT...A TROUGH OF LOW PRESSURE EAST OF THE TERMINALS WILL ALLOW FOR REDEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS UPSTREAM OF BOTH THE KEY WEST AND MARATHON TERMINALS. SHORT LIVED MVFR/IFR OR EVEN LIFR CIGS AND/OR VIS WILL BE LIKELY WITHIN SOME OF THESE SHOWERS AND STORMS THAT MANAGE TO IMPACT THE TERMINALS. LIGHT TO GENTLE NORTHEAST WINDS WILL BECOME VARIABLE AGAIN DURING THE NIGHT AHEAD OF THE DEVELOPING CONVECTION...BUT ISOLATED WIND GUSTS NEAR 30 KNOTS ARE POSSIBLE IN SHOWERS AND THUNDERSTORMS. AMENDMENTS WILL BE ISSUED. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...NONE. GM...NONE. && $$ |
| #531651 (Received by flhurricane at: 11:12 PM 03.Aug.2012) AFDCRP AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1002 PM CDT FRI AUG 3 2012 .DISCUSSION...GOES SOUNDER IMAGERY CONTINUES TO SHOW AN INCREASE OF MOISTURE MOVING IN OVER THE WESTERN GULF THIS EVENING. MODEL SOUNDINGS CONTINUE TO SHOW PWATS TO INCREASE THROUGH SATURDAY...WITH PWATS NEARING 1.7 INCHES. WITH DECENT LAPSE RATES AND AVAILABLE CAPE...SHOWERS ARE EXPECTED TO DEVELOP TONIGHT MAINLY OVER THE GULF WATERS THROUGH SATURDAY MORNING...ALTHOUGH REMAIN VERY ISOLATED. DID START THE CONVECTION EARLIER. OTHERWISE...NO OTHER CHANGES MADE TO THE FORECAST PACKAGE. && .PREV DISCUSSION... /ISSUED 640 PM CDT FRI AUG 3 2012/ DISCUSSION...UPDATED FOR 00Z AVIATION. AVIATION...VFR CONDITIONS WILL PREVAIL AT THE TERMINALS THROUGH THE TAF CYCLES. SOUTHEAST WINDS WILL SUBSIDE AT ALI/CRP/VCT BY 02Z BUT PICK UP AND PERHAPS BE A LITTLE GUSTY AT LRD THROUGH THE EVENING. ANTICIPATE SIMILAR CONDITIONS TOMORROW AS SOUTHEAST WINDS INCREASE AS THE SEA BREEZE MOVES INLAND. THERE MAY BE ENOUGH MOISTURE ON SATURDAY TO TRIGGER ISOLATED CONVECTION ALONG THE SEA BREEZE. HOWEVER...WILL NOT MENTION IN THE TAFS ATTM DUE TO LOW CONFIDENCE IN STORMS DEVELOPING. PREV DISCUSSION... /ISSUED 245 PM CDT FRI AUG 3 2012/ SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...MID/UPPER LEVEL HIGH PRESSURE CONTINUES TO DOMINATE OUR WEATHER PATTERN THROUGH THE START OF THE WEEKEND. WILL CONTINUE WITH AN OVERALL PERSISTENT FORECAST AS AFTERNOON TEMPERATURES REACH INTO THE TRIPLE DIGITS ALONG AND WEST OF HIGHWAY 281. MOISTURE VALUES INCREASE A BIT ACROSS THE REGION OVERNIGHT INTO SATURDAY...THUS WILL MAINTAIN THE MENTION OF PRECIPITATION FOR MORNING SHOWERS OVER THE WATERS...AND SLIGHT CHANCE OF CONVECTION DURING THE AFTERNOON. HOWEVER...ANY ACTIVITY WILL BE VERY ISOLATED IN NATURE AS SUBSIDENCE REMAINS IN PLACE AND THERE IS NO MAJOR FOCUS FOR LIFT. OVERNIGHT CONDITIONS WILL CONTINUE WARM AND MUGGY THROUGH THE FORECAST PERIOD AS WELL. LONG TERM (SUNDAY THROUGH FRIDAY)...CONCUR WITH THE GFS/ECMWF THAT THE UPPER RIDGE WILL RETROGRADE TOWARD THE NW DRG THE PERIOD. THUS...SUBSIDENCE EXPECTED TO DECREASE OVER THE CWA/MSA. FURTHER... CONCUR WITH THE GFS/NAM THAT A REGION OF GREATER MSTR...CURRENTLY OVER THE CNTRL GULF...WILL ENTER THE CWF/MSA EARLY IN THE PERIOD. THE COMBINATION OF THE FOREGOING/AFTN INSTABILITY (GFS CAPE/CIN) WILL CONTRIBUTE TO AT LEAST ISOLD CONVECTION. ANTICIPATE CONVECTION TO CONTINUE DRG THE PERIOD YET WITH THE GREATEST CHANCE OVER THE ERN CWA/MSA TUESDAY-WEDNESDAY. (EXPECT CONVECTION OVER THE COASTAL WATERS TO BE PRIMARILY NOCTURAL.) EXPECT MAX TEMPS TO FALL ONLY SLIGHTLY MONDAY-WEDNESDAY OWING TO GREATER MSTR...YET AT LEAST 100-105F MAX HEAT INDEX VALUES. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 78 97 78 96 78 / 10 10 10 20 10 VICTORIA 75 95 75 96 75 / 10 20 10 30 10 LAREDO 79 104 79 103 79 / 0 10 0 10 10 ALICE 76 102 76 99 76 / 10 10 10 20 10 ROCKPORT 80 91 80 90 81 / 10 20 10 30 10 COTULLA 76 103 75 102 75 / 0 10 0 10 10 KINGSVILLE 77 100 77 99 76 / 10 10 10 20 10 NAVY CORPUS 80 91 80 89 81 / 10 10 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531649 (Received by flhurricane at: 10:48 PM 03.Aug.2012) AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 926 PM CDT FRI AUG 3 2012 .DISCUSSION... ZONE PACKAGE IS ON TARGET. && .PREV DISCUSSION... /ISSUED 620 PM CDT FRI AUG 3 2012/ AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD, HOWEVER THERE WILL BE ISOLATED TSRA AROUND THE REGION BY MID DAY SATURDAY. CB IS DISPLAYED IN TAF, HOWEVER NO VCTS DUE TO LOW COVERAGE, BUT MAY BE ADDED LATER. WINDS WILL BE LIGHT AND GENERALLY SOUTH TO SOUTHWEST. PREV DISCUSSION... /ISSUED 440 PM CDT FRI AUG 3 2012/ DISCUSSION... LATEST WATER VAPOR SATELLITE IMAGERY/UPPER AIR ANALYSIS SHOWED UPPER RIDGE CENTERED OVER CENTRAL/EASTERN TEXAS...WITH A DISCERNIBLE SHORTWAVE EVIDENT DROPPING SOUTH THROUGH CENTRAL LOUISIANA. AT THE SFC...HIGH PRESSURE RIDGES WWD FROM THE ATLANTIC ACROSS THE NORTHERN GULF OF MEXICO. LATEST RADAR IMAGERY SHOWERS ISOLATED-SCATTERED CONVECTION ONGOING ACROSS SOUTH CENTRAL/SOUTHEAST LA. HAVE KEPT THE EVENING AND OVERNIGHT FCST DRY WITH THE IDEA THAT THE LOSS OF DAYTIME HEATING SHOULD RESULT IN THIS ACTIVITY WANING...BUT WITH THE LIFT ASSOCIATED WITH THE PASSING SHORTWAVE...IT MAY CONTINUE INTO THE EVENING HOURS...AND WOULD NOT BE SURPRISED IF THE EVENING CREW HAD TO EXTEND A SMALL POP BEYOND 00Z. NO MAJOR CHANGES WERE MADE TO THE GRIDDED FORECAST THIS AFTERNOON. GLOBAL MODELS CONTINUE TO SHOW THE MID/UPPER RIDGE LIFT A BIT TO THE NORTH TOMORROW...BEFORE RETROGRADING WWD ON SUNDAY...WITH DEEPER MOISTURE WORKING ITS WAY WEST INTO THE REGION. THIS...ALONG WITH SHORTWAVE ENERGY SLIDING UNDERNEATH THE RIDGE TOMORROW...AND TRAVERSING THE REGION ON SUNDAY...WILL RESULT IN INCREASING RAIN CHANCES THROUGH THE WEEKEND. THE RIDGE IS FCST TO CONTINUE WWD AND AMPLIFY OVER THE FOUR CORNERS REGION NEXT WEEK...LEAVING THE REGION WITHIN A WEAKNESS/SHEAR AXIS BETWEEN THIS RIDGE AND THE SUBTROPICAL RIDGE TO THE EAST. OTHER THAN MONDAY AND PERHAPS INTO TUESDAY...WHEN AN INVERTED UPPER TROF IS PROGGED TO PASS TO OUR SOUTH...DID NOT SEE ANYTHING CONCRETE TO HANG MY HAT ON IN TERMS OF RAISING RAIN CHANCES ABOVE CLIMO...BUT BEING IN NW FLOW ALOFT CAN OFTEN BRING SURPRISES. REGARDING THE TROPICS...THE PROGRESS OF ERNESTO WILL OF COURSE CONTINUE TO BE MONITORED. THE LATEST OFFICIAL TRACK FROM NHC BRINGS ERNESTO TO THE YUCATAN PENINSULA AS A HURRICANE BY WEDNESDAY AFTERNOON...WITH A COORDINATED NHC/HPC TRACK CONTINUING A GENERAL NW MOTION INTO THE SW GULF ON DAYS 6 AND 7. THERE REMAINS A LARGE MODEL SPREAD IN THIS LATTER PART OF THE FORECAST...THUS RESIDENTS ARE ENCOURAGED TO KEEP UP WITH THE LATEST NHC FORECASTS. 13 MARINE... SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE ACROSS THE NORTHERN GULF OF MEXICO FROM THE WESTERN ATLANTIC. THIS WILL RESULT IN MAINLY ONSHORE FLOW AND RELATIVELY LOW SEAS THROUGH THE WEEKEND...HEADING INTO NEXT WEEK. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 80 92 77 92 76 / 10 20 10 60 20 KBPT 76 92 77 92 76 / 10 20 10 60 20 KAEX 77 96 76 94 75 / 10 20 10 50 20 KLFT 77 92 76 91 75 / 10 20 20 60 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ |
| #531648 (Received by flhurricane at: 10:48 PM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1031 PM EDT FRI AUG 3 2012 .SYNOPSIS... LARGE HIGH PRESSURE OFF THE ATLANTIC COAST WILL REMAIN STATIONARY THROUGH SATURDAY. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY... THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... PREVIOUS FORECAST MAINLY ON TRACK WITH DRY CONDITIONS EXPECTED FOR THE REST OF THE OVERNIGHT PERIOD. ALSO UPDATED TEMPS/DP FOR CURRENT TRENDS. WARM AND MUGGY CONDITIONS WILL CONTINUE OVERNIGHT WITH DEW POINTS IN THE UPPER 60S TO LOWER 70S ACROSS THE AREA AND EXPECTED TO STAY THERE THROUGH THE NIGHT. OTHERWISE...TEMPS WILL DROP SLOWLY TONIGHT...WITH MANY LOCATIONS REMAINING IN THE 70S PER MOS. MID TO UPPER 60S ACROSS THE INTERIOR. DO EXPECT PATCHY FOG AS LIGHT SOUTHERLY WINDS PERSIST AND TEMP/DEW POINT DEPRESSIONS SHRINK. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... LARGE RIDGE OVER THE WESTERN ATLANTIC AND UP THE EASTERN SEABOARD PREVAILS THIS TIME FRAME. WITH THIS RIDGE IN PLACE...LIGHT WINDS AND PLENTY OF WARM AIR ALOFT SHOULD KEEP ANY AFTERNOON/EVENING CONVECTION TO A MINIMUM. SLIGHTLY COOLER BOUNDARY LAYER WILL RESULT IN LOWER SFC/MIXED LAYER INSTABILITY AS WELL. HOWEVER...ANY SHOWER OR THUNDERSTORM THAT DOES DEVELOP WILL PULSE BRIEFLY...AND COULD BE STRONG. THE COOLER BOUNDARY LAYER IS COURTESY OF INCREASING SOUTH TO SOUTHEAST FLOW...INJECTING MARINE LAYER OVER A GOOD PORTION OF THE CWA. HOWEVER TEMPS WILL STILL BE QUITE WARM TO HOT...80S TO NEAR 90. WITH HIGH DEW POINTS REMAINING IN THE 70S...HEAT INDICES WILL ONCE AGAIN RISE INTO THE 90S. A FEW LOCATIONS IN AND AROUND NYC COULD SEE 95 DEGREE HEAT INDICES...BUT GIVEN UNCERTAINTY AND MARGINAL CONDITIONS...WILL HOLD OFF ON ANY HEAT ADVISORIES AT THIS TIME. TIME OF YEAR A FACTOR WITH SEVERAL HEAT EVENTS UNDER OUR BELT AS WELL. THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN FACING BEACHES ON SATURDAY. ON SATURDAY NIGHT...MUGGY AND WARM CONDITIONS CONTINUE WITH SOUTH FLOW PERSISTING. STRATUS AND FOG EXPECTED ONCE AGAIN. FOLLOWED A MOS BLEND CLOSELY THROUGH THIS TIME PERIOD. HARD TO BEAT MOS NUMBERS IN THIS TYPE OF STAGNANT/PERSISTENT PATTERN. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HOT AND HUMID AIRMASS IN PLACE SUNDAY AS STRONG SOUTHERLY WINDS DEVELOP DUE TO A TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRES ANCHORED OVER THE WESTERN ATLANTIC AND AN APPROACHING COLD FRONT MOVING THROUGH THE OHIO VALLEY. CONDITIONS BECOME QUITE UNSTABLE AS TEMPS CLIMB THROUGH THE 80S...AROUND 90 IN/AROUND NYC...ALONG WITH SFC DEW POINTS WELL INTO THE 70S. THIS WILL RESULT IN A HEAT INDEX CLOSE TO 100 DEGREES IN/AROUND NYC AND THE URBANIZED AREAS OF NE NJ...AND IN THE LOW TO MID 90S ELSEWHERE. STRONG SOUTHERLY FLOW...COMBINED WITH INCREASING SURF HEIGHTS... WILL LIKELY RESULT IN A HIGH RISK FOR RIP CURRENTS AT THE OCEAN BEACHES ON SUNDAY. THERE MAY BE A FEW SHOWERS/TSTMS LINGERING INTO SUNDAY MORNING AS WEAK TROUGH/SHORTWAVE MOVE THROUGH THE REGION...BUT MORE ORGANIZED ACTIVITY WILL HOLD OFF UNTIL THE AFTERNOON AND EVENING HOURS AS THE COLD FRONT OVER THE OH VALLEY MOVES INTO WESTERN NY/PA DURING THE DAY SUNDAY. PRE-FRONTAL TROUGH AHEAD OF THE COLD FRONT WILL TRACK INTO WESTERN PORTIONS OF THE FORECAST AREA BY AFTERNOON...AND THAT LOOKS TO BE A TRIGGERING MECHANISM FOR SOME RATHER STRONG TO SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING. CAPE VALUES WILL BE OVER 2000 J/KG IN SOME PARTS OF NJ AND INTO NYC...ALONG WITH A LIFTED INDEX CLOSE TO -7 C AND INCREASING LOW LEVEL WINDS. AS THIS COMPLEX COLD FRONT/UPPER TROUGH/SHORTWAVE SYSTEM MOVES INTO THE AREA SUNDAY EVENING...SHOWERS AND THUNDERSTORMS WILL INCREASE IN INTENSITY AND COVERAGE SUNDAY EVENING. THUNDERSTORMS WILL BE CAPABLE OF DAMAGING WINDS IN THE AFTERNOON...BUT WITH LOSS OF DIURNAL HEATING COMES THE LOSS OF THE THREAT FOR DAMAGING WINDS. IN ADDITION TO THE DAMAGING WIND THREAT...THERE IS ALSO THE THREAT FOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING IN THE AFTERNOON/EVENING...THEN TORRENTIAL RAINFALL SUNDAY NIGHT WILL RESULT IN THE POTENTIAL FOR FLASH FLOODING OVERNIGHT SUNDAY NIGHT INTO MONDAY MORNING. WITH PWATS RANGING FROM 2.25-2.5 INCHES...THERE IS ABUNDANT MOISTURE IN THE ATMOSPHERE TO FEED ANY THUNDERSTORMS. THINK THE MID LEVEL WINDS WILL BE TOO STRONG TO ALLOW ANY STORM TO LINGER OVER ANY ONE AREA...BUT TRAINING OF CELLS WILL LEAD TO FLASH FLOODING. PRECIPITATION TAPERS OFF FROM WEST TO EAST MONDAY MORNING AS THE FRONTAL SYSTEM TRACKS THROUGH THE REGION. THE FRONT BECOMES STATIONARY SOUTH OF LONG ISLAND LATE MONDAY THROUGH TUESDAY AS HIGH PRES BUILDS THROUGH THE REGION ON TUESDAY. HUMIDITY LEVELS WILL FALL DRASTICALLY AS DEW POINTS DROP FROM THE 70S INTO THE LOWER 60S. TUESDAY WILL END UP QUITE PLEASANT WITH LOW HUMIDITY...FAIR SKIES AND TEMPS IN THE 80S. STATIONARY FRONT SOUTH OF LONG ISLAND LIFTS BACK NORTH AS A WARM FRONT ON WEDNESDAY. ISOLATED SHOWERS/TSTMS POSSIBLE WITH ITS PASSAGE. SFC COLD FRONT WITH UPPER LEVEL SUPPORT FROM AN H5 TROUGH/SHORTWAVE COMBO THEN APPROACHES ON THURSDAY...POSSIBLY TOUCHING OFF SOME MORE SHOWERS/TSTMS. SOME CONCERNS WITH FORECAST LATE IN THE WEEK...AS HIGH PRES MOVES THROUGH THE REGION...BUT DEPENDING ON HOW FAST IT DEPARTS WILL IMPACT IF LOW PRES UPSTREAM MAKES IT TO THE LOCAL AREA OR NOT. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... A WEAK PRESSURE PATTERN REMAINS IN PLACE THROUGH THE TAF PERIOD. S-SW WINDS UNDER 10 KT THROUGH THE MORNING PUSH. VFR TO START...THEN AFTER MIDNIGHT...FOG EXPECTED TO REDUCE THE VISIBILITY...BUT THIS IS A LOW CONFIDENCE FORECAST. HIGHER CONFIDENCE THAT ANY VISIBILITY RESTRICTIONS DUE TO FOG REMAIN HIGHER THAN IFR WITH THE EXCEPTION OF KGON AND KHPN. SEVERAL TERMINALS COULD END UP WITH GREATER THAN 5SM VISIBILITY ALL NIGHT. TIMING OF FOG ALSO DIFFICULT WITH SCT-BKN CIRRUS SHIFTING THROUGH...EVENTUALLY EXITING TO THE EAST. COULD BE AN HOUR OR TWO TOO EARLY WITH THE TIMING OF FOG RESTRICTIONS IN MOST CASES. OUTLOOK FOR 00Z SUN THROUGH WED... .SAT NIGHT...ISOLD/SCT TSTMS POSSIBLE IN THE EVENING. IFR POSSIBLE AFTER MIDNIGHT. .SUN...EARLY IFR POSSIBLE. GUSTY S WINDS...MAINLY IN THE AFTERNOON. LATE DAY AND NIGHTTIME TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE/WED...VFR. && .MARINE... PERSISTENT SOUTHERLY FLOW CONTINUES OVERNIGHT AND THROUGH SATURDAY. SUB SCA CONDITIONS ARE ANTICIPATED. SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKE UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING ON SATURDAY. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH THE THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MPS/PW |
| #531646 (Received by flhurricane at: 10:47 PM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1026 PM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 10:30 PM FRIDAY...NO CHANGES TO THE GOING FORECAST. EXPECT A QUIET OVERNIGHT PERIOD. LOSS OF DAYTIME HEATING HAS LEAD TO A CESSATION OF CONVECTION FOR THE EVENING. CANNOT RULE OUT THE SPOT SHOWER INLAND OVERNIGHT...CONSIDERING RESIDUAL BOUNDARIES AND ONGOING STRONG CONVECTION OVER THE FOOTHILLS OF CENTRAL NC AND SC. HOWEVER...NO LONGER ANY UPPER SUPPORT FOR STRONG STORMS OVER OUR AREA. RADAR LOOPS SHOW SHOWERS WELL OFFSHORE GRADUALLY APPROACHING THE COAST. THESE APPEAR TO BE OUTRIDERS OF A WEAK TROPICAL WAVE EXTENDING NNE FROM THE VIRGIN ISLANDS. DO NOT EXPECT THESE WILL MAKE IT ASHORE DURING THE NEAR TERM AS THEY ARE DISSIPATING AS THEY APPROACH THE COAST. COULD SEE SOME PATCHY FOG OVERNIGHT WHERE WE HAD APPRECIABLE RAINFALL TODAY. LITTLE CHANGE IN MINIMUM TEMPERATURES FROM RECENT DAYS...EXPECT LOWER TO MID 70S MOST LOCATIONS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...AMPLIFICATION OF THE BERMUDA RIDGE WILL BRING SUBSIDENT DRYING ALOFT TO THE REGION SATURDAY...WHICH WILL LIKELY SQUELCH TSTMS INTO AN ISOLATED CATEGORY. LOW-LEVEL MOISTURE WILL LINGER ACROSS THE EASTERN CAROLINAS IN SOUTHERLY MOIST FLOW TO 700 MB. SURFACE HEATING AND THE SEA BREEZE FRONT SHOULD INTERACT WITH THIS MOISTURE TO PRODUCE ISOLATED AFTERNOON CONVECTION. IT IS NOT COMPLETELY CLEAR IF THE DRYNESS COULD RESULT ONLY IN SHRA AS OPPOSED TO TSTMS...BUT HAVE INCLUDED THUNDER DUE TO STRONG SFC HEATING. SUNDAY IS INTERESTING...IN THAT MOISTURE DEEPENS AND A WEAK TROPICAL WAVES MOVES INTO FLORIDA...ADVERTISING COASTAL SHOWERS ENCROACHING MAINLY SOUTH CAROLINA. HAVE RAISED POP VALUES SUNDAY BUT DUE TO THE UNCERTAINTY OF THE TROPICAL WAVES NORTHERN INFLUENCE...HAVE HELD POP VALUES IN THE ISOLATED TO SCATTERED CATEGORY SUNDAY. BOTH DAYS WILL BE SIMILAR IN TEMPERATURE...BUT SATURDAY COULD BE A FEW DEGREES WARMER DUE TO LESS CLOUDS AND MORE COLUMN SUBSIDENCE. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...LACK OF ANY SIGNIFICANT 5H TROUGH COMBINED WITH WEAK RIDGING AT THE SURFACE AND ALOFT WILL KEEP A WEAK COLD FRONT STALLED NORTHWEST OF THE REGION FOR MUCH OF THE PERIOD. DURING THE MIDDLE OF NEXT WEEK A SHORTWAVE TROUGH WILL REINFORCE THE 5H TROUGH...PUSHING WHAT IS LEFT OF THE STALLED BOUNDARY TO THE COAST LATE NEXT WEEK. FOR THE FIRST HALF OF THE PERIOD THE BERMUDA HIGH AND STALLED FRONT WILL PRODUCE THE TYPICAL SUMMER PATTERN WITH SEA BREEZE CONVECTION AND STALLED FRONT THE INITIAL FOCUS FOR CONVECTION. RESULTING OUTFLOW BOUNDARIES WILL GENERATE ADDITIONAL STORMS...BUT GIVEN SOME MID LEVEL SUBSIDENCE DO NOT THINK COVERAGE WILL BE ABOVE 30 TO 40...SIMILAR TO CLIMO. LATE IN THE PERIOD TROUGHING ALOFT HELPS PUSH REMAINS OF FRONT TO THE COAST. TROUGH AXIS WEST OF THE AREA LEADS TO DEEP SOUTHWEST FLOW...TAPPING GULF MOISTURE. POP REMAINS IN THE CHANCE REALM THROUGH THE END OF THE PERIOD GIVEN LOW LEVEL CONVERGENCE AND PRECIPITABLE WATER VALUES OVER 2 INCHES. TEMPERATURES WILL BE WITHIN A FEW DEGREES OF CLIMO THROUGH THE PERIOD...UPPER 80S TO LOW 90S AND LOW TO MID 70S. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... AS OF 00Z...VFR CONDITIONS EXPECTED THIS EVNG. MVFR VSBYS IN BR WILL DEVELOP 08Z-12Z AT FLO/LBT TERMINALS...WITH TEMPO MVFR VSBYS AT THE ILM TERMINAL. THERE IS ONLY MDT CONFIDENCE OF IFR VSBYS AT FLO/LBT 09-12Z. VSBYS AT CRE/MYR THE VSBYS SHOULD REMAIN VFR OVERNIGHT BUT A TEMPO MVFR CEILING IS PSBL AT ANY COASTAL TERMINALS 08-12Z. VFR EXPECTED AFTER SUNRISE. THE PROB OF THUNDERSTORMS IS LOW SAT THUS WILL NOT MENTION IN TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 10:30 PM FRIDAY...LATEST OBS SHOW SOUTHERLY WINDS OF AROUND 15 KTS WITH SEAS OF 2 TO 3 FT OVER THE WATERS. SOUTHERLY WINDS WILL CONTINUE THROUGH THE PERIOD. THE 2 TO 3 FT SEAS CURRENTLY WIDESPREAD ACROSS THE WATERS WILL REMAIN UNCHANGED THROUGH THE OVERNIGHT PERIOD. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...S-SSE WINDS EXPECTED SATURDAY AND SUNDAY...AND INCREASING A BIT INTO SUNDAY. THIS FETCH WILL BUILD SEAS FROM 2-3 FT MUCH OF SATURDAY...TO 3-4 FEET SATURDAY NIGHT INTO SUNDAY AS SSE WINDS INCREASE TO AROUND 15 KNOTS BY SATURDAY EVENING. SEAS WILL BE A MIX OF SSE WAVES WITH MIXED WAVE PERIODS OF 6 SECONDS AND 10 SECONDS. STORMS WILL BE ISOLATED SATURDAY...AND MAINLY OVER LAND. BY SUNDAY...INCREASING SHOWERS AND TSTMS OVER THE WATERS MAY BE EXPECTED AS A TROPICAL WAVE MOVES INTO NORTH FLORIDA. THIS ACTIVITY WILL BE FAVORED OVER THE SC WATERS IN CLOSER PROXIMITY TO THE WAVE. NO SMALL CRAFT ADVISORIES ARE EXPECTED THIS WEEKEND. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 3 PM FRIDAY...BERMUDA HIGH AND STALLED DISSIPATING FRONT ACROSS THE CENTRAL CAROLINAS WILL KEEP SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. EARLY ON...THE GRADIENT WILL BE ILL-DEFINED KEEPING SPEEDS ON THE LOW END OF THE 10 TO 15 KT RANGE. SLIGHT PINCHING OF THE GRADIENT LATE IN THE PERIOD WILL LEAD TO A MARGINAL INCREASE IN SPEEDS...THOUGH WINDS SHOULD REMAIN IN THE 10 TO 15 KT RANGE. SEAS WILL RANGE FROM 2 TO 3 FT FOR MUCH OF THE PERIOD WITH SOME ISOLATED 4 FT POSSIBLE WELL OFF CAPE FEAR. && .TIDES/COASTAL FLOODING... TIDAL DEPARTURES ABOUT NORMAL THIS EVENING. CONSIDERING THAT WE JUST BARELY MET COASTAL FLOOD ADVISORY CRITERIA LAST NIGHT...DO NOT THINK THAT WE WILL MEET IT THIS TIME. NO ADVISORIES PLANNED FOR THE NEAR TERM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531642 (Received by flhurricane at: 10:42 PM 03.Aug.2012) AFDSJU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1021 PM AST FRI AUG 3 2012 .UPDATE...A FLASH FLOOD WATCH HAS BEEN ISSUED FOR EASTERN PUERTO RICO FROM 2 AM SATURDAY TO 2 PM SATURDAY. CONSIDERING DIFFERENT QPF FORECASTS INCLUDING HPC AND GFS MODEL SHOW THIS AREA WITH AT LEAST 2 INCHES OF PRECIPITATION FOR THAT AREA DURING THAT TIME...AND ALSO CONSIDERING THE LOCAL HYDROLOGIC EFFECTS BASED ON THE DURATION AND INTENSITY OF EXPECTED WEATHER. IT WAS DECIDED TO ISSUE THE FLASH FLOOD WATCH FOR THAT AREA AND NOT OTHER PORTIONS OF THE ISLAND. THAT HOWEVER DOES NOT MEAN THAT THE OTHER AREAS WILL NOT RECEIVE RAIN...BUT FLASH FLOODING IS NOT ANTICIPATED FOR THOSE AREAS AT THIS TIME. A LINE OF SHOWERS WITH GUSTY WINDS MOVED ACROSS THE LOCAL ISLANDS THIS AFTERNOON AND EVENING. THE SAINT THOMAS AIRPORT REPORTED 43 MPH WIND GUST WHILE SAINT CROIX REPORTED 36 MPH WIND GUST ABOUT 2 HOURS EARLIER AND SAN JUAN REPORTED 35 MPH WIND GUST WITH THAT SAME LINE OF SHOWERS. THIS LINE HAS BEEN MOVING WESTWARD THROUGH THE EVENING HOURS. HOWEVER...RAINFALL TOTALS HAVE NOT BEEN TOO IMPRESSIVE DUE TO HOW QUICKLY THE SHOWERS ARE MOVING. THE USVI REPORTED ABOUT A TENTH TO 2 TENTHS OF RAIN AND SAN JUAN ONLY OBSERVED 0.02 INCHES OF RAIN. WEATHER AND MARINE CONDITIONS ARE EXPECTED TO CONTINUE DETERIORATING THROUGH THE NIGHT AND INTO THE MORNING HOURS. QUICK MOVING SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BECOME MORE NUMEROUS AS TIME GOES BY. BUOY 42060 IS REPORTING PERSISTENT SUSTAINED WINDS OF AT LEAST 25 KNOTS OR HIGHER WITH WAVE HEIGHTS NOW UP TO 10 FEET AND A PERIOD OF AROUND 5 SECONDS. THIS IS THE BEHAVIOR WE EXPECT FOR OUR LOCAL WATERS AS TROPICAL STORM ERNESTO CONTINUES TO MOVE RAPIDLY TO THE WEST. && .AVIATION...WIND SHIFT EXPECTED TO OCCUR SHORTLY ACROSS USVI THEN AROUND 07Z AT JSJ AND AROUND 10Z ACROSS JMZ/JBQ. EXPECT WINDS TO INCREASE CLOSE AROUND 18G30KT. CIGS WILL DROP TO MVFR AFTER 06Z AS MOISTURE DEEPENS AND SHOWERS AND THUNDERSTORMS INCREASE. SHOWERS AND THUNDERSTORMS WILL BEGIN TO EXIT THE AREA AFTER 15Z BUT CIGS WILL BE SLOW TO IMPROVE. WINDS WILL CONTINUE TO BE QUITE GUSTY FROM THE SOUTHEAST AT 15G25KT. WINDS SUBSIDE SAT NIGHT AND CIGS BECOME VFR AFTER 05/00Z. && .PREV DISCUSSION... /ISSUED 211 PM AST FRI AUG 3 2012/ SYNOPSIS...AT 2 PM AST...TROPICAL STORM ERNESTO WAS LOCATED NEAR LATITUDE 13.7 NORTH...LONGITUDE 62.3 WEST AND WAS MOVING TOWARD THE WEST AT NEAR 21 MPH. ERNESTO IS EXPECTED TO MOVE GENERALLY WEST FOR THE NEXT COUPLE OF DAYS...WITH A GRADUAL DECREASE IN FORWARD SPEED. ON THE FORECAST TRACK...ERNESTO WILL MOVE ACROSS THE EASTERN CARIBBEAN OVERNIGHT THROUGH SATURDAY...BRINGING OUTER BANDS OF MOISTURE TO THE LOCAL AREA...WITH CLOUDINESS...SHOWERS AND THUNDERSTORMS AND INCREASINGLY BREEZY TO WINDY CONDITIONS.. UPPER LEVEL HIGH PRESSURE RIDGE WILL REMAIN IN PLACE ACROSS THE NORTHEASTERN CARIBBEAN THROUGH AT LEAST SATURDAY. IT IS THEN EXPECTED TO GRADUALLY ERODE LATE SUNDAY INTO EARLY NEXT WEEK...AS TUTT AND ASSOCIATED LOW ACROSS THE CENTRAL ATLANTIC RETROGRESSES WESTWARD OVER THE REGION. SURFACE HIGH PRESSURE NORTH OF THE AREA AND TROPICAL STORM ERNESTO NOW ENTERING THE EASTERN CARIBBEAN WILL MAINTAIN AN EAST TO NORTHEAST WIND FLOW ACROSS THE REGION. THIS WILL RESULT IN THE SURFACE PRESSURE GRADIENT RAPIDLY TIGHTENING OVERNIGHT THROUGH SATURDAY. LATEST VISIBLE SATELLITE IMAGERY AND BLENDED TOTAL PRECIPITABLE WATER SHOWED THAT MID TO UPPER LEVEL MOISTURE ACROSS THE NORTHEAST HAS BEGUN TO INCREASE DURING THE AFTERNOON IN ADVANCE OF THE TROPICAL STORM. DISCUSSION...OVERALL FAIR AND STABLE WEATHER CONDITIONS DOMINATED THE LOCAL AREA TODAY AS HIGH PRESSURE RIDGING AND SUBSIDENCE IN ADVANCE OF TROPICAL STORM ERNESTO LIMITED SHOWER DEVELOPMENT. EXPECT PARTLY CLOUDY SKIES TO VARIABLY CLOUDY DURING THE EARLY EVENING WITH INCREASING CLOUDINESS AND DETERIORATING CONDITIONS LATER THIS EVENING AND OVERNIGHT THROUGH SATURDAY AS ERNESTO AND ASSOCIATED MOISTURE FIELD SPREADS ACROSS THE EASTERN CARIBBEAN. THE TIGHTENING OF THE LOCAL PRESSURE GRADIENT WILL BRING BREEZY TO LOCALLY WINDY CONDITIONS TO THE REGION. IN ADDITION...DEEP MOISTURE ALONG THE NORTH AND EAST PERIPHERY OF THE TROPICAL STORM WILL BE LIFTED UP ACROSS THE AREA...INCREASING THE CHANCES FOR ACTIVE AND INCLEMENT WEATHER CONDITIONS. BASED ON PRESENT LATEST MODEL GUIDANCE...EXPECT THESE CONDITIONS TO BEGIN DURING THE EARLY EVENING ACROSS THE NORTHERN LEEWARD AND VIRGIN ISLANDS. THEREAFTER...IT WILL PROGRESSIVELY INCREASE IN COVERAGE AND SPREAD WEST AND NORTH ACROSS PUERTO RICO AND ADJACENT ISLANDS ON SATURDAY. INFREQUENT BURSTS OF GUSTY WINDS AND LOCALLY HEAVY RAINFALL MAY OCCUR FROM TIME TO TIME OVERNIGHT ACROSS THE COASTAL WATERS AND THE COASTAL SECTIONS OF THE ISLANDS.HOWEVER... THE HEAVIEST RAINFALL IS EXPECTED EARLY SATURDAY MORNING AND CONTINUING INTO EARLY SUNDAY. DURING THAT TIME...PERIODS OF NUMEROUS SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS ALONG WITH SQUALLS ACCOMPANYING THE BANDS OF SHOWERS AND THUNDERSTORMS. AVIATION...TROPICAL STORM ERNESTO WILL CONTINUE TO MOVE SOUTH OF THE LOCAL ISLANDS THIS EVENING THROUGH SATURDAY. SOME OF THE OUTER BANDS WILL AFFECT THE VI TAF SITES LATE THIS EVENING SPREADING OVER PR TOMORROW MORNING. LLVL WINDS WILL REMAIN FROM THE NORTHEAST THRU TONIGHT...VEERING FROM THE EAST TO SOUTHEAST EARLY SATURDAY THRU SUNDAY. SFC WINDS OF 15 TO 25 KTS WITH HIGHER GUSTS UP TO 40 KTS WILL REMAIN POSSIBLE DURG THE NEXT 24-48 HRS DURG PASSAGE OF TS ERNESTO. && .PRELIMINARY POINT TEMPS/POPS... SJU 78 87 78 89 / 80 80 60 20 STT 79 88 79 91 / 50 50 30 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...FLASH FLOOD WATCH FROM 2 AM AST SATURDAY THROUGH SATURDAY AFTERNOON FOR CENTRAL INTERIOR-EASTERN INTERIOR-NORTHEAST- SOUTHEAST. VI...NONE. COASTAL WATERS... SMALL CRAFT ADVISORY UNTIL 6 AM AST SUNDAY FOR ANEGADA PASSAGE SOUTHWARD TO 17N. SMALL CRAFT ADVISORY FROM 11 AM TO NOON AST SATURDAY FOR COASTAL WATERS OF NORTHERN PUERTO RICO OUT 10 NM-COASTAL WATERS OF NORTHWESTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY UNTIL 6 AM AST SUNDAY FOR COASTAL WATERS OF SOUTHERN USVI VIEQUES AND EASTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY UNTIL NOON AST SUNDAY FOR CARIBBEAN WATERS OF PUERTO RICO FROM 10 NM TO 17N. SMALL CRAFT ADVISORY FROM 2 AM SATURDAY TO NOON AST SUNDAY FOR COASTAL WATERS OF SOUTHERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM NOON SATURDAY TO NOON AST SUNDAY FOR COASTAL WATERS OF SOUTHWESTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY UNTIL NOON AST SUNDAY FOR ATLC WATERS OF PUERTO RICO AND USVI FROM 10NM TO 19.5N-MONA PASSAGE SOUTHWARD TO 17N. SMALL CRAFT ADVISORY FROM 6 AM SATURDAY TO 6 AM AST SUNDAY FOR COASTAL WATERS OF NORTHERN USVI AND CULEBRA OUT 10 NM. && $$ |
| #531641 (Received by flhurricane at: 10:42 PM 03.Aug.2012) AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 932 PM CDT FRI AUG 3 2012 .DISCUSSION... A QUIET AND WARM EVENING ACROSS SE TX. A FEW HIGH CLOUDS ARE DRIFTING WEST WHICH ORIGINATED FROM CONVECTION WELL TO OUR EAST. MOISTURE LEVELS WILL INCREASE A LITTLE LATE TONIGHT AND EARLY TOMORROW ACROSS SE AREAS WHICH MAY LEAD TO SOME ISOLATED SHOWERS OFFSHORE NEAR THE COAST...BUT THINK INLAND AREAS WILL BE DRY OVERNIGHT. NO SIGNIFICANT CHGS ARE BEING MADE THIS EVE TO THE ONGOING FORECAST. STILL WATCHING TS ERNESTO MOVING WEST ACROSS THE FAR EASTERN CARRIBEAN. LATEST MODEL TRACK GUIDANCE STILL DIVERGING AFTER 3 DAYS INTO THE FORECAST. HOPEFULLY THE PICTURE WILL BECOME A LITTLE CLEARER FOR US LATER THIS WEEKEND CONCERNING ERNESTO`S FUTURE PATH NEXT WEEK. 33 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 76 98 76 98 76 / 0 10 10 20 10 HOUSTON (IAH) 79 94 78 94 75 / 0 20 10 30 10 GALVESTON (GLS) 83 91 82 91 80 / 0 20 20 30 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531639 (Received by flhurricane at: 10:41 PM 03.Aug.2012) AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 1025 PM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH SATURDAY/... 10PM UPDATE...NO CHANGES. PATCHY FOG STILL EXPECTED THROUGH MUCH OF THE NIGHT. PREV DISCUSSION... CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE. TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL. HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY. AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL BE LAST TO CLEAR DURING THE AFTERNOON. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT. DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE VFR. SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART. HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5 FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3 FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW. SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY DROPPING THEM BACK 1-2 FEET. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT/RUNYAN |
| #531640 (Received by flhurricane at: 10:41 PM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 1022 PM EDT FRI AUG 3 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL STALL OVER THE REGION TONIGHT... BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HOT AND HUMID CONDITIONS WILL CONTINUE TOMORROW AND SUNDAY. A STRONGER COLD FRONT WILL CROSS THE REGION LATE SUNDAY NIGHT OR MONDAY BRINGING ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE AREA. HIGH PRESSURE BUILDS OVER THE REGION MONDAY THROUGH WEDNESDAY WITH DRIER CONDITIONS EXPECTED. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... UPDATE...WILL INPUT CURRENT TEMPS AND DEW POINTS. WILL ALSO ADJUST THE AREA OF FOG. NO OTHER CHANGES. PREV DISC...WEAK FRONTAL BOUNDARY APPROACHING THE AREA THIS AFTERNOON FROM THE NORTHWEST. VISIBLE SATELLITE IMAGERY SHOWS DECENT CLEARING ACROSS MOST OF THE FORECAST AREA. MODIFIED 12Z KGYX SOUNDING INDICATES UPWARDS OF 2500J/KG WORTH OF CAPE TO WORK WITH. ALTHOUGH SHEAR IS WEAK...EXPECT SOME SCATTERED STORMS TO DEVELOP THIS AFTERNOON AND EVENING. SOME MAY BE STRONG ENOUGH TO REACH SEVERE LIMITS...BUT THEY SHOULD BE PRETTY ISOLATED. ONCE DIURNAL HEATING FADES CONVECTION SHOULD DIE OFF PRETTY QUICKLY. WITH DEWPOINTS STILL WELL INTO THE 60S...EXPECT FOG TO SET UP AGAIN ACROSS MUCH OF THE AREA. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... FOG AND STRATUS SHOULD BURN OFF DURING THE MORNING HOURS TOMORROW. FRONTAL BOUNDARY STALLED TO OUR SOUTH WILL START TO MAKE ITS WAY NORTHWARD AS A WEAK WARM FRONT. NOT MUCH LEFT IN THE WAY OF DYNAMICS WITH THE BOUNDARY AND SHOWERS AND THUNDERSTORMS MAY BE LIMITED TO WESTERN PORTIONS OF CWA AND THE MOUNTAINS. EXPECT CLEARING GOING INTO SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... SOUTHERLY FLOW TRANSPORTS MORE MOISTURE INTO THE REGION ON SUNDAY IN ADVANCE OF AN APPROACHING TROUGH. WILL PROBABLY SEE FOG ALONG THE COAST WHICH MAY LAST INTO THE AFTERNOON ESPECIALLY ON THE MIDCOAST. OUTSIDE OF FOGGY AREAS... TEMPERATURES WILL WARM WELL INTO THE 80S. TIMING OF THE TROUGH AND ASSOCIATED COLD FRONT SEEM TO SUGGEST THAT PRECIPITATION WILL BE LATER IN ARRIVING. SHOULD SEE A CHANCE OF SHOWERS AND THUNDERSTORMS LATE SUNDAY AFTERNOON AND THROUGH SUNDAY NIGHT. THIS TIMING MEANS THE SEVERE WEATHER THREAT WILL BE MINIMIZED. HOWEVER... EVEN WITH THE PASSAGE DURING THE NIGHTTIME HOURS IN THE ABSENCE OF SURFACE BASED INSTABILITY... INSTABILITY ALOFT GENERATED BY THE TROUGH AND COLD ADVECTION ALOFT MAY BE ENOUGH TO KEEP THUNDERSTORMS GOING. SHEAR WOULD BE SUFFICIENT FOR SUPERCELLS AND BOWING MULTICELL STORMS GIVEN ENOUGH INSTABILITY. COLD FRONT MAKES A FULL PASSAGE THROUGH THE AREA BY MONDAY MORNING OR EARLY MONDAY AFTERNOON. MAY STILL SEE SOME SHOWERS AND STORMS LINGERING AHEAD OF THE FRONT THROUGH EARLY MONDAY. OTHERWISE WILL SEE A CLEARING AND DRYING TREND AS HIGH PRESSURE BUILDS IN FROM THE WEST. HIGH PRESSURE GENERALLY HOLDS THROUGH TUESDAY... ALTHOUGH A WEAK SHORTWAVE TROUGH CROSSES JUST NORTH OF THE INTERNATIONAL BORDER. ANOTHER SHORTWAVE TROUGH DIGS FURTHER SOUTH ON WEDNESDAY AND THURSDAY... WITH SHOWERS AND THUNDERSTORMS POSSIBLE PRIMARILY DURING THE AFTERNOON EACH DAY OVER INTERIOR LOCATIONS. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM...EXPECT VFR CONDITIONS TO DETERIORATE TONIGHT TO IFR/LIFR CONDITIONS IN FOG. FOG WILL LIFT BY MID-MORNING TOMORROW WITH VFR CONDITIONS RETURNING AND REMAINING IN PLACE FOR THE REMAINDER OF THE SHORT TERM PERIOD. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...WILL PROBABLY SEE FOG RETURN SATURDAY NIGHT INTO EARLY SUNDAY ALONG THE COAST. FOG WILL LINGER LONGEST ALONG THE MIDCOAST NEAR ROCKLAND AND MAY EVEN LAST THROUGH THE AFTERNOON. EXPECT SHOWERS AND THUNDERSTORMS LATE SUNDAY THROUGH EARLY MONDAY. GENERALLY VFR AFTER THE COLD FRONT MOVES THROUGH ON MONDAY THROUGH THE MIDDLE OF THE WEEK. && .MARINE... SHORT TERM /THROUGH SATURDAY...A WEAK FRONT DROPS INTO THE GULF OF MAINE ON FRIDAY BEFORE DISSIPATING. WINDS AND SEAS SHOULD REMAIN FAIRLY QUIET. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...SOUTHERLY FLOW WILL INCREASE IN ADVANCE OF AN APPROACHING COLD FRONT ON SUNDAY. ALTHOUGH WINDS MAY STAY BELOW 25 KT... SEAS WILL GRADUALLY BUILD ON THE SOUTHERLY FETCH AND WAVE HEIGHTS MAY EXCEED 5 FEET. THE COLD FRONT WILL CROSS THE WATERS ON MONDAY WITH A RETURN TO MORE TRANQUIL CONDITIONS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ |
| #531637 (Received by flhurricane at: 10:39 PM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1020 PM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TONIGHT AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 PM FRI...ADDED ISOLATED TSTMS/20 POP TO CRYSTAL COAST BEACHES OVERNIGHT...REST OF FCST ON TRACK. ISOLATED CONVECTIVE ACTIVITY OFFSHORE TO S AND E WILL CONTINUE TO SPREAD TOWARD AREA OVERNIGHT...AND SEVERAL MESO MODELS CONTINUE TO INDICATE THIS ACTIVITY AFFECTING COASTAL SECTIONS TOWARD MORNING. MOSTLY CLEAR OVER AREA THIS EVENING EXCEPT FOR SOME CONVECTIVE DEBRIS OVER NW AND SOME SRLY FLOW SCU NEAR MRH-MHX. DEBRIS WILL CONTINUE TO SPREAD OVER AREA OVERNIGHT...THUS CONTINUED BECOMING PC FCST. NO CHANGES WITH TEMPS. /PREVIOUS DISCUSSION/ OVERNIGHT SHOULD SEE DIMINISHING SHOWERS AND THUNDERSTORMS INLAND WITH WIDELY SCATTERED SHOWERS AND TSTMS POSSIBLE OFF THE COAST. SW FLOW WILL KEEP TEMPS MILD OVERNIGHT WITH LOWS IN THE LOW 70S INLAND TO MID/UPPER 70S ALONG THE COAST. && .SHORT TERM /SATURDAY/... AS OF 340 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON HOURS. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL SHOWERS AND THUNDERSTORMS. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 00Z SUNDAY/... AS OF 730 PM FRI...VFR CONDITIONS EXPTECTED DURING TAF PERIOD EXCEPT FOR PERIOD OF MVFR VSBYS OVERNIGHT. SCT CONVECTIVE ACTIVITY HAS MOVED N OF AREA AND NO ADDITIONAL DEVELOPMENT EXPECTED OVERNIGHT. GUIDANCE SUGGEST FOG FORMATION OVERNIGHT GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER. ONLY MINOR MVFR HAS BEEN OBSERVED RECENTLY SO HEDGED TOWARDS CLIMO OF RECENT NIGHTS AND KEPT LOW MVFR FOR FOG OVERNIGHT. SAT WILL SEE CONTINUED S FLOW WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/ AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH LOCALLY LOWER CEILINGS/VISIBILITIES. && .MARINE... SHORT TERM /THROUGH SATURDAY/... AS OF 10 PM FRI...NO CHANGES WITH UPDATE. LIGHT TO MODERATE SRLY FLOW WILL CONTINUE OVERNIGHT WITH SEAS AROUND 3 FT. /PREVIOUS DISCUSSION/ AS OF 330 PM FRI...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE SOUTHERLY WINDS 8-12 KNOTS WITH MEDIUM PERIOD SWELLS 2-3 FEET AT 8-9 SECONDS. GOOD BOATING CONDITIONS ARE EXPECTED THROUGH SAT WITH LIGHT S/SW WINDS. WAVEWATCH AND LOCAL SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TONIGHT THROUGH SATURDAY. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/ AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND. THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DAG |
| #531636 (Received by flhurricane at: 10:30 PM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1001 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE SOUTHEAST COAST WILL ALLOW FOR WARM AND HUMID CONDITIONS ACROSS THE AREA THROUGH THE WEEKEND. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL ALSO CONTINUE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH THE REGION ON MONDAY RESULTING IN BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... LAST OF AFTN/EVE CONVECTION IS WANING ACROSS THE EASTERN PIEDMONT AS OF 10 PM. BASED ON CURRENT RADAR/SATELLITE TRENDS AND LATEST HI-RES MODEL GUIDANCE...AM NOT ANTICIPATING ADDITIONAL TSTM DEVELOPMENT OVERNIGHT. THEREFORE...WILL LIMIT SLIGHT CHC POPS TO ONLY OUR EASTERN PIEDMONT COUNTIES FOR THE NEXT COUPLE OF HOURS AND HAVE DRY WX EVERYWHERE ELSE. LOW TEMPS 70-75. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... SHORTWAVE TROUGH TO LIFT NE SATURDAY WITH BERMUDA HI PRESSURE EXPANDING WESTWARD. SWLY FLOW ALOFT WILL ALLOW FOR CONTINUED HUMID CONDITIONS WITH ABOVE NORMAL DAYTIME TEMPERATURES. A STRONG MID LEVEL SHORTWAVE WILL APPROACH THE GREAT LAKES REGION THROUGH THE WEEKEND. WEAK MID LEVEL DISTURBANCES WILL COMBINE WITH THE WARM AND HUMID AIRMASS TO PROVIDE ISOLATED/SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. TEMPERATURES THIS WEEKEND WILL RANGE FROM THE UPPER 80S TO LOW/MID 90S UNDER MOSTLY SUNNY TO PARTLY CLOUDY SKIES. HEAT INDICES EXPECTED TO REMAIN BELOW HEAT ADVISORY CRITERIA. A COLD FRONT IS PROGGED TO REACH CENTRAL VA BY MONDAY MORNING/AFTERNOON RESULTING IN MORE ORGANIZED AND WIDESPREAD CONVECTION MONDAY AFTERNOON. ATTM...GFS/ECMWF SOLUTIONS TEND TO BE MORE PROGRESSIVE/DEEPER WITH SFC TROUGH MONDAY THAN NAM/SREF SOLUTIONS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... WE HAVE ARRIVED AT THE TIME OF YEAR WHERE FRONTS HAVE A TUFF TIME MOVING SOUTH OF THE REGION DUE TO THE STRENGTH OF THE BERMUDA HIGH. NEXT WEEK WILL FEATURE ONE SUCH BOUNDARY THAT STALLS AND WEAKENS ACROSS THE REGION BY TUESDAY...LINGERS AS A LEE TROF WEDNESDAY AND THURSDAY WITH ANOTHER FRONTAL BOUNDARY APPROACHING FROM THE NORTH FRIDAY. RESULT WILL BE A TRIGGER FOR CHC POPS EACH DAY...CONCENTRATING ON THE AFTERNOON/EVENING HOURS. BEST MOISTURE AND HIGHEST POPS SEEN MONDAY NIGHT THROUGH WEDNESDAY. SLGHT CHC POPS THURSDAY EXCEPT CHC ACROSS THE SE. SLGHT CHC FRI FOR NOW. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... STRONG BERMUDA HIGH OVER THE ATLANTIC KEEPING SOUTHERLY FLOW ACROSS THE REGION. WIDELY SCATTERED CONVECTION MOSTLY WEST AND NORTH OF OF OUR REGION WILL PROBLY DIE BY AROUND 10 PM OR SOONER. GUIDANCE INDICATES WNDS AT 4-8 KTS OVERNIGHT. SOME PTCHY FOG WILL OCCUR BUT SHOULD NOT ADVERSELY AFFECT TAF LOCATIONS. HOWEVER WOULD NOT BE SURPRISED TO SEE SHORT PERIOD OF 2-3 MI VIS AT SBY/PHF/ECG DURING EARLY MORNING. LITTLE CHANGE IN THE PATTERN IS EXPECTED FOR SAT AND SUN WITH ISOLATED TO SCATTERED AFTN/EVENING TSTMS PSBL THRU THE WEEKEND. THERE WILL BE AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... NO FLAGS AS SRLY FLOW ARND BERMUDA HIGH PRESSURE DOMINATES THROUGH THE WEEKEND. SOME CHANELLING UP THE BAY TONIGHT AND SAT NIGHT WILL KEEP WINDS BTWN 10-15 KTS. INCRG PRESSURE GRADIENT AHEAD OF APPRCHG BOUNDARY/TROF MAY RESULT IN MINIMAL SCA CONDITIONS SUN NIGHT / MON. BOUNDARY STALLS/WEAKENS OVER THE REGION EARLY NEXT WEEK WITH SW FLOW CONTINUING. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...SAM |
| #531635 (Received by flhurricane at: 10:29 PM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1013 PM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL INTO EARLY NEXT WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A STATIONARY FRONT WILL STALL NORTH OF THE AREA MID TO LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... ISOLATED SHOWERS/THUNDERSTORMS COULD CONTINUE TO DEVELOP ALONG MESOSCALE BOUNDARIES ACROSS FAR S/W COUNTIES FOR ANOTHER FEW HOURS. ALSO...OUTFLOW BOUNDARIES PRODUCED BY MORE NUMEROUS THUNDERSTORMS JUST INLAND FROM THE FORECAST AREA COULD PUSH BACK INTO THE REGION AND COULD ENHANCE/EXTEND THUNDERSTORM DEVELOPMENT/COVERAGE ACROSS FAR INLAND COUNTIES INTO THE OVERNIGHT HOURS. FOR NOW... MAINTAINED SLIGHT CHANCE POPS ACROSS FAR S/W COUNTIES UNTIL 2 AM. OVERNIGHT...THE 00Z NAM CONTINUES TO SUGGEST THAT SHOWERS/ THUNDERSTORMS WILL EVENTUALLY WANE AND SHIFT FARTHER INLAND FROM THE FORECAST AREA. LATE TONIGHT/EARLY SATURDAY...ONSHORE FLOW/LOCALIZED CONVERGENCE COULD SUPPORT ISOLATED SHOWERS/THUNDERSTORMS OVER COASTAL COUNTIES/ADJACENT COASTAL WATERS. MAINTAINED ONGOING SLIGHT CHANCE POPS FOR THIS SCENARIO... BUT THE 00Z NAM SUGGESTS THAT NO PRECIPITATION WILL OCCUR OVER COASTAL WATERS UNTIL AFTER 12Z. TEMPERATURES WILL BOTTOM OUT IN THE MID 70S INLAND AND AROUND 80F AT THE COAST LATE TONIGHT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... A DEEP LAYER RIDGE...STRETCHING FROM THE ATLANTIC...WESTWARD ACROSS THE SOUTHERN AND CENTRAL U.S....WILL PERSIST THROUGH THE PERIOD. A TROPICAL WAVE WELL SOUTH OF THE AREA OVER THE BAHAMAS...IS EXPECTED TO REMAIN SOUTH OF THE REGION AS IT MOVES WESTWARD ACROSS CENTRAL FLORIDA AND THEN INTO THE WESTERN GULF OF MEXICO BY EARLY NEXT WEEK. THE GLOBAL MODELS KEEP THIS TROPICAL WAVE WEAK...AND PUSH THE NORTHERN FRINGE OF THE ASSOCIATED MOISTURE ACROSS THE REGION SATURDAY AND SUNDAY...THEN WEST OF THE REGION BY LATER SUNDAY AND MONDAY. HOWEVER...THE NAM IS MUCH SLOWER WITH THE PROGRESSION OF MOISTURE ASSOCIATED WITH THIS TROPICAL WAVE. THE NAM BRINGS IN THE BEST MOISTURE ACROSS THE AREA LATE SATURDAY NIGHT...THEN PERSISTING THROUGH MONDAY. IF THE NAM IS MORE CORRECT...POPS WILL NEED TO BE RAISED FOR SUNDAY AND MONDAY. WILL CONTINUE TO MONITOR LATER NAM SOLUTIONS. FOR NOW...HAVE KEPT GENERALLY CLIMO /CHC/ POPS...CENTERED AROUND THE AFTERNOON/EVENING HEATING...BUT AS MENTIONED ABOVE...POPS MAY NEED TO BE NUDGED HIGHER IS DEEPER MOISTURE ASSOCIATED WITH THE NORTHERN FRINGE OF THE TROPICAL WAVE IMPACTS THE REGION THIS WEEKEND. SOUTHEAST LOW LEVEL FLOW SHOULD HELP TO FOCUS SCATTERED AFTERNOON/EVENING CONVECTION INLAND. WITH NO APPRECIABLE UPPER LEVEL FEATURES TO FORCE CONVECTION...EXPECT MESOSCALE BOUNDARIES AND SEA BREEZE TO BE THE PRIMARY FOCUS FOR CONVECTION. TEMPS EXPECTED TO NEAR NORMAL THROUGH THE PERIOD...HIGHS IN THE LOWER 90S AND LOWS IN THE MID 70S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL RIDGING WILL BEGIN TO WEAKEN EARLY NEXT WEEK...AS A TROUGH ALOFT AND SEVERAL SHORTWAVES MOVE ACROSS THE NEW ENGLAND STATES. AN ASSOCIATED COLD FRONT WILL LIKELY STALL WELL TO THE NORTH OF THE FORECAST AREA BY THE MIDDLE OF NEXT WEEK. AT THE SURFACE...THE INLAND TROUGH COULD BECOME MORE PROMINENT BETWEEN SURFACE HIGH PRESSURE OVER THE CENTRAL UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. CONSIDERING THE INCREASED FORCING FROM THE STALLED FRONT TO THE NORTH...COMBINED WITH INFLUENCES FROM THE LEE TROUGH AND BOUNDARY/SEABREEZE INTERACTIONS...CONVECTIVE POTENTIAL COULD BE GREATER THROUGH THE EXTENDED PERIOD. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS...WITH HIGH TEMPERATURES IN THE LOW TO MID 90S DURING THE AFTERNOON FALLING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... VFR THROUGH SATURDAY. THE PROBABILITY FOR THUNDERSTORMS IN THE VICINITY OF THE TERMINALS REMAINS TOO LOW TO JUSTIFY A MENTION WITHIN 00Z TAFS FOR SATURDAY AFTERNOON. EXTENDED AVIATION OUTLOOK...MAINLY VFR. ISOLATED AFTERNOON CONVECTION POSSIBLE EACH DAY...WITH BRIEF PERIODS OF SUB-VFR CONDITIONS POSSIBLE. && .MARINE... OVERNIGHT...S/SE WINDS WILL CONTINUE TO AVERAGE 10-15 KT WITH OCCASIONAL GUSTS TO 20 KT...THEN WINDS COULD DIMINISH SOMEWHAT FOR A TIME TOWARD DAYBREAK. SEAS WILL REMAIN 2-3 FT OVERNIGHT. A ATLANTIC RIDGE OF HIGH PRESSURE WILL REMAIN CENTERED JUST NORTH OF THE REGION THROUGH THE WEEKEND...THEN DRIFT SOUTHWARD OVER THE REGION MONDAY THROUGH WEDNESDAY. SOUTHEAST WINDS OF 15 KTS OR LESS AND SEAS 4 FT OR LESS EXPECTED THROUGH THE PERIOD. A WEAK TROPICAL WAVE IS EXPECTED TO MOVE WELL SOUTH OF THE REGION ACROSS CENTRAL FLORIDA THIS WEEKEND AND INTO EARLY NEXT WEEK. THERE COULD BE AN INCREASE OF SHOWERS AND THUNDERSTORMS BY LATER THIS WEEKEND AS THE MOISTURE ASSOCIATED WITH THIS WAVE GLANCES THE REGION. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531634 (Received by flhurricane at: 10:23 PM 03.Aug.2012) AFDMOB AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MOBILE AL 901 PM CDT FRI AUG 3 2012 .UPDATE...PUTTING THE FINISHING TOUCHES ON THE EVENING UPDATE PACKAGE AND WILL SHIP UPDATED FORECAST SHORTLY. LINGERING LIGHT RAINS FROM EARLY EVENING STORMS ARE DIMINISHING RAPIDLY AND SHOULD BE GONE BY 04Z. EXPECT THE AIRMASS TO REMAIN FAIRLY STABILIZED OVER MOST LAND AREAS THROUGH EARLY MORNING AND DONT REALLY EXPECT ANY ADDITIONAL THUNDER OVERNIGHT...BUT WE DO SEE ANOTHER WEAK SHORTWAVE ROUNDING THE SOUTHERN PLAINS RIDGE BY EARLY MORNING AND THERE IS A SMALL POSSIBILITY A FEW STORMS COULD DEVELOP NORTH OF OUR AREA TOWARD MORNING...SO WE WILL LEAVE A 20 POP (SLIGHT CHANCE) GOING TOWARD MORNING OVER OUR AREA. WE WILL BE ADDING A MENTION OF PATCHY RADITIONAL FOG TO THE FORECAST FOR LATE TONIGHT IN AREAS WHERE THE RAIN WAS MORE EXTENSIVE TODAY. REST OF FORECAST ON TRACK. /05 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$ |
| #531633 (Received by flhurricane at: 10:18 PM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 943 PM EDT FRI AUG 3 2012 .SYNOPSIS... A VERY WARM AND HUMID WEEKEND ALONG WITH MAINLY DRY WEATHER IS ON TAP. A COLD FRONT WILL BRING A ROUND OF SHOWERS AND THUNDERSTORMS...MAINLY SUN NIGHT INTO EARLY MON. DRY WEATHER FOLLOWS FOR THE MIDDLE OF NEXT WEEK...WITH PERHAPS A FEW MORE SHOWERS/THUNDERSTORMS NEXT THU AND/OR FRI. && .NEAR TERM /THROUGH SATURDAY/... 945 PM UPDATE... FOG/STRATUS REMAINS OVER CAPE COD AND ISLANDS AND WITH LOW LEVEL SW FLOW SHOULD PRETTY MUCH REMAIN WHERE IT IS OVERNIGHT...THOUGH WE WILL ALSO SEE PATCHY FOG ACROSS INTERIOR. DRY AIR AT MID LEVELS PER 00Z SOUNDINGS PREVENTED ANY CONVECTION FROM DEVELOPING THIS EVENING DESPITE PLENTY OF INSTABILITY. HRRR STILL TRIES TO GENERATE A FEW SHOWERS OR STORMS OVERNIGHT BUT THIS APPEARS TO BE OVERDONE. FORECAST LOWS IN 60S AND LOWER 70S ARE ON TRACK. && .SHORT TERM /SATURDAY NIGHT/... SAT... TRICKY FORECAST TOMORROW AS ALL MODEL GUIDANCE /TO VARYING DEGREES/ HAS QPF ACROSS THE AREA AND THEN LIFTING NORTHWARD WITH TIME. THIS SEEMS SOMEWHAT REASONABLE AS WEAK SURFACE TROUGH LIFTS NORTH AS A WARM FRONT. SO THIS BOUNDARY COULD PROVIDE A FOCUS FOR CONVECTION. HOWEVER PATTERN RECOGNITION WOULD SUGGEST A CAPPED ENVIRONMENT WITH RISING MID LEVEL HEIGHTS AS SUBTROPICAL RIDGE BUILDS NORTHWEST INTO SOUTHERN NEW ENGLAND. IN ADDITION MID LEVEL FLOW IS ANTICYCLONIC PROVIDING SUBSIDENCE. MOS POPS REFLECT THIS IDEA WITH ONLY SLIGHT CHC POPS FROM THE METNAM AND MAVGFS. THUS WILL GO WITH SLIGHT CHANCE POPS. GIVEN THE LACK OF DEEP LAYER SHEAR THE MAIN RISK WITH ANY TSTM WILL BE BRIEF HEAVY RAIN. MUCH OF THE DAY SHOULD BE DRY ALONG WITH VERY WARM AND HUMID CONDITIONS CONTINUING. SAT NIGHT... MAINLY WARM...MUGGY AND DRY BUT A LOW RISK OF SHOWERS/TSTMS TOWARD SUNDAY MORNING AS MID LEVEL FLOW BECOMES CYCLONIC WITH APPROACHING SHORT WAVE TROUGH. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGHLIGHTS... *SHOWERS/STORMS LIKELY SUN NIGHT AND/OR EARLY MON WITH HEAVY RAINFALL *SEASONABLE AND MAINLY DRY WEATHER FOR THE MIDDLE OF NEXT WEEK *A FEW SHOWERS/STORMS POSSIBLE AGAIN BY LATE NEXT WEEK DETAILS... SUNDAY AND MONDAY... LOW CONFIDENCE ON TIMING OF THE BULK OF THE PRECIPITATION AS CONSIDERABLE MODEL DIFFERENCES REMAIN. EXPECT MUCH OF THE DAYLIGHT HOURS TO BE DRY ON SUNDAY...OTHER THAN PERHAPS A FEW BRIEF SPOT SHOWERS/THUNDERSTORMS. THE BULK OF THE ACTIVITY SHOULD ARRIVE SOMETIME SUNDAY NIGHT AND POSSIBLY INTO EARLY MONDAY AHEAD OF THE COLD FRONT. THE MAIN CONCERN WITH THIS ACTIVITY WILL BE HEAVY RAINFALL/LOCALIZED FLOODING GIVEN PWATS ON THE ORDER OF 2 TO 2.5 INCHES. SEVERE WEATHER POTENTIAL LOOKS LOW GIVEN WEAK MID LEVEL LAPSE RATES AND AN UNFAVORABLE TIME OF ARRIVAL. HOWEVER...CAN/T COMPLETELY RULE OUT A FEW STRONG THUNDERSTORMS. TUESDAY AND WEDNESDAY... A WEAK RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE COLD FRONT. DRY WEATHER SHOULD DOMINATE OVER THIS TIME ALONG WITH FAIRLY SEASONABLE TEMPERATURES. THURSDAY AND FRIDAY... UPPER LEVEL TROUGH/COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS WILL BRING THE CHANCE OF A ROUND OR TWO OF SCATTERED SHOWERS/THUNDERSTORMS...BUT LOW CONFIDENCE ON TIMING. ALSO...NOT EXPECTING A WASHOUT AS MUCH OF THE TIME WILL PROBABLY FEATURE DRY WEATHER. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW... TONIGHT...CONFIDENCE IS LOW ON IFR CEILINGS REDEVELOPING. CURRENT THINKING IS THAT MOST OF IT WILL BE CONFINED TO PORTIONS OF THE SOUTH COAST/CAPE COD/ISLANDS. HOWEVER...AREAS OF PATCHY FOG WILL LIKELY RESULT IN LOCALIZED MVFR-IFR CONDITIONS LATE ACROSS OTHER AREAS. SAT...ANY IFR CAPE COD AND ISLANDS WILL BURN OFF BY MIDDAY. OTHERWISE VFR WITH JUST A LOW PROB OF AN ISOLATED TSTM IN THE AFTN. KBOS TAF...HIGH CONFIDENCE. MAINLY VFR TONIGHT AND SATURDAY. HOWEVER...BRIEF MVFR VISIBILITIES ARE POSSIBLE EARLY SAT. VERY LOW PROB OF AN ISOLATED TSTM SAT AFTN. KBDL TAF...MODERATE TO HIGH CONFIDENCE. MAINLY VFR CONDITIONS TONIGHT AND SATURDAY...ALTHOUGH A PERIOD OF MVFR VISIBILITIES ARE LIKELY LATE TONIGHT/EARLY SAT IN FOG. VERY LOW PROB OF AN ISOLATED TSTM SAT AFTN. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN LOW CLOUDS AND FOG EARLY SUN WILL PROBABLY TEMPORARILY IMPROVE. HOWEVER...MVFR-IFR CONDITIONS SHOULD OCCUR AGAIN SUN NIGHT/EARLY MON IN SOME SHOWERS/THUNDERSTORMS. TUESDAY AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE IN MAINLY VFR CONDITIONS. && .MARINE... SW WINDS WILL SLOWLY DIMINISH BY MIDNIGHT ON S COASTAL WATERS WHERE WE ARE STILL SEEING SOME 20KT GUSTS. OTHERWISE MAIN CONCERN IS PATCHY DENSE FOG AROUND CAPE COD AND ISLANDS. SAT... LIGHT SSW WINDS CONTINUE. NOT MUCH WIND WAVE OR SWELL EXPECTED. VSBY MAY BE REDUCED IN PATCHY DENSE FOG DURING THE MORNING. CONFIDENCE IS LOW ON AREAL EXTENT BUT ANY FOG SHOULD BURN OFF BY MIDDAY. VERY LOW RISK OF A SHOWER/TSTM BUT MUCH OF THE DAY SHOULD BE DRY. SAT NIGHT... MORE OF THE SAME...LIGHT BUT MOIST SSW WINDS YIELDING PATCHY DENSE FOG LATE. OUTLOOK...SUNDAY THROUGH WEDNESDAY... MODERATE TO HIGH CONFIDENCE. SUNDAY AND MONDAY... INCREASING SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL BUILD SEAS TO ABOVE SCA THRESHOLDS ACROSS THE SOUTHERN WATERS LATE SUN THROUGH MON NIGHT. IN ADDITION...WIND GUSTS OF 20 TO 25 KNOTS CAN BE EXPECTED. THE OTHER BIG CONCERNS FOR MARINERS WILL BE AREAS OF FOG AND THE POTENTIAL FOR SOME THUNDERSTORMS SUN NIGHT INTO MON. TUESDAY AND WEDNESDAY... ANY LINGERING SCA FOR SEAS SHOULD DIMINISH ACROSS THE SOUTHERN WATERS DURING THE DAY TUE. OTHERWISE...RELATIVELY WEAK PRESSURE GRADIENT SHOULD KEEP WINDS AND SEAS BELOW SCA THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ004>006- 009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANK/NOCERA |
| #531632 (Received by flhurricane at: 10:15 PM 03.Aug.2012) AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 400 PM HST FRI AUG 3 2012 .SYNOPSIS... MODERATE TRADE WINDS WILL PREVAIL THROUGH THE WEEK. CONDITIONS WILL REMAIN ON THE DRY SIDE OF AVERAGE...WITH MOST SHOWERS CONFINED TO WINDWARD SLOPES AS WELL AS THE KONA SLOPES OF THE BIG ISLAND EACH AFTERNOON. && .DISCUSSION... TRADE WINDS WILL HOLD AT MODERATE STRENGTH ACROSS THE ISLANDS THROUGH THE UPCOMING WEEK. THE NORTH PACIFIC IS UNDER A RATHER UNUSUAL AND SLOWLY EVOLVING PATTERN. PERSISTENT TROUGHING THROUGH THE DEPTH OF THE ATMOSPHERE LINGERS ABOUT 1000 MILES NORTH OF THE ISLANDS AND EXTENDS TO THE WEST SOUTHWEST TO JUST NORTH OF MIDWAY ATOLL. THIS FEATURE HAS SPLIT THE SUBTROPICAL HIGH THAT NORMALLY RESIDES TO THE NORTH OF HAWAII...BUT THE PRESSURE GRADIENT OVER THE ISLANDS REMAINS STRONG ENOUGH TO PRODUCE MODERATE TRADES. THIS PATTERN WILL CHANGE LITTLE THROUGH EARLY NEXT WEEK...ALLOWING TRADES TO HOLD MORE OR LESS AT THE CURRENT STRENGTH. A TYPICAL WINDWARD AND MAUKA SHOWER PATTERN WILL CONTINUE THROUGH MUCH OF THE UPCOMING WEEK...WITH RAINFALL TOTALS ON THE DRY SIDE. THE ISLANDS LIE UNDER A TRANSITION ZONE BETWEEN THE ABOVE MENTIONED MID TO UPPER LEVEL TROUGH AND STRONG UPPER LEVEL RIDGING TO THE SOUTH. THIS WILL MAINTAIN STABLE CONDITIONS OVER THE ISLANDS... ALTHOUGH THE INVERSION MAY BE A BIT HIGHER AND SHOWER CHANCES SLIGHTLY GREATER NEAR KAUAI AT TIMES. THE UPWIND TRADE FLOW LOOKS TO REMAIN SLIGHTLY DRIER THAN AVERAGE...SO EXPECT RAINFALL TOTALS TO REMAIN MODEST. FOR TONIGHT...A WEDGE OF DRIER AIR IS LOOKING TO TAKE AIM AT THE BIG ISLAND...SO ITS LOOKING LIKE A DRY NIGHT FOR WINDWARD BIG ISLAND. WINDWARD RAINFALL ON THE OTHER ISLANDS WILL BE MODEST. THE STATE WILL EXPERIENCE PERIODS OF HIGH CLOUDS THROUGH EARLY NEXT WEEK...MAINLY ACROSS THE NORTHERN ISLANDS. FORECAST MODELS ARE SHOWING A SURFACE LOW DEVELOPING IN THE ABOVE MENTIONED UPPER LEVEL TROUGH SOMEWHERE BETWEEN MIDWAY AND LAYSAN ON SATURDAY OR SUNDAY. PORTIONS OF THE NORTHWEST HAWAIIAN ISLANDS WILL LIKELY EXPERIENCE THUNDERSTORMS AND GUSTY WINDS INTO MONDAY. THIS FEATURE WILL HAVE NO IMPACT HERE ON THE MAIN HAWAIIAN ISLANDS ASIDE FROM PERIODS OF HIGH CLOUDS FROM ABOUT SUNDAY THROUGH EARLY NEXT WEEK. && .MARINE... NO MARINE ADVISORIES ARE IN EFFECT...BUT BORDERLINE WINDS WILL PERSIST ACROSS THE TYPICALLY WINDY WATERS AND CHANNELS SURROUNDING THE BIG ISLAND AND MAUI THROUGH EARLY NEXT WEEK. ONLY SMALL SWELLS ARE IN STORE...INCLUDING SOME POSSIBLE ENERGY FROM THE WEST DURING THE FIRST PART OF NEXT WEEK. SEE THE COLLABORATIVE NEARSHORE SWELL AND WIND FORECAST FOR DETAILS. && .AVIATION... VFR CONDITIONS WILL DOMINATE MOST AREAS THROUGH THE NIGHT. && .FIRE WEATHER... THE KEETCH BYRAM DROUGHT INDEX /KBDI/ MEASURED AT HONOLULU WILL TOP THE CRITICAL 600 MARK THIS WEEKEND. THIS INDEX IS CRUCIAL FOR FIRE WEATHER WATCH AND RED FLAG WARNING DECISION MAKING. THE WINDY AND DRY CONDITIONS NEEDED FOR CRITICAL FIRE WEATHER CONDITIONS IS NOT ANTICIPATED THROUGH AT LEAST EARLY NEXT WEEK. && .HFO WATCHES/WARNINGS/ADVISORIES... NONE. && $$ |
| #531631 (Received by flhurricane at: 10:15 PM 03.Aug.2012) AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 938 PM EDT FRI AUG 3 2012 .SYNOPSIS... AN AREA OF HIGH PRESSURE IN THE WESTERN ATLANTIC WILL REMAIN IN PLACE THROUGH SATURDAY. A COLD FRONT IS THEN SCHEDULED TO ARRIVE LATE SUNDAY, BEFORE SLOWLY SHIFTING EASTWARD MONDAY. THIS FRONT MAY STALL NEARBY BEFORE A SECONDARY COLD FRONT ARRIVES WEDNESDAY INTO THURSDAY. THIS FRONT MAY THEN DISSIPATE AS YET ANOTHER COLD FRONT ARRIVES LATE THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... THE LAST OF TODAY`S CONVECTION IN OUR REGION DISSIPATED OVER UPPER BUCKS COUNTY AROUND 730 PM AS WE CONTINUED TO LOSE THE HEATING OF THE DAY. THERE WAS ISOLATED SEVERE WEATHER FROM EXTREME NORTHEASTERN MARYLAND AND NORTHERN DELAWARE INTO LOWER BUCKS COUNTY IN PENNSYLVANIA AND NORTHERN OCEAN COUNTY IN NEW JERSEY. NO ADDITIONAL PRECIPITATION IS ANTICIPATED OVERNIGHT. WE ARE EXPECTING HIGH CLOUDS, A LIGHT SOUTHERLY SURFACE FLOW AND TEMPERATURES DROPPING MAINLY INTO THE UPPER 60S AND LOWER 70S. WITH PLENTY OF LOW LEVEL MOISTURE IN OUR REGION, PATCHY FOG AND STRATUS IS POSSIBLE LATE TONIGHT, ESPECIALLY IN AREAS THAT RECEIVED RAIN TODAY. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... THE BERMUDA HIGH REMAINS TO THE EAST OF THE AREA AND WILL CONTINUE TO INFLUENCE OUR WEATHER. HOT HUMID AIR MASS REMAINS ACROSS THE REGION WITH A SOUTHERLY FLOW BECOMING A BIT MORE TO THE SOUTHEAST THROUGH THE DAY. WINDS START TO PICK UP LATER IN THE DAY AS LOW PRESSURE STARTS TO PUSH EASTWARD, CREATING A TIGHTER PRESSURE GRADIENT ACROSS OUR AREA. TEMPERATURES SHOULD REACH INTO LOWER 90S ACROSS MOST OF THE AREA WITH SOME UPPER 80S IN THE HIGHER TERRAIN OF NORTHWESTERN NEW JERSEY AND SOUTHERN POCONOS. DEWPOINTS WILL BE SIMILAR TO FRIDAYS AND BE IN THE UPPER 60S TO LOWER 70S. WHILE THIS WILL KEEP IT FEELING HUMID OUTSIDE, HEAT INDEX VALUES LOOK TO FALL SHORT OF ADVISORY LEVELS SO WE ARE NOT EXTENDING ANY HEAT HEADLINES WITH THIS PACKAGE. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE OVERALL SYNOPTIC PATTERN IS COMPRISED OF A ROBUST SHORT WAVE TROUGH THAT WILL MOVE FROM THE MIDWEST SATURDAY NIGHT TO THE NORTHEAST SUNDAY NIGHT INTO MONDAY. GIVEN THE STRENGTH OF THIS FEATURE, LOCALLY STRONG TO POTENTIALLY SEVERE CONVECTION MAY OCCUR LATER SUNDAY. THIS SHORT WAVE TROUGH THEN LOOKS TO WEAKEN SOME AS A LARGER TROUGH BECOMES ESTABLISHED ACROSS EASTERN CANADA AND A RIDGE PERSISTS IN THE SOUTHWESTERN ATLANTIC. THIS TROUGH THEN TENDS TO SETTLE SOUTHWARD SOME FROM THE MIDWEST TO THE NORTHEAST. THE OVERALL FLOW THOUGH MAY WEAKEN AS THE MAIN TROUGH WEAKENS NORTHEASTWARD, WHICH MAY END UP LEADING TO A COUPLE OF SURFACE COLD FRONTS SLOWING OR STALLING NEAR OUR REGION FROM LATE MONDAY ONWARD. WE USED MOSTLY A MODEL BLEND APPROACH FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT, THEN FOLLOWED FAIRLY CLOSELY TO HPC GUIDANCE THEREAFTER. HPC USED A GFS/ECMWF BLEND TO WEDNESDAY THEN AN EVEN BLEND OF THE ENSEMBLE MEAN AND NAEFS MEAN FOR THURSDAY AND FRIDAY. FOR SATURDAY NIGHT, ANY ISOLATED TO SCATTERED CONVECTION SHOULD DISSIPATE DURING THE EVENING HOURS AS IT SHOULD BE MOSTLY DRIVEN BY AIR MASS HEATING. THIS SCENARIO LOOKS TO FAVOR ANY CONVECTION TENDING TO HOLD INLAND AND ESPECIALLY FROM INTERSTATE 95 WESTWARD. OTHERWISE, A MUGGY NIGHT WITH SOME LINGERING MAINLY MID TO HIGH LEVEL CLOUDS. GIVEN THE AMOUNT OF LOW-LEVEL MOISTURE FORECAST TO BE IN PLACE ALONG WITH A LIGHT SOUTHERLY FLOW, PERHAPS SOME PATCHY STRATUS DEVELOPS. A ROBUST SHORT WAVE TROUGH WILL THEN START TO APPROACH LATE, AND SOME LOW-LEVEL WAA MAY ALLOW FOR A SMALL CHC FOR CONVECTION TO REDEVELOP OVERNIGHT. OUR CONFIDENCE IN THIS IS LOW GIVEN THE MAIN ASCENT HOLDING BACK WELL TO OUR WEST. FOR SUNDAY AND MONDAY, THIS LOOKS TO POTENTIALLY FEATURE A PERIOD OF ACTIVE CONVECTIVE WEATHER /SUNDAY/. A RATHER ROBUST SHORT WAVE TROUGH WILL BE WORKING EASTWARD FROM THE GREAT LAKES, HOWEVER THE TIMING OF THIS FEATURE LOOKS SLOW ENOUGH TO THROTTLE BACK/DELAY THE POPS SOME FROM WEST TO EAST. THE MODEL GUIDANCE INDICATES A DECENT LOW TO MID LEVEL WIND FIELD ARRIVING FROM THE WEST, ALTHOUGH THE STRONGER SHEAR IS FORECAST TO SLIDE MOSTLY TO OUR WEST AND NORTH AS THE UPPER-LEVEL TROUGH AXIS LIFTS NORTHEASTWARD A BIT. THE GUIDANCE INDICATES THAT PLENTY OF INSTABILITY WILL BE IN PLACE ACROSS OUR AREA, AND WITH AMPLE HEATING TAKING PLACE A PRE-FRONTAL TROUGH SHOULD SET UP. THIS MAY PROVIDE ENOUGH LOW- LEVEL CONVERGENCE FOR ISOLATED TO SCATTERED CONVECTION TO DEVELOP. IT LOOKS HOWEVER THAT WE WILL HAVE TO WAIT FOR THE MAIN ASCENT WITH THE UPPER-LEVEL TROUGH TO ARRIVE TO FORCE MORE ORGANIZED CONVECTION, WHICH MAY TEND TO BE IN THE FORM OF CLUSTERS AND/OR LINE SEGMENTS. THIS TIMING WOULD TEND TO BRING THIS INTO OUR WESTERN ZONES IN THE AFTERNOON AND THEN DURING THE NIGHT ACROSS OUR EASTERN AND SOUTHERN ZONES. WHILE THE CONVECTION MAY WEAKEN DURING THE OVERNIGHT, INSTABILITY HOLDING ON ALONG WITH THE PASSAGE OF THE UPPER-LEVEL TROUGH AND SURFACE COLD FRONT SHOULD BE ENOUGH TO SUSTAIN AT LEAST SOME CONVECTION. GIVEN THE INSTABILITY AND THERMODYNAMIC PROFILES /RELATIVELY HIGH MOISTURE CONTENT AND STEEPENING LOW-LEVEL LAPSE RATES/, SOME OF THE CONVECTION MAY BECOME SEVERE ESPECIALLY IF STORMS CAN INITIATE EARLIER. IN ADDITION, THE SEVERE THREAT MAY TEND TO INCREASE IF ORGANIZED COLD POOLS WITHIN LINE SEGMENTS OR CLUSTERS CAN BECOME ESTABLISHED WHICH WOULD ENHANCE THE DOWNBURST WIND POTENTIAL. THEREFORE, LOCALLY GUSTY TO DAMAGING WINDS LOOK TO BE THE MAIN THREAT. IF STORMS ARE ABLE TO SUSTAIN STRONG UPDRAFTS, THEN LARGER HAIL WOULD ALSO BECOME A CONCERN. DESPITE THE POTENTIAL FOR A LATER ARRIVAL, THERE IS AT LEAST SOME STRONG CONVECTIVE WIND POTENTIAL THEREFORE ADDED GUSTY WINDS IN THE FORECAST. GIVEN A RATHER MOIST AND UNSTABLE AIR MASS, ROBUST ENOUGH UPDRAFTS MAY PRODUCE A LOT OF LIGHTNING, THEREFORE ADDED THIS AS WELL. WE WILL ALSO CONTINUE THE MENTION OF POSSIBLE STRONG TO SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK. BASED ON THE MODEL CONSENSUS, WE SLOWED DOWN THE POP INCREASE FROM WEST TO EAST A DECENT AMOUNT. THE COLD FRONT THEN GRADUALLY SLIDES SOUTHEASTWARD MONDAY WITH SOME SHOWERS AND STORMS POSSIBLY LINGERING MAINLY ACROSS OUR EASTERN AND SOUTHERN ZONES THROUGH MIDDAY. THERE MAY BE ENOUGH OF A SOUTHEASTERLY PUSH FROM AN INCOMING SURFACE HIGH TO REDUCE THE CONVECTIVE THREAT THE FARTHER NORTHWEST ONE GOES ACROSS OUR CWA. AS A RESULT, WE SHAVED THE POPS BACK FROM NORTHWEST TO SOUTHEAST WITH TIME. THE DRIER AIR HOWEVER MAY BE DELAYED IN ARRIVING ACROSS THE BULK OF OUR CWA AS THE SURFACE FRONT MAY TEND TO SLOW OR EVEN STALL. FOR TUESDAY AND WEDNESDAY, AN UPPER-LEVEL TROUGH GENERALLY BECOMES MORE AND MORE ESTABLISHED ACROSS THE NORTHEAST. THIS SHOULD FAVOR THE AFOREMENTIONED COLD FRONT STALLING NEAR THE NORTHERN MID ATLANTIC REGION. THIS BOUNDARY LOOKS TO WASH OUT WITH TIME AS SOME TROUGH AMPLIFICATION OCCURS UPSTREAM AND SENDS A SECONDARY COLD FRONT OUR WAY WEDNESDAY. SOME LOWERING HEIGHTS ALOFT ONCE AGAIN COMBINED ESPECIALLY WITH HEATING AND TERRAIN AFFECTS MAY BE ENOUGH TO ALLOW FOR ISOLATED TO SCATTERED SHOWERS AND STORMS ESPECIALLY WEDNESDAY AFTERNOON AND EVENING. FOR NOW, WE LEANED MORE TOWARD SLIGHT CHC POPS AS COVERAGE LOOKS TO BE LIMITED. FOR THURSDAY AND FRIDAY, AS THE UPPER-LEVEL TROUGH IS MAINTAINED IN THE NORTHEAST, ADDITIONAL ENERGY ROUNDING ITS BASE MAY KEEP THE SURFACE FRONTS SLOW MOVING OR EVEN STALL INTO THE MID ATLANTIC. A LEE SIDE TROUGH MAY BECOME PRESENT DURING BOTH OF THESE DAYS BEFORE ANOTHER SURFACE COLD FRONT ARRIVES LATE THURSDAY AND FRIDAY. THE OVERALL TROUGHING/CYCLONIC FLOW ABOVE SURFACE HEATING MAY LEAD TO SOME MAINLY DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. THE MAIN FORECAST CHALLENGE THIS FAR OUT IS MOSTLY COVERAGE. GIVEN LOWER CONFIDENCE, WENT WITH SLIGHT CHC TO LOW CHC POPS. AS FOR TEMPERATURES, WE USED MOSTLY A MOS BLEND FOR SATURDAY NIGHT THROUGH MONDAY THEN CLOSER TO HPC GUIDANCE. SOME ADJUSTMENTS WERE THEN MADE AFTER SOME ADDITIONAL COLLABORATION. SUNDAY LOOKS TO BE ANOTHER VERY WARM TO HOT DAY, HOWEVER HEAT INDICES ATTM LOOK TO STAY BELOW ADVISORY CRITERIA EVEN FOR THE PHILADELPHIA METRO AREA. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. FOR THE FIRST PART OF THE NIGHT, MAINLY VFR CONDITIONS ARE ANTICIPATED WITH A LIGHT WIND, FAVORING THE SOUTH, IF ANY DIRECTION AT ALL. WITH A FAIR AMOUNT OF LOW LEVEL MOISTURE IN PLACE, WE HAVE FORECAST MVFR VISIBILITY RESTRICTIONS FOR LATE TONIGHT AND EARLY SATURDAY MORNING. SOME PATCHY STRATUS MAY ALSO DEVELOP. BASED ON RECENT MORNINGS AND THE RAINFALL PATTERN FROM TODAY, WE BROUGHT THE LOWEST CONDITIONS TO KTTN. SATURDAY SHOULD BE MOSTLY VFR WITH A SOUTHERLY WIND AROUND 6 TO 10 KNOTS AND SCATTERED CUMULUS. SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED DURING THE AFTERNOON AND EARLY EVENING. HOWEVER, WE DO NOT HAVE ENOUGH FORECAST CONFIDENCE AT THIS TIME TO INCLUDE THEIR MENTION IN ANY OF OUR TAFS. OUTLOOK... SATURDAY NIGHT THROUGH SUNDAY...GENERALLY VFR /SMALL CHANCE FOR POCKETS OF STRATUS LATER SATURDAY NIGHT AND SUNDAY MORNING/, WITH ANY ISOLATED OR SCATTERED THUNDERSTORMS ENDING BY LATE SATURDAY EVENING. THEN, A BETTER CHANCE OF SOME SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON AND SUNDAY NIGHT AS A COLD FRONT SLOWLY ARRIVES. SOME OF THE STORMS MAY BE GUSTY ALONG WITH LOCAL SUB-VFR CONDITIONS FOR A TIME. A GENERAL SOUTH TO SOUTHWEST WIND SUNDAY AFTERNOON MAY GUST TO ABOUT 20 KNOTS. MONDAY AND TUESDAY...SOME SCATTERED SHOWERS OR THUNDERSTORMS MAY LINGER ESPECIALLY THROUGH MIDDAY MONDAY WITH LOCAL SUB-VFR POSSIBLE. OTHERWISE, VFR WITH ANOTHER LOW CHANCE OF A THUNDERSTORM TUESDAY AFTERNOON MAINLY SOUTH OF A LINE FROM KILG TO KACY. WEDNESDAY...A LOCAL SHOWER OR THUNDERSTORM IS POSSIBLE AS A SECONDARY COLD FRONT SLOWLY ARRIVES. && .MARINE... SEAS AND WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH SATURDAY. HOWEVER, WITH THE GRADIENT STARTING TO TIGHTEN UP, AN INCREASING SOUTHEASTERLY FLOW WILL DEVELOP TOWARD SATURDAY AFTERNOON AND EVENING, INCREASING WINDS AND SEAS SLIGHTLY. OUTLOOK... HIGH PRESSURE CENTERED TO OUR SOUTHEAST WILL ERODE SOME SUNDAY INTO MONDAY AS A COLD FRONT ARRIVES. A SOUTHERLY FLOW AHEAD OF THIS FRONT IS EXPECTED TO INCREASE SUNDAY INTO MONDAY AS THE PRESSURE GRADIENT TIGHTENS. THIS MAY RESULT IN ADVISORY LEVEL WIND GUSTS OCCURRING LATE SUNDAY AFTERNOON AND ESPECIALLY SUNDAY NIGHT. THESE WINDS ARE THEN EXPECTED TO DIMINISH MONDAY. THE INCREASED SOUTHERLY FLOW WILL ALSO BUILD THE SEAS, WHERE HEIGHTS MAY GET TO AROUND 5 FEET ON THE OCEAN SUNDAY NIGHT BEFORE GRADUALLY SUBSIDING MONDAY. SOME THUNDERSTORMS SUNDAY NIGHT MAY BE LOCALLY GUSTY ALONG WITH FREQUENT LIGHTNING. THE CONDITIONS ARE EXPECTED TO BE BELOW ADVISORY CRITERIA TUESDAY AND WEDNESDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ |
| #531630 (Received by flhurricane at: 10:14 PM 03.Aug.2012) AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 945 PM EDT FRI AUG 3 2012 .UPDATE...LOWERED CHANCE OF RAIN OVER LAND AREAS OVERNIGHT AS EARLIER CONVECTIVE ACTIVITY CONTRIBUTED TO STABILIZE THE LOCAL ATMOSPHERE. LATEST DOPPLER RADAR OBS SHOWS SOUTH FLORIDA VOID OF ANY PRECIPITATION. TROPICAL DISTURBANCE OVER THE NORTHERN BAHAMAS WILL CONTINUE TO SLOWLY MOVE WEST TONIGHT WITH SHOWERS AND THUNDERSTORMS GRADUALLY INCREASING OVER THE ATLANTIC WATERS AND THEN SPREADING WEST OVER THE EAST COAST AND EASTERN METRO AREAS TOWARD THE MORNING. MOST MODELS AGREE IN MOVING THIS SYSTEM ACROSS THE PENINSULA SATURDAY WITH NUMEROUS SHOWERS AND THUNDERSTORMS AFFECTING MOST AREAS SATURDAY AFTERNOON AND EVENING. LOCALLY HEAVY RAIN IS POSSIBLE AND MINOR FLOODING OF POORLY DRAINED AREAS AND ROADWAYS COULD OCCUR. THE NATIONAL HURRICANE CENTER IS MONITORING THIS SYSTEM FOR DEVELOPMENT, HOWEVER AT THIS TIME THERE IS ONLY A LOW CHANCE FOR DEVELOPMENT. RGH .AVIATION... LATEST SHORT TERM GUIDANCE KEEPS CONVECTION OFFSHORE THE ATLANTIC WATERS THROUGH THE NIGHT. AS A RESULT...SCT CLOUDS AND LIGHT EASTERLY WINDS SHOULD PREVAIL. SHRAS/TSRAS WILL BEGIN TO PUSH BACK INTO THE SOUTH FLORIDA PENINSULA BY LATE MORNING TOMORROW AS A TROUGH MOVES CLOSER TO THE AREA. THIS COMBINED WITH DIURNAL SEA BREEZE INTERACTIONS WILL ALLOW CONVECTION TO BE FAIRLY WIDESPREAD ACROSS SOUTH FLORIDA THROUGH MUCH OF THE DAY TOMORROW. && .PREV DISCUSSION... /ISSUED 259 PM EDT FRI AUG 3 2012/ SHORT TERM...(TONIGHT-MONDAY) THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING NORTH- NORTHEAST JUST EAST OF SOUTH FLORIDA TO THE NW BAHAMAS WITH MOST OF THE SHOWER/TSTM COVERAGE REMAINING AROUND THE TROUGH AXIS...INCLUDING OUR ADJACENT ATLANTIC WATERS. THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS SURFACE TROUGH JUST EAST OF THE LOCAL AREA AND GENERALLY INDICATES IT CONTINUING WESTWARD OVER SOUTH FLORIDA THROUGH THE DAY SATURDAY...POSSIBLY AS A WEAK LOW. AS A RESULT...WE WILL ADJUST THE RAINFALL CHANCES UP THROUGH THIS PERIOD OVER THE WEEKEND FROM WHAT WAS ADVERTISED IN THE PREVIOUS PACKAGE. THE NAM SOLUTION REMAINS THE OUTLIER AND INDICATES THIS FEATURE DEVELOPING A WELL DEFINED LOW-LEVEL CIRCULATION CENTER AND ADVANCING NW AND MOVING ASHORE ALONG THE EAST-CENTRAL PORTION OF THE FLORIDA PENINSULA LATER SATURDAY NIGHT. FOR THIS PACKAGE...WE WILL REMAIN CLOSER TO THE LATEST GFS/ECMWF SOLUTIONS AND GENERALLY SHOW IT CONTINUING WEST ACROSS THE AREA OVER THE WEEKEND. SUNDAY THROUGH MONDAY...MOIST SOUTHEAST FLOW WILL BE EXPECTED AS THE AFOREMENTIONED SURFACE TROUGH/UPPER LOW CONTINUES WEST AND AWAY FROM THE FL PENINSULA AND ERNESTO CONTINUES ITS WESTWARD TRACK ACROSS THE CARIBBEAN. MODERATE EASTERLY FLOW DUE TO AN ENHANCED GRADIENT BETWEEN ERNESTO TO THE SOUTH AND THE SUBTROPICAL RIDGE TO THE NORTH COMBINED WITH PRECIPITABLE WATER VALUES AROUND THE TWO INCH MARK WILL KEEP THE RAIN CHANCES IN THE FORECAST THROUGH THE PERIOD. LONG TERM...(MONDAY NIGHT-THURSDAY)... THE CHANCE OF RAIN TAPERS OFF FROM MIDWEEK ON AS THE ATLC HIGH CENTER MOVES WESTWARD PULLING SOME DRIER AIR OVER S FLA. A DEEP EASTERLY WIND FLOW DICTATES THAT THE HIGHER POPS WILL BE IN THE W INTERIOR AND W COAST. FORECASTED HURRICANE ERNESTO APPROACHES THE YUCATAN PENINSULA BY MID WEEK. AS ERNESTO TRACKS WESTWARD...AT THIS TIME...THE ONLY EFFECT TO S FLA WILL BE AN INCREASE IN THE LOW LEVEL EASTERLY WINDS FROM MIDWEEK ON. BUT KEEP AWARE OF NHC FORECASTS OF THE DEVELOPMENT AND FORECASTED MOVEMENT OF THIS STORM. MARINE... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE EXPECTED ACROSS THE ATLANTIC WATERS TONIGHT THROUGH SATURDAY AS A TROUGH OF LOW PRESSURE TRACKS WEST OVER THE AREA. WINDS AND SEAS WILL BE LOCALLY HIGHER IN AND AROUND THE HEAVIER SHOWERS AND STORMS THROUGH THIS TIME. EASTERLY WINDS ARE EXPECTED TO REACH THE MODERATE LEVELS INTO THE UPCOMING WEEK AS THIS TROUGH SHIFTS WEST OF THE MARINE AREAS AND TROPICAL STORM ERNESTO PASSES WELL SOUTH. FIRE WEATHER... NO CONCERNS THROUGH THE WEEKEND AND INTO THE UPCOMING WEEK AS PLENTY OF MOISTURE AND RAIN CHANCES REMAIN IN THE FORECAST. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 89 77 88 / 30 70 50 40 FORT LAUDERDALE 79 90 79 89 / 30 70 50 40 MIAMI 78 89 78 90 / 30 70 50 40 NAPLES 76 91 76 92 / 20 50 50 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ |
| #531629 (Received by flhurricane at: 9:59 PM 03.Aug.2012) AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 827 PM CDT FRI AUG 3 2012 .UPDATE... .SOUNDING DISCUSSION... LAUNCH DELAYED UNTIL 1830 LOCAL TIME DUE TO A COLLAPSING THUNDERSTORM NEARBY. OTHERWISE...NO PROBLEMS WITH THE FLIGHT THIS EVENING. A CONTINUED MOIST AND MODERATELY UNSTABLE SOUNDING WITH A PW OF 2.15 INCHES AND AN LI OF -4.7. EVEN WITH HIGH PW VALUES...MODERATELY DRY AIR IN PLACE IN THE LOWER TO MIDDLE LEVELS. A THICK BROKEN LAYER OF ALTOSTRATUS IN PLACE ABOVE 15,000 FEET ASL WHERE DEWPOINT DEPRESSIONS ARE BETWEEN 2 AND 5 DEGREES FAHRENHEIT. A LIGHT SOUTHWESTERLY FLOW IN THE LOWER LEVELS WITH A LIGHT TO MODERATE EASTERLY FLOW ABOVE 750 MB. && .PREV DISCUSSION... /ISSUED 407 PM CDT FRI AUG 3 2012/ SYNOPSIS... LATEST SURFACE ANALYSIS SHOWED A BROAD 1016MB HIGH OVER NORTHEAST GULF AND AN INVERTED TROUGH OVER THE BAHAMAS. UPPER LEVEL CHARTS AND SATELLITE REVEALED A HIGH OVER TEXAS AND ANOTHER HIGH OVER EASTERN ATLANTIC NEAR 70W...CREATING A SOMEWHAT COL FROM MISSISSIPPI TO FLORIDA. SOUNDING SHOWED INCREASE IN PW VALUE UP 2.15 INCHES FOR THIS MORNING...LIGHT SOUTHWEST FLOW 1000MB TO 800MB AND NORTHEAST TO NORTH FLOW 650MB TO 400MB. VAD WIND PROFILE CONTINUE TO SHOW THIS WIND PROFILE WITH STEERING WINDS PUSHING CONVECTION SLOWLY WESTWARD. WITH A FEW AREAS RECEIVING BRIEF DOWNPOURS...RELIEF HAS BEEN LIMITED WITH DEWPOINT READINGS CLIMBING UP TO NEAR 80 AT A FEW POINTS...ASD HOVERED AROUND 80 DEGREE DEWPOINT AFTER BRIEF SHOWER. ERGO...WILL LET HEAT ADV EXPIRE AT 7 PM THIS EVENING. DISCUSSION... UPPER LEVEL HIGH OVER TEXAS SHOULD REMAIN STATIONARY THROUGH SATURDAY. PRECIPITABLE WATER VALUE SHOULD REMAIN SLIGHTLY ABOVE 2 INCHES FOR TONIGHT AND SATURDAY. LOOKING FOR TEMPS TO DROP POSSIBLE 1 OF 2 DEGREES TONIGHT LOWER THAN THIS MORNING WITH DEWPOINT READINGS IN THE MID 70S. IN ADDITION...TEMPS AND HEAT INDEX VALUE WILL APPROACH 100F BY 11 AM SATURDAY. HOWEVER...SCATTERED CLOUDS THEN CONVECTION WILL DISTURB DANGEROUS HEAT INDEX VALUES THROUGHOUT THE DAY. WILL ALLOW HEAT ADVISORY TO EXPIRE THIS EVENING WITH THE INCREASE RAIN CHANCES. THE SURFACE FEATURE ASSOCIATED WITH AREA OF DISTURBED WEATHER OVER BAHAMAS WILL MOVE ACROSS FLORIDA OVER THE WEEKEND AND APPROACH NORTH CENTRAL GULF BY MONDAY. UPPER LEVEL WINDS ARE EXPECTED TO WEAKEN OVER FLORIDA BUT THE PENINSULA WILL HAMPER DEVELOPMENT THROUGH THE WEEKEND AND NEXT WEEK. WILL INCREASE RAIN CHANCES FOR MONDAY WITH SURFACE FEATURE REMAINING AN INVERTED TROUGH NEXT MONDAY FOR NOW. GFS...ECMWF AND NHC KEEP EARNESTO WELL SOUTH 22N THROUGH NEXT 5 DAYS AND HPC KEEPS EARNEST SOUTH OF 23N THROUGH NEXT 7 DAYS. FOR NOW...UPPER LEVEL HIGH WILL SLOWLY RETREAT OVER ROCKIES AND CENTRAL PLAINS TUESDAY THROUGH FRIDAY. THIS WILL ALLOW UPPER FLOW TO PUSH SOUTH TO APPROACH THE FORECAST AREA THURSDAY INTO FRIDAY. MOISTURE AXIS MAY POOL OVER THE AREA...THIS WILL MAINTAIN RAIN CHANCES AROUND 30 PERCENT DAY 5 THROUGH DAY 7 AVIATION... VFR CONDITIONS WILL PREVAIL OUTSIDE OF ANY CONVECTION THROUGH THE REMAINDER OF THE AFTN AND EVNG HRS. BEST CHANCE FOR CONVECTION WILL BE ALONG THE ERN HALF OF THE CWA MAINLY TERMINALS EAST OF THE I-55 CORRIDOR. ONCE SHRA/TSRA DISSIPATE LOOK FOR VFR CONDITIONS THROUGH THE NIGHT. ONLY ISSUE COULD BE THE TYPICAL PROBLEM SITES THAT SEE MVFR VISBIES DURING THE EARLY MORNING HRS. /CAB/ MARINE... A BROAD RIDGE OF HIGH PRESSURE ACROSS THE NORTH GULF WILL PERSIST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. AN AREA OF DISTURBED WEATHER WILL TRACK ACROSS FLORIDA OVER THE WEEKEND AND MOVE ACROSS THE NORTH CENTRAL GULF OF MEXICO. THIS FEATURE WILL INCREASE RAIN CHANCES OVER THE COASTAL WATERS MONDAY THROUGH THURSDAY. GENERALLY LIGHT AND SOMEWHAT VARIABLE FLOW ACROSS THE COASTAL WATERS THROUGH SUNDAY. A NORTH WINDS MAY OCCUR AS THE WAVE APPROACHES THE COASTAL WATERS MONDAY. WINDS WILL RETURN TO LIGHT SOUTHERLY TUESDAY AND WEDNESDAY WITH MAINLY BE 10 KNOTS OR LESS AND SEAS 2 FEET OR LESS. 18 && .PRELIMINARY POINT TEMPS/POPS... MCB 74 93 74 94 / 10 40 20 40 BTR 76 95 76 94 / 10 30 20 40 ASD 75 93 76 92 / 10 40 20 40 MSY 79 92 80 93 / 10 40 20 40 GPT 76 93 76 94 / 20 40 20 40 PQL 74 93 74 94 / 20 40 20 40 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$ |
| #531628 (Received by flhurricane at: 9:53 PM 03.Aug.2012) AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 943 PM EDT Fri Aug 3 2012 .NEAR TERM [Through Tonight (Updated as of 0115z)]... Convection has quieted down now across the Tri-State region, with only a few sprinkles possible across southeast Alabama and the eastern panhandle of Florida over the next hour. Nocturnal showers and thunderstorms will form along old boundaries and in the convergent flow regime primarily west of Apalachicola. Isolated waterspouts will be possible in the morning, especially nearshore. The only other threat worth mentioning is the chance for fog and low cloud development near dawn. Expect fog to be the most dense in locations that received rain this afternoon. More on this can be found in the aviation discussion. && .SHORT TERM [Saturday Through Sunday Night]... The main feature of concern over the short-range period will be the tropical wave currently situated over the northern Bahamas. This feature is expected to move west across the FL Peninsula tonight into Saturday and then across the eastern Gulf of Mexico from Sunday into Monday. The NAM continues to want to develop a tropical cyclone as early as tonight. This is on the deep end of the spectrum of solutions as is still not accepted. We favor a solution similar to a GFS/ECMWF blend which maintains an open wave as the system crosses FL and the Gulf. For Saturday, we will not quite yet be feeling any impacts from the tropical wave. Instead, a short wave currently over the TN Valley will drop down the east side of the large Southern Plains ridge and enhance PoPs across our zones, particularly out west. Most of the area is getting a likely PoP. By Sunday, the wave will begin pulling in deep tropical moisture into the area from the southeast. Likely PoPs are forecast for the southeastern half of the forecast area. Temps will generally run a degree or two above normal. Eastern areas will be a couple of degrees cooler on Sunday due to abundant cloud cover and numerous showers. && .LONG TERM [Monday through Friday]... Weak tropical wave axis is forecast to pass across the forecast area late Sunday into Monday. With the southeasterly flow in the wake of the wave and a weakness aloft between subtropical ridges to the east and west, expect deep layer moisture to remain elevated on Monday with at least scattered showers and thunderstorms across the entire forecast area. The onshore low-level flow trajectory is expected to continue through at least Thursday, keeping PoPs elevated and temperatures near seasonal norms. && .AVIATION [Beginning 01Z Saturday]... With the convection basically over for the night at the terminals, it will once again be a difficult Taf Package for determining restrictions for the overnight and early morning hours. Since the most of rain fell earlier in the day on Friday (at the sites which did receive rain), do not expect any sites to bottom out. So, leaned towards the NARRE solution of Low Cigs vs. Low Vis. Went with MVFR conditions at all terminals except DHN with IFR Cigs. && .MARINE... A ridge of high pressure south of the area is expected to shift north as a tropical wave over the Bahamas approaches from the east. This wave is expected to cross the FL Peninsula tonight into Saturday and then move westward across the eastern Gulf of Mexico from Sunday into Monday. This system will back winds to the east and possibly northeast from Saturday into Sunday night. At this point, the wave is not forecast to develop into a tropical cyclone and we keep winds 15 knots or less. However, interests in the eastern Gulf of Mexico should monitor the latest outlooks from the National Hurricane Center on this feature over the weekend. Once the wave moves away into the central gulf, the ridge will re-establish itself over the area swinging winds back to onshore. && .FIRE WEATHER... Afternoon Relative Humidity levels are expected to remain above critical thresholds for the next week, so red flag conditions are not expected. && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ |
| #531627 (Received by flhurricane at: 9:53 PM 03.Aug.2012) AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 852 PM EDT FRI AUG 3 2012 .UPDATE...CONVECTION PEAKED OVER INTERIOR AS SEABREEZES COLLIDED LATE THIS AFTERNOON. THUNDERSTORMS STILL LINGER OVER INLAND SE GA AS OUTFLOWS WORK ON MOIST UNSTABLE AIRMASS. WILL DELETE POPS OVER NE FL AND KEEP SMALL POP FOR INLAND SE GA TIL MIDNIGHT. MAY SEE AN INCREASE IN SHOWERS LATE TONIGHT OVER THE COASTAL WATERS AS TROPICAL WAVE OVER THE BAHAMAS MOVE TOWARDS FLORIDAS EAST COAST. SOME MODELS HINT AT WEAK SURFACE LOW DEVELOPMENT WITH THIS SYSTEM SO WILL BE MONITORING FOR THAT SMALL POSSIBILITY. && .AVIATION...CONVECTION HAS ENDED NEAR TAFS SITES AND EXPECT VFR CONDITIONS TONIGHT. && .MARINE...SE FLOW OVER THE WATERS WITH WINDS UP TO 15 KNOTS OFFSHORE. SHOWERS MAY INCREASE LATE TONIGHT AS TROPICAL WAVE APPROACHES. RIP CURRENTS: LOW RISK ON SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 71 93 72 92 / 20 40 20 50 SSI 77 87 79 88 / 20 30 40 50 JAX 73 91 76 89 / 20 30 30 60 SGJ 75 89 79 87 / 20 30 40 60 GNV 70 92 73 89 / 20 40 30 70 OCF 71 92 74 89 / 20 40 30 70 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ |
| #531626 (Received by flhurricane at: 9:53 PM 03.Aug.2012) AFDTBW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL 939 PM EDT FRI AUG 3 2012 .DISCUSSION... AFTERNOON SHOWERS AND STORMS HAVE ENDED ACROSS THE AREA. ACTIVITY SHOULD REDEVELOP OVER THE COASTAL WATERS OVERNIGHT SO HAVE ISOLATED CHANCES CONTINUING THERE...BUT HAVE UPDATED THE ZONES TO REMOVE RAIN CHANCES. TEMPS ARE ON TRACK TO FALL TO AROUND 70 INLAND TO THE MID 70S ALONG THE COAST. SHOWER AND THUNDERSTORM ACTIVITY SHOULD INCREASE FOR TOMORROW AND SUNDAY AS A TROPICAL WAVE MOVES OVER THE AREA AND ENHANCES DIURNAL STORMS. MAY HAVE A FEW SEVERE STORMS WITH GUSTY WINDS BEING THE MAIN THREAT. && .AVIATION... VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE TAF FORECAST PERIOD. SCATTERED THUNDERSTORMS ARE EXPECTED AS THE GULF SEA BREEZE PUSHES INLAND AND MEETS UP WITH THE ATLANTIC SEA BREEZE LATE SATURDAY AFTERNOON OR EARLY SATURDAY EVENING. FOR NOW WILL MENTION VCTS AT ALL TERMINALS...STARTING AT 18Z FOR KLAL AND AT 20Z FOR ALL OTHER TERMINALS. && .MARINE... BUOYS SHOWING GENERALLY E/SE FLOW AT 5 TO 10 KNOTS IN PLACE ACROSS THE COASTAL WATERS WITH SEAS LESS THAN 2 FEET. CURRENT FORECAST IS ON TRACK WITH SOME ISOLATED THUNDERSTORMS POSSIBLE OVERNIGHT. NO MAJOR CHANGES FOR THE UPDATE. && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ |
| #531625 (Received by flhurricane at: 9:48 PM 03.Aug.2012) AFDMOB AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE MOBILE AL 712 PM CDT FRI AUG 3 2012 .UPDATE...CURRENTLY PREPARING AN UPDATE TO THE OVERNIGHT FORECAST TO TRIM POPS A CATEGORY (DOWN INTO SLIGHT CHANCE) AFTER 06Z...BUT KEEPING POPS GOING AGAIN FOR TOMORROW AS THE NEXT MINOR SHORTWAVE MOVES DOWN THE NORTHERLY FLOW ALOFT INTO THE AREA. STILL GETTING OCCASIONAL LIGHTNING STRIKES DOWNSTREAM OF WEAKENING STORMS SO WILL KEEP BETTER CHANCES OF THUNDER GOING NORTH OF THE COAST UNTIL 03Z. /05 .AVIATION...KEPT VCTS GOING FOR KMOB GIVEN OCCASIONAL CLOUD TO GROUND STRIKES IN THE VICINITY FROM UPPER CLOUD SPREADING SOUTH FROM DECAYING STORMS OVER NORTH MOBILE COUNTY. OTHERWISE...MENTIONED 5SM IN LIGHT FOG TONIGHT AT KMOB AND KEPT KPNS AND KBFM IN VFR CATEGORY THROUGH MORNING WITH JUST SOME LINGERING HIGH LEVEL CLOUD DEBRIS FROM EARLY EVENING STORMS OVER THE INLAND AREAS. WILL SEE MORE SCATTERED TSRA AROUND THE AREA TOMORROW SO PUT IN VCTS AFTER 17Z WITH A TEMPO MENTION OF 2SM TSRA FOR KPNS GIVEN GREATER CHANCE OF SEEING STORMS OVER THE PANHANDLE TOMORROW AFTERNOON. /05 **********PREV DISCUSSION...ISSUED 331 PM CDT FRI AUG 3 2012******* .SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...CHART FEATURES SHOW A STATIONARY FRONT IS ANALYZED MEANDERING THROUGH THE SOUTHEAST STATES, SUPPORTED BY AN UPPER TROUGH WITH A STRONG VORTLOBE FORECAST TO PASS INTO THE CWA AROUND SUNSET. BELIEVE EXTENSION OF SEVERE THUNDERSTORM WATCH IS UNLIKELY DUE TO LOSS OF HEATING WHEN THAT FEATURE ARRIVES. WATER VAPOR IMAGERY INDICATES THE GFS INITIALIZED WELL ON THE POSITION OF SAID FEATURE... WATER VAPOR IMAGERY INDICATES ANTICYCLONIC TURNING IN THE 700 TO 300 MB LAYER AND THE IR SHOWS COOLING TOPS FROM A NUMBER OF MCS`S IN THE REGION DOWN TO -72 C WELL NORTH AND -60 TO -65 IN SMALLER FEATURES OVER NORTH ESCAMBIA AND NORTH CENTRAL BALDWIN COUNTIES AS OF MID AFTERNOON. RADAR DATA INDICATE THESE HAVE STRONG UPDRAFTS IN WHICH 50 DBZ CORES ARE TOUCHING OR GOING A BIT PAST -20C. WIND GUSTS ABOVE 60 MPH ARE POSSIBLE UNTIL AROUND SUNSET. WE BELIEVE SATURDAY WILL SHOW A LESSER RISK OF MICROBURSTS THAN TODAY DESPITE HIGHER POPS CALCULATED. AS FOR MODEL OUTPUTS, PRECIPITABLE WATER IN NAM AND GFS AROUND 2 TO 2.2 INCHES. INSTABILITY A LITTLE MORE SUBDUED THAN TODAY...ABOUT 2000 TO 2400 FOR THE CAPE AND -4 FOR LI. MID LEVEL VORTLOBES MOVING IN FROM THE OHIO VALLEY SOUTHWARD OVER THE REGION WILL SHOVE THE LAYER UPWARD ENOUGH TO FORCE SOME CONVECTION. GIVEN LITTLE TO NO CHANGE...THE GFS OUTPUT SEEMS PLAUSIBLE SO WE STUCK WITH IT. WRF ARW EAST SHOWS CONVECTIVE INITIATION TO BEGIN ALONG THE COAST ABOUT MIDMORNING. THE HRRR DOES NOT FORECAST OUT FAR ENOUGH SO WE CANNOT COMPARE.. IN ANY CASE A FEW OF THE THUNDERSTORMS SATURDAY CAN BRING STRONG GUSTY WINDS TO 45 MPH FREQUENT LIGHTNING...LOCALLY HEAVY RAIN AND SMALL HAIL. ONE OR TWO COULD ALSO INTENSIFY BRIEFLY TO SEVERE CRITERIA WITH WINDS OVER 60 MPH AND HAIL TO AROUND QUARTER SIZE. STORM MOTION EXPECTED TO BE A DRIFT TO THE SOUTH 5 TO 10 MPH. BEFORE THE ONSET OF STORMS...HIGHS INTO THE MID 90S OVER THE INTERIOR AND CLOSER TO 90 ALONG THE COAST. TONIGHT`S LOWS IN THE LOWER/MID 70S. FOR SUNDAY WE ARE EXPECTING TO SEE VORTLOBES ALONG THE EASTERN EDGE OF THE UPPER HIGH IN THE SOUTHERN PLAINS AND APPROACH FROM THE NORTH. IT WILL BE A DIURNAL RHYTHM OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE WEEKEND DURING THE DAY AND BECOMING ISOLATED OVERNIGHT. HIGH TEMPERATURES BOTH DAYS WILL REMAIN NEAR NORMAL...MID 90S AND WITH RH AROUND 60 PERCENT...HEAT INDICES WILL BE CLOSE TO THAT. HIGHEST AFTERNOON HEAT INDICES WILL RANGE FROM 96 TO 101 DEGREES. LOWS BOTH NIGHTS WILL BE IN THE LOWER TO MID 70S INLAND AREAS...WITH UPPER 70S ALONG THE BEACHES. ON TROPICAL STORM ERNESTO...THE OFFICIAL NHC FORECAST TRACK CONTINUES MOVING THE SYSTEM THROUGH CARIBBEAN SEA THIS WEEKEND AND INTENSIFYING INTO A HURRICANE SOUTH OF JAMAICA LATE SUNDAY. INTENSIFICATION OF ERNESTO AS FORECAST IS LARGELY ATTRIBUTED TO THE SYSTEM MOVING INTO AN AREA OF VERY LOW WIND SHEAR AND OVER SEA SURFACE TEMPERATURES IN THE LOW 80S. /77 && .LONG TERM [MONDAY THROUGH THURSDAY]...ERNESTO IS FORECAST TO CONTINUE TO TRACK ABOUT 280 TO 290 DEGREES REACHING SOUTH OF THE TIP OF THE YUCATAN PENINSULA EARLY WEDNESDAY. ELSEWHERE THE UPPER SADDLE POINT WILL REMAIN OVER THE FORECAST AREA THROUGHOUT THE LONG TERM. SEABREEZE DRIVEN CONVECTION WILL PERSIST THROUGH THE LONG TERM...IN A DIURNAL CYCLE OF SCATTERED SHOWERS AND THUNDERSTORMS EACH DAY AS VORTLOBES CONTINUE TO MOVE OVER THE FORECAST AREA. HIGHS EACH DAY FROM 90 TO 95 DEGREES. HIGHEST HEAT INDICES WILL RISE SLOWLY TO 96 TO 101 DEGREES BY NEXT WEEKEND. LOWS EACH NIGHT THROUGH THE ENTIRE LONG TERM WILL BE IN THE LOWER TO MID 70S INLAND AREAS...WITH UPPER 70S ALONG THE BEACHES. /77 && .AVIATION (03.18Z ISSUANCE)...SCATTERED TSRA WILL CONTINUE TO INCREASE AROUND THE TERMINALS THROUGH THE AFTERNOON. THE CONVECTION WILL DISSIPATE THIS EVENING FOLLOWED BY MORE DEVELOPMENT SATURDAY MORNING. /13 && .MARINE...SURFACE HIGH PRESSURE OVER THE SOUTHWEST ATLANTIC NOSES WESTWARD INTO THE GULF THROUGH THE EARLY HALF OF NEXT WEEK. THIS WILL MAINTAIN A GENERAL LIGHT ONSHORE FLOW WITH SEA HEIGHTS 2 FEET OR LESS. WINDS...WAVES AND SEAS LOCALLY HIGHER NEAR STORMS. /13 && .FIRE WEATHER...WITH A SURFACE HIGH OVER THE WESTERN ATLANTIC AND ANOTHER OVER TEXAS...LIGHT SOUTH WINDS WILL CONTINUE THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND THUNDERSTORMS EACH MORNING BECOMING MORE NUMEROUS EACH AFTERNOON. TRANSPORT WINDS TO REMAIN LIGHT...ACTUALLY WEAKER THAN SURFACE WINDS SINCE THERE IS AN UPPER TROUGH OVER THE NORTHEASTERN STATES CAUSING WIND TO REVERSE DIRECTION AT ABOUT 4000 TO 5000 FEET. MIXING HEIGHTS WILL BE JUST DEEP ENOUGH TO BRING SOME DISPERSION IN THE DAYTIME...ALBEIT IN THE 20S AND 30S. /77 && .PRELIMINARY POINT TEMPS/POPS... MOBILE 75 92 73 94 / 30 50 30 40 PENSACOLA 77 92 75 93 / 30 40 30 30 DESTIN 78 91 78 91 / 30 40 30 40 EVERGREEN 74 93 71 95 / 40 50 40 40 WAYNESBORO 74 93 72 95 / 30 60 40 40 CAMDEN 75 94 72 95 / 40 70 50 40 CRESTVIEW 71 93 70 94 / 30 40 30 40 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$ |
| #531624 (Received by flhurricane at: 9:36 PM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 842 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE SOUTHEAST COAST WILL ALLOW FOR WARM AND HUMID CONDITIONS ACROSS THE AREA THROUGH THE WEEKEND. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL ALSO CONTINUE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH THE REGION ON MONDAY RESULTING IN BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... LATEST SATELLITE TRENDS SHOW EXPANDING CU FIELD ACROSS NC/VA AS MOST ORGANIZED ACTIVITY REMAINS CLOSE TO MID LEVEL SHORTWAVE IN KY/TN AND UPPER LEVEL LOW IN SE NC. FEW TOWERS ATTEMPTED TO GO UP JUST SOUTH OF RICHMOND...BUT WARMING ALOFT HAS REALLY LIMITED UPDRAFT STRENGTH THUS FAR. 700MB THETA E RIDGE SET UP ACROSS SE VA/NE NC WITH OBSERVED DEWPOINTS INCREASING INTO THE LOW 70S. LATEST BLENDED PRECIP WATERS HAVE INCREASED TO 1.5 TO 1.6 INCHES. WITH THAT SAID...SUFFICIENT LOW LEVEL MOISTURE EXIST FOR AFTERNOON CONVECTION. THE LIMITING FACTORS SO FAR TODAY HAVE BEEN WARMING ALOFT (REDUCING MID LEVEL LAPSE RATES) WITH 500MB TEMPS PROGGED AROUND 6-7C...AND DRY MID TO UPPER LEVELS...500MB RH AT 20 PCT. MIXED LAYER CAPE INCREASES OF AROUND 1000 J/KG OVER THE PAST 3 HOURS TO AROUND 2000 J/KG SHOULD INITIATE DECENT UPDRAFTS ACROSS THE AREA. LATEST MODEL SOLUTIONS HAVE STRUGGLED HANDLING AFTERNOON CONVECTION SO HAVE OPTED TO LEAVE CURRENT SCATTERED POPS FOR THIS AFTERNOON ALONE. DUE TO WEAK FLOW/SHEAR...LOCALLY HEAVY RAINFALL WILL AGAIN BE POSSIBLE. STORM MERGERS AND STEEP LOW LEVEL LAPSE RATES WILL ALSO PROVIDE THE POSSIBILITY OF LOCALIZED STRONG GUSTY WINDS. LOSS OF DAYTIME HEATING WILL ALLOW FOR A RAPID DECREASE IN COVERAGE THIS EVENING. AFTERNOON TEMPERATURES HAVE REACHED INTO THE UPPER 80S NEAR THE COASTS TO LOW 90S ELSEWHERE. LOCAL HEAT INDICES IN MID/UPPER 90S WITH A FEW LOCALIZED 100 DEG READINGS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... SHORTWAVE TROUGH TO LIFT NE SATURDAY WITH BERMUDA HI PRESSURE EXPANDING WESTWARD. SWLY FLOW ALOFT WILL ALLOW FOR CONTINUED HUMID CONDITIONS WITH ABOVE NORMAL DAYTIME TEMPERATURES. A STRONG MID LEVEL SHORTWAVE WILL APPROACH THE GREAT LAKES REGION THROUGH THE WEEKEND. WEAK MID LEVEL DISTURBANCES WILL COMBINE WITH THE WARM AND HUMID AIRMASS TO PROVIDE ISOLATED/SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. TEMPERATURES THIS WEEKEND WILL RANGE FROM THE UPPER 80S TO LOW/MID 90S UNDER MOSTLY SUNNY TO PARTLY CLOUDY SKIES. HEAT INDICES EXPECTED TO REMAIN BELOW HEAT ADVISORY CRITERIA. A COLD FRONT IS PROGGED TO REACH CENTRAL VA BY MONDAY MORNING/AFTERNOON RESULTING IN MORE ORGANIZED AND WIDESPREAD CONVECTION MONDAY AFTERNOON. ATTM...GFS/ECMWF SOLUTIONS TEND TO BE MORE PROGRESSIVE/DEEPER WITH SFC TROUGH MONDAY THAN NAM/SREF SOLUTIONS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... WE HAVE ARRIVED AT THE TIME OF YEAR WHERE FRONTS HAVE A TUFF TIME MOVING SOUTH OF THE REGION DUE TO THE STRENGTH OF THE BERMUDA HIGH. NEXT WEEK WILL FEATURE ONE SUCH BOUNDARY THAT STALLS AND WEAKENS ACROSS THE REGION BY TUESDAY...LINGERS AS A LEE TROF WEDNESDAY AND THURSDAY WITH ANOTHER FRONTAL BOUNDARY APPROACHING FROM THE NORTH FRIDAY. RESULT WILL BE A TRIGGER FOR CHC POPS EACH DAY...CONCENTRATING ON THE AFTERNOON/EVENING HOURS. BEST MOISTURE AND HIGHEST POPS SEEN MONDAY NIGHT THROUGH WEDNESDAY. SLGHT CHC POPS THURSDAY EXCEPT CHC ACROSS THE SE. SLGHT CHC FRI FOR NOW. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... STRONG BERMUDA HIGH OVER THE ATLANTIC KEEPING SOUTHERLY FLOW ACROSS THE REGION. WIDELY SCATTERED CONVECTION MOSTLY WEST AND NORTH OF OF OUR REGION WILL PROBLY DIE BY AROUND 10 PM OR SOONER. GUIDANCE INDICATES WNDS AT 4-8 KTS OVERNIGHT. SOME PTCHY FOG WILL OCCUR BUT SHOULD NOT ADVERSELY AFFECT TAF LOCATIONS. HOWEVER WOULD NOT BE SURPRISED TO SEE SHORT PERIOD OF 2-3 MI VIS AT SBY/PHF/ECG DURING EARLY MORNING. LITTLE CHANGE IN THE PATTERN IS EXPECTED FOR SAT AND SUN WITH ISOLATED TO SCATTERED AFTN/EVENING TSTMS PSBL THRU THE WEEKEND. THERE WILL BE AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... NO FLAGS AS SRLY FLOW ARND BERMUDA HIGH PRESSURE DOMINATES THROUGH THE WEEKEND. SOME CHANELLING UP THE BAY TONIGHT AND SAT NIGHT WILL KEEP WINDS BTWN 10-15 KTS. INCRG PRESSURE GRADIENT AHEAD OF APPRCHG BOUNDARY/TROF MAY RESULT IN MINIMAL SCA CONDITIONS SUN NIGHT / MON. BOUNDARY STALLS/WEAKENS OVER THE REGION EARLY NEXT WEEK WITH SW FLOW CONTINUING. && .EQUIPMENT... KDOX RADAR HAS RETURNED TO NORMAL OPERATIONS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...SAM |
| #531623 (Received by flhurricane at: 9:36 PM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 808 PM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH SATURDAY/... AS OF 8 PM FRIDAY...LOSS OF DAYTIME HEATING HAS LEAD TO A CESSATION OF CONVECTION FOR THE EVENING. CANNOT RULE OUT THE SPOT SHOWER INLAND OVERNIGHT...CONSIDERING RESIDUAL BOUNDARIES AND ONGOING STRONG CONVECTION OVER THE FOOTHILLS OF CENTRAL NC AND SC. HOWEVER...NO LONGER ANY UPPER SUPPORT FOR STRONG STORMS OVER OUR AREA. RADAR LOOPS SHOW SHOWERS WELL OFFSHORE GRADUALLY APPROACHING THE COAST. THESE APPEAR TO BE OUTRIDERS OF A WEAK TROPICAL WAVE EXTENDING NNE FROM THE VIRGIN ISLANDS. DO NOT EXPECT THESE WILL MAKE IT ASHORE DURING THE NEAR TERM AS THEY ARE DISSIPATING AS THEY APPROACH THE COAST. COULD SEE SOME PATCHY FOG OVERNIGHT WHERE WE HAD APPRECIABLE RAINFALL TODAY. LITTLE CHANGE IN MINIMUM TEMPERATURES FROM RECENT DAYS...EXPECT LOWER TO MID 70S MOST LOCATIONS. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...AMPLIFICATION OF THE BERMUDA RIDGE WILL BRING SUBSIDENT DRYING ALOFT TO THE REGION SATURDAY...WHICH WILL LIKELY SQUELCH TSTMS INTO AN ISOLATED CATEGORY. LOW-LEVEL MOISTURE WILL LINGER ACROSS THE EASTERN CAROLINAS IN SOUTHERLY MOIST FLOW TO 700 MB. SURFACE HEATING AND THE SEA BREEZE FRONT SHOULD INTERACT WITH THIS MOISTURE TO PRODUCE ISOLATED AFTERNOON CONVECTION. IT IS NOT COMPLETELY CLEAR IF THE DRYNESS COULD RESULT ONLY IN SHRA AS OPPOSED TO TSTMS...BUT HAVE INCLUDED THUNDER DUE TO STRONG SFC HEATING. SUNDAY IS INTERESTING...IN THAT MOISTURE DEEPENS AND A WEAK TROPICAL WAVES MOVES INTO FLORIDA...ADVERTISING COASTAL SHOWERS ENCROACHING MAINLY SOUTH CAROLINA. HAVE RAISED POP VALUES SUNDAY BUT DUE TO THE UNCERTAINTY OF THE TROPICAL WAVES NORTHERN INFLUENCE...HAVE HELD POP VALUES IN THE ISOLATED TO SCATTERED CATEGORY SUNDAY. BOTH DAYS WILL BE SIMILAR IN TEMPERATURE...BUT SATURDAY COULD BE A FEW DEGREES WARMER DUE TO LESS CLOUDS AND MORE COLUMN SUBSIDENCE. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...LACK OF ANY SIGNIFICANT 5H TROUGH COMBINED WITH WEAK RIDGING AT THE SURFACE AND ALOFT WILL KEEP A WEAK COLD FRONT STALLED NORTHWEST OF THE REGION FOR MUCH OF THE PERIOD. DURING THE MIDDLE OF NEXT WEEK A SHORTWAVE TROUGH WILL REINFORCE THE 5H TROUGH...PUSHING WHAT IS LEFT OF THE STALLED BOUNDARY TO THE COAST LATE NEXT WEEK. FOR THE FIRST HALF OF THE PERIOD THE BERMUDA HIGH AND STALLED FRONT WILL PRODUCE THE TYPICAL SUMMER PATTERN WITH SEA BREEZE CONVECTION AND STALLED FRONT THE INITIAL FOCUS FOR CONVECTION. RESULTING OUTFLOW BOUNDARIES WILL GENERATE ADDITIONAL STORMS...BUT GIVEN SOME MID LEVEL SUBSIDENCE DO NOT THINK COVERAGE WILL BE ABOVE 30 TO 40...SIMILAR TO CLIMO. LATE IN THE PERIOD TROUGHING ALOFT HELPS PUSH REMAINS OF FRONT TO THE COAST. TROUGH AXIS WEST OF THE AREA LEADS TO DEEP SOUTHWEST FLOW...TAPPING GULF MOISTURE. POP REMAINS IN THE CHANCE REALM THROUGH THE END OF THE PERIOD GIVEN LOW LEVEL CONVERGENCE AND PRECIPITABLE WATER VALUES OVER 2 INCHES. TEMPERATURES WILL BE WITHIN A FEW DEGREES OF CLIMO THROUGH THE PERIOD...UPPER 80S TO LOW 90S AND LOW TO MID 70S. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AS OF 00Z...VFR CONDITIONS EXPECTED THIS EVNG. MVFR VSBYS IN BR WILL DEVELOP 08Z-12Z AT FLO/LBT TERMINALS...WITH TEMPO MVFR VSBYS AT THE ILM TERMINAL. THERE IS ONLY MDT CONFIDENCE OF IFR VSBYS AT FLO/LBT 09-12Z. VSBYS AT CRE/MYR THE VSBYS SHOULD REMAIN VFR OVERNIGHT BUT A TEMPO MVFR CEILING IS PSBL AT ANY COASTAL TERMINALS 08-12Z. VFR EXPECTED AFTER SUNRISE. THE PROB OF THUNDERSTORMS IS LOW SAT THUS WILL NOT MENTION IN TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 8 PM FRIDAY...LATEST OBS SHOW SOUTHERLY WINDS OF 10 TO 15 KTS WITH SEAS OF 2 TO 3 FT OVER THE WATERS THIS EVENING. SOUTHERLY WINDS WILL CONTINUE THROUGH THE PERIOD. THE 2 TO 3 FT SEAS CURRENTLY WIDESPREAD ACROSS THE WATERS WILL REMAIN UNCHANGED THROUGH THE OVERNIGHT PERIOD...WITH AN AVERAGE PERIOD OF ABOUT 9 SECONDS. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...S-SSE WINDS EXPECTED SATURDAY AND SUNDAY...AND INCREASING A BIT INTO SUNDAY. THIS FETCH WILL BUILD SEAS FROM 2-3 FT MUCH OF SATURDAY...TO 3-4 FEET SATURDAY NIGHT INTO SUNDAY AS SSE WINDS INCREASE TO AROUND 15 KNOTS BY SATURDAY EVENING. SEAS WILL BE A MIX OF SSE WAVES WITH MIXED WAVE PERIODS OF 6 SECONDS AND 10 SECONDS. STORMS WILL BE ISOLATED SATURDAY...AND MAINLY OVER LAND. BY SUNDAY...INCREASING SHOWERS AND TSTMS OVER THE WATERS MAY BE EXPECTED AS A TROPICAL WAVE MOVES INTO NORTH FLORIDA. THIS ACTIVITY WILL BE FAVORED OVER THE SC WATERS IN CLOSER PROXIMITY TO THE WAVE. NO SMALL CRAFT ADVISORIES ARE EXPECTED THIS WEEKEND. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 3 PM FRIDAY...BERMUDA HIGH AND STALLED DISSIPATING FRONT ACROSS THE CENTRAL CAROLINAS WILL KEEP SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. EARLY ON...THE GRADIENT WILL BE ILL-DEFINED KEEPING SPEEDS ON THE LOW END OF THE 10 TO 15 KT RANGE. SLIGHT PINCHING OF THE GRADIENT LATE IN THE PERIOD WILL LEAD TO A MARGINAL INCREASE IN SPEEDS...THOUGH WINDS SHOULD REMAIN IN THE 10 TO 15 KT RANGE. SEAS WILL RANGE FROM 2 TO 3 FT FOR MUCH OF THE PERIOD WITH SOME ISOLATED 4 FT POSSIBLE WELL OFF CAPE FEAR. && .TIDES/COASTAL FLOODING... TIDAL DEPARTURES ABOUT NORMAL THIS EVENING. CONSIDERING THAT WE JUST BARELY MET COASTAL FLOOD ADVISORY CRITERIA LAST NIGHT...DO NOT THINK THAT WE WILL MEET IT THIS TIME. NO ADVISORIES PLANNED FOR THE NEAR TERM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531622 (Received by flhurricane at: 9:36 PM 03.Aug.2012) AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 923 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL CROSS THE GREAT LAKES SUNDAY...BEFORE MOVING THROUGH SUNDAY NIGHT. WEAK HIGH PRESSURE WILL MOVE OVER THE MID-ATLANTIC REGION FOR THE FIRST PART OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... SIMILAR TO LAST EVENING...MOST OF THE SHOWERS AND THUNDERSTORMS HAVE DISSIPATED WITH THE SETTING OF THE SUN BUT A COUPLE OF ISOLATED CELLS REMAIN AT 01Z. THESE WILL LIKELY ALSO DISSIPATE WITHIN THE NEXT COUPLE OF HOURS ALTHOUGH THE HRRR SUGGESTS THAT AN ISOLATED SHOWER STILL CAN/T BE RULED OUT TOWARD THE HIGHLANDS/SHENANDOAH VALLEY AREA OVERNIGHT. MID-CLOUDS MAY THIN OUT/SCATTER OVERNIGHT...SO PATCHY FOG MAY ALSO FORM LATER TONIGHT. TMRW WL BE A TYPICAL ERLY AUG DAY..IN FACT QUITE A BIT LK TDA. LGT FOG WL BECOME HZ...HZ WL BECOME AFTN CU. ONCE AGN THE MTNS WL BE THE BEST PLACE FOR AFTN CNVCTN TO FORM. HIGH TEMPS AGN XPCTD TO RANGE FM THE U80S TO THE M90S. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... DIURNAL CONVECTION ON SAT WILL WANE DURING THE EVE WITH THE LOSS OF DAYTIME HEATING. SAT NGT WILL BE MUGGY...WITH MIN TEMPS RANGING FROM THE MID 60S IN THE HIGHLANDS TO MID 70S ALONG AND EAST OF I-95. SHORTWAVE TROUGH OVER THE UPPER MIDWEST ERY SUN IS FCST TO LIFT NEWD ACROSS THE GREAT LAKES DURING THE DAY. THIS SHORTWAVE ENERGY WILL BE WEAKENING DURING THIS TIME AS THE UPPER-JET STREAK AHEAD OF THE TROUGH LIFTS NEWD INTO ERN CANADA. THE MID- ATLANTIC REGION WILL BE SITUATED IN THE PRE- FRONTAL WARM- MOIST SECTOR ON SUN AS A SFC COLD FRONT MOVES INTO THE OH VLY. AFTN TEMPS IN THE LOWER 90S AND DEWPOINTS IN LOWER 70S ON SUN WILL YIELD A MODERATE AMT OF INSTABILITY...AROUND 1.5-2 KJ/KG...BY THE AFTN. COVERAGE AND ORGANIZATION OF CONVECTION SHOULD BE BETTER NORTH AND WEST OF THE REGION...WHERE THE BEST SYNOPTIC LIFT ASSOCIATED WITH THE TROUGH/COLD FRONT RESIDE. GIVEN THE STEEP LLVL LAPSE RATES AND APPROACH OF A 30-KT LLVL JET BY EVE...A FEW STORMS MAY BECOME SEVERE DURING THE PEAK HEATING HRS. COLD FRONT WILL MOVE THRU SUN NGT. IF FRONT MOVES THRU EARLIER THAN 12Z MODELS INDICATE...THEN ORGANIZED CONVECTION AND A DAMAGING WIND THREAT MAY EXTEND EWD TOWARD THE WRN TERRAIN AND NRN MD DURING THE EVE. HOWEVER...ATMOSPHERE WILL BE LESS CONDUCIVE FOR SEVERE WEATHER FARTHER SOUTH AND EAST WHEN FRONT MOVES THRU SEVERAL HRS AFTER SUNSET. && .LONG TERM /MONDAY THROUGH FRIDAY/... AN UPPER-LEVEL TROUGH MOVES OVER THE REGION NEXT WEEK WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPS EXPECTED FOR EARLY AUGUST. THE SURFACE COLD FRONT THAT IS EXPECTED TO MOVE THROUGH THE REGION MONDAY SHOULD STALL TO THE SOUTH AS A BERMUDA HIGH PERSISTS IN THE ATLANTIC. LIFT ASSOCIATED WITH THE FRONT MAY PRODUCE SHOWERS AND THUNDERSTORMS BUT ACTIVITY SHOULD TO THE SOUTH THROUGH THE PERIOD. GFS AND ECMWF BRING FRONT NORTHWARD ON WEDNESDAY WHICH MAY PRODUCE SHOWERS AND THUNDERSTORMS ESPECIALLY FOR THE SOUTHERN HALF OF THE CWA. TROUGH WILL EVENUTALLY FLATTEN AND MOVE EASTWARD TOWARD THE END OF NEXT WEEK BEFORE THE NEXT WAVE ARRIVES NEXT FRIDAY. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... EXCEPT FOR A STRAY SHOWER...AREA SHOULD BE DRY OVERNIGHT. LIKE LAST NIGHT...SOME FOG MAY FORM AT MRB/CHO/IAD. MRB WENT DOWN TO IFR LAST NIGHT...AND LEANED TOWARD PERSISTENCE. CHO RECEIVED RAIN THIS EVENING...SO IFR MAY BE MORE LIKELY LATE TONIGHT. KEPT IAD IN MVFR TOWARD SUNRISE. VFR WILL PREVAIL FOR SATURDAY...BUT WILL HAVE TO WATCH SCATTERED THUNDERSTORMS POPPING UP IN THE AFTERNOON. A COLD FRONT WILL APPROACH FROM THE NW SUN. SCT STORMS AHEAD OF THE FRONT SUN AFTN WILL INCREASE IN COVERAGE LATE IN THE DAY AND AT NGT AS THE COLD FRONT MOVES THRU. TEMPORARY RESTRICTIONS EXPECTED IN STORMS. VSBY RESTRICTIONS POSSIBLE IN FOG LATE SUN NGT...ESPECIALLY AT TERMINALS THAT WERE IMPACTED BY EARLIER STORMS. AS FRONT LINGERS TO THE SOUTH...VFR CONDITION EXPECTED MOST OF THE TIME. SHOWERS AND THUNDERSTORMS MAY CAUSE BRIEF PERIODS OF REDUCED VISBYS MAINLY FOR CHO TOWARDS THE END OF NEXT WEEK. LIGHT S-SW FLOW EXPECTED THROUGH THE PERIOD. && .MARINE... RISK OF THUNDERSTORMS HAS DIMINISHED OVER THE WATERS OVERNIGHT. SOUTHERLY FLOW WILL CHANNEL UP THE BAY...PRODUCING UP TO 15 KT AT TIMES WITHIN THE MAIN CHANNEL. SCATTERED THUNDERSTORMS MAY PRODUCE GUSTY WINDS SATURDAY AFTERNOON. SCA HAS BEEN ISSUED FOR SAT NGT FOR THE MOUTH OF THE TIDAL POTOMAC RVR AND SRN ZONES OF THE MD CHSPK BAY...WHERE SLY CHANNELING WILL PRODUCE 20-KT GUSTS. SCA CONDITIONS POSSIBLE FOR MOST MARINE ZONES AS SLY WINDS INCREASE AHEAD OF A COLD FRONT. A FEW STORMS AHEAD OF THE FRONT COULD PRODUCE GUSTY WINDS LATE SUN. AS FRONT LINGERS SOUTH OF THE WATERS NEXT WEEK...LIGHT SOUTHWESTERLY FLOW EXPECTED. && .TIDES/COASTAL FLOODING... WILL HAVE TO WATCH SENSITIVE AREAS SUCH AS ALEXANDRIA AND ANNAPOLIS AGAIN DURING HIGH TIDE SATURDAY MORNING. IT WOULD TAKE AN ANOMALY OF AROUND 0.8 TO HIT MINOR TIDAL FLOODING THRESHOLDS AT ANNAPOLIS. ANOMALY IS AROUND 0.6. THIS HAS BEEN FAIRLY STEADY THUS FAR. WITH SOUTHERLY WINDS...THERE IS THE CHANCE THIS COULD CREEP UP A LITTLE MORE...BUT DON/T HAVE THE CONFIDENCE IN HITTING CRITERIA ATTM. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM SATURDAY TO 6 AM EDT SUNDAY FOR ANZ533-534-537-541-543. && $$ BPP/WOODY!/KLEIN |
| #531621 (Received by flhurricane at: 9:23 PM 03.Aug.2012) AFDMLB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 845 PM EDT FRI AUG 3 2012 .DISCUSSION... ...TROPICAL MOISTURE TO MOVE OVER THE AREA THIS WEEKEND... ...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE... CURRENTLY-SAT...THE LATEST TROPICAL SURFACE ANALYSIS FROM NHC SHOWS AN INVERTED TROUGH OVER THE NORTHWEST BAHAMAS. THIS FEATURE HAS BEEN MOVING VERY SLOWLY THE PAST 24 HOURS AND THIS TREND IS FORECAST TO CONTINUE. CONVECTION ALONG/EAST OF THE TROUGH IS BEING ENHANCED BY AN UPPER LEVEL TROUGH DRIFTING WESTWARD INTO THE EASTERN GULF. AXIS OF ATLANTIC SURFACE RIDGE HAS SHIFTED NORTH OF THE AREA WHICH IS CAUSING AN ONSHORE WIND FLOW. EXPECT ISOLATED SHOWERS TO PUSH ONSHORE TONIGHT...THEN AS AXIS OF SURFACE TROUGH CREEPS INTO THE PENINSULA EARLY SAT...SHOWERS/STORMS WILL INCREASE DURING THE MORNING AND AFTERNOON. THOUGH THIS SYSTEM IS STILL POORLY ORGANIZED...AS THE UPPER TROUGH PUSHES FARTHER WEST INTO THE GULF...THE WINDS ALOFT WILL DECREASE. THAT IS WHY NHC MAINTAINS A SLIGHT CHANCE FOR TROPICAL DEVELOPMENT. REGARDLESS OF HOW THIS SYSTEM EVOLVES...THERE WILL BE A CHANCE FOR INCREASED COVERAGE OF HEAVY RAIN AMOUNTS SAT AND CONTINUING SUNDAY. THE ONLY CHANGE TO THE GRIDS/FORECAST WILL BE TO REMOVE POPS ACROSS THE INTERIOR TONIGHT. && .AVIATION...THERE WILL BE A SLIGHT CHANCE FOR SHOWERS WITH MVFR CONDITIONS ALONG THE COAST TONIGHT. EXPECT THAT AS AXIS OF SURFACE TROUGH APPROACHES LATE TONIGHT...COVERAGE WILL INCREASE MAINLY KMLB-KSUA. THIS LATE NIGHT ACTIVITY SHOULD CONTINUE PAST SUNRISE THEN BY AFTERNOON THE FOCUS WILL SHIFT TO THE INTERIOR TERMINALS... WHERE STRONGER STORMS WILL BE POSSIBLE AGAIN. && .MARINE... TONIGHT-SAT...A LOW PRESSURE WAVE OVER THE NORTHERN BAHAMAS IS FORECAST TO PUSH SLOWLY INTO AND ACROSS SOUTH FLORIDA ON SAT. THIS WILL CAUSE EAST/SOUTHEAST WINDS TO INCREASE. RIGHT NOW THE MODELS ARE INDICATING 15 TO 20 KNOTS. THINGS COULD CHANGE THOUGH... DEPENDING ON WHETHER ANY ORGANIZATION OCCURS WITH THIS TROUGH OF LOW PRESSURE. REGARDLESS OF HOW THE WINDS/SEAS EVOLVE...THE COVERAGE OF SHOWERS AND STORMS WILL INCREASE SUBSTANTIALLY. SO CONDITIONS FOR BOATERS WILL BE POOR WITH PERIODIC DOWNPOURS AND HIGHER WINDS/SEAS WITH THE CONVECTIVE ACTIVITY. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ |
| #531620 (Received by flhurricane at: 8:42 PM 03.Aug.2012) AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 638 PM CDT FRI AUG 3 2012 .AVIATION... VFR CONDITIONS WILL PERSIST TONIGHT. HOWEVER...SLIGHT CHANGES ARE IN STORE BEGINNING ON SATURDAY. DEEPER LAYER MOISTURE OVER THE NORTH CENTRAL GULF WILL ADVECT WESTWARD AND BRING SLIGHT CHANCES FOR SHOWERS TO THE COAST DURING THE EARLY MORNING PERIOD AROUND AND AFTER SUNRISE TO KGLS. CANNOT RULE OUT A SHOWER FOR KHOU GIVEN THE MODEL SOLUTIONS...BUT FELT THAT THE CHANCES WERE TOO SMALL TO MENTION. AN INCREASE IN MOISTURE WILL ALSO BRING BETTER CHANCES FOR MVFR CEILINGS OVER SOME LOCATIONS INLAND OF THE BIG HOUSTON AIRPORTS BETWEEN 11Z AND 15Z. 40 && .PREV DISCUSSION... /ISSUED 350 PM CDT FRI AUG 3 2012/ DISCUSSION... DRY AND WARM WEATHER CONTINUES AS THE UPPER LEVEL RIDGE REMAINS CENTERED ACROSS THE STATE. MODELS IN GOOD AGREEMENT IN SHIFTING THE RIDGE BACK TO THE WEST OVER THE WEEKEND AND ALLOWING INCREASED MOISTURE TO FLOW INTO THE REGION. RAIN CHANCES WILL BE ON THE INCREASE THROUGH THE BEGINNING OF NEXT WEEK AS LOWER HEIGHTS AND PW VALUES OF AROUND 2.O INCHES WILL ALLOW FOR GREATER DEVELOPMENT ALONG THE SEABREEZE DURING THE AFTERNOON HOURS. MONDAY STILL LOOKS TO HOLD THE GREATEST CHANCE FOR RAIN AND WILL KEEP CURRENT CHANCE POPS IN PLACE. THE RIDGE LOOKS TO REMAIN WELL TO THE WEST THROUGH MUCH OF THE WEEK...ALTHOUGH IT WILL BEGIN TO REDEVELOP SLIGHTLY FURTHER NORTH BEFORE DRIFTING BACK TO THE EAST. THIS SHOULD ALLOW FOR TYPICAL SUMMERTIME CONDITIONS WITH AFTERNOON SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE COASTAL COUNTIES AND THEN MOVING INLAND WITH THE SEABREEZE. TEMPERATURES WILL BE SLIGHTLY COOLER THAN THIS WEEK BUT STILL EXPECTING MOST AREAS TO REACH THE LOW TO MID 90S EACH AFTERNOON NEXT WEEK. WE CONTINUE TO KEEP AN EYE ON TS ERNESTO WHICH IS LOOKING SOMEWHAT DISORGANIZED AS IT CONTINUES ON ITS CURRENT WEST NORTHWESTWARD TRACK. THE OFFICIAL NHC FORECAST TRACK TAKES IT ASHORE ALONG THE YUCATAN PENINSULA AROUND THE MIDDLE OF NEXT WEEK. 38 MARINE... ANOTHER DAY AND HALF OF WINDS 10-15 KNOTS BEFORE UPPER RIDGING RETREATS AND WINDS BECOME MORE SOUTH TO SOUTHEAST AND DRIVEN BY LAX GRADIENT/DIURNAL HEATING. SEAS SHOULD LOWER UNTIL WINDS BEGIN TO INCREASE AGAIN TOWARD THE MIDDLE OF THE WEEK. STILL TO FAR OUT FOR MUCH CONFIDENCE ON ERNESTO HAVING MUCH IF ANY IMPACT TO THE MARINE WATERS. A LITTLE MORE CONCERNED ABOUT THE SYSTEM EAST OF FLORIDA MOVING TOWARD NEW AND BRINGING ABUNDANT MOISTURE TO THE UPPER TEXAS COASTAL WATERS AND INCREASED COVERAGE OF SHOWERS AND THUNDERSTORMS. 45 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 76 98 76 98 76 / 0 10 10 20 10 HOUSTON (IAH) 78 94 78 94 75 / 0 20 10 30 10 GALVESTON (GLS) 82 91 82 91 80 / 0 20 20 30 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531619 (Received by flhurricane at: 8:41 PM 03.Aug.2012) AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 723 PM EDT FRI AUG 3 2012 .AVIATION... LATEST SHORT TERM GUIDANCE KEEPS CONVECTION OFFSHORE THE ATLANTIC WATERS THROUGH THE NIGHT. AS A RESULT...SCT CLOUDS AND LIGHT EASTERLY WINDS SHOULD PREVAIL. SHRAS/TSRAS WILL BEGIN TO PUSH BACK INTO THE SOUTH FLORIDA PENINSULA BY LATE MORNING TOMORROW AS A TROUGH MOVES CLOSER TO THE AREA. THIS COMBINED WITH DIURNAL SEA BREEZE INTERACTIONS WILL ALLOW CONVECTION TO BE FAIRLY WIDESPREAD ACROSS SOUTH FLORIDA THROUGH MUCH OF THE DAY TOMORROW. && .PREV DISCUSSION... /ISSUED 259 PM EDT FRI AUG 3 2012/ SHORT TERM...(TONIGHT-MONDAY) THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING NORTH- NORTHEAST JUST EAST OF SOUTH FLORIDA TO THE NW BAHAMAS WITH MOST OF THE SHOWER/TSTM COVERAGE REMAINING AROUND THE TROUGH AXIS...INCLUDING OUR ADJACENT ATLANTIC WATERS. THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS SURFACE TROUGH JUST EAST OF THE LOCAL AREA AND GENERALLY INDICATES IT CONTINUING WESTWARD OVER SOUTH FLORIDA THROUGH THE DAY SATURDAY...POSSIBLY AS A WEAK LOW. AS A RESULT...WE WILL ADJUST THE RAINFALL CHANCES UP THROUGH THIS PERIOD OVER THE WEEKEND FROM WHAT WAS ADVERTISED IN THE PREVIOUS PACKAGE. THE NAM SOLUTION REMAINS THE OUTLIER AND INDICATES THIS FEATURE DEVELOPING A WELL DEFINED LOW-LEVEL CIRCULATION CENTER AND ADVANCING NW AND MOVING ASHORE ALONG THE EAST-CENTRAL PORTION OF THE FLORIDA PENINSULA LATER SATURDAY NIGHT. FOR THIS PACKAGE...WE WILL REMAIN CLOSER TO THE LATEST GFS/ECMWF SOLUTIONS AND GENERALLY SHOW IT CONTINUING WEST ACROSS THE AREA OVER THE WEEKEND. SUNDAY THROUGH MONDAY...MOIST SOUTHEAST FLOW WILL BE EXPECTED AS THE AFOREMENTIONED SURFACE TROUGH/UPPER LOW CONTINUES WEST AND AWAY FROM THE FL PENINSULA AND ERNESTO CONTINUES ITS WESTWARD TRACK ACROSS THE CARIBBEAN. MODERATE EASTERLY FLOW DUE TO AN ENHANCED GRADIENT BETWEEN ERNESTO TO THE SOUTH AND THE SUBTROPICAL RIDGE TO THE NORTH COMBINED WITH PRECIPITABLE WATER VALUES AROUND THE TWO INCH MARK WILL KEEP THE RAIN CHANCES IN THE FORECAST THROUGH THE PERIOD. LONG TERM...(MONDAY NIGHT-THURSDAY)... THE CHANCE OF RAIN TAPERS OFF FROM MIDWEEK ON AS THE ATLC HIGH CENTER MOVES WESTWARD PULLING SOME DRIER AIR OVER S FLA. A DEEP EASTERLY WIND FLOW DICTATES THAT THE HIGHER POPS WILL BE IN THE W INTERIOR AND W COAST. FORECASTED HURRICANE ERNESTO APPROACHES THE YUCATAN PENINSULA BY MID WEEK. AS ERNESTO TRACKS WESTWARD...AT THIS TIME...THE ONLY EFFECT TO S FLA WILL BE AN INCREASE IN THE LOW LEVEL EASTERLY WINDS FROM MIDWEEK ON. BUT KEEP AWARE OF NHC FORECASTS OF THE DEVELOPMENT AND FORECASTED MOVEMENT OF THIS STORM. MARINE... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE EXPECTED ACROSS THE ATLANTIC WATERS TONIGHT THROUGH SATURDAY AS A TROUGH OF LOW PRESSURE TRACKS WEST OVER THE AREA. WINDS AND SEAS WILL BE LOCALLY HIGHER IN AND AROUND THE HEAVIER SHOWERS AND STORMS THROUGH THIS TIME. EASTERLY WINDS ARE EXPECTED TO REACH THE MODERATE LEVELS INTO THE UPCOMING WEEK AS THIS TROUGH SHIFTS WEST OF THE MARINE AREAS AND TROPICAL STORM ERNESTO PASSES WELL SOUTH. FIRE WEATHER... NO CONCERNS THROUGH THE WEEKEND AND INTO THE UPCOMING WEEK AS PLENTY OF MOISTURE AND RAIN CHANCES REMAIN IN THE FORECAST. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 89 77 88 / 30 70 50 40 FORT LAUDERDALE 79 90 79 89 / 30 70 50 40 MIAMI 78 89 78 90 / 30 70 50 40 NAPLES 76 91 76 92 / 20 50 50 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ |
| #531618 (Received by flhurricane at: 8:35 PM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 823 PM EDT FRI AUG 3 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL STALL OVER THE REGION TONIGHT... BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HOT AND HUMID CONDITIONS WILL CONTINUE TOMORROW AND SUNDAY. A STRONGER COLD FRONT WILL CROSS THE REGION LATE SUNDAY NIGHT OR MONDAY BRINGING ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE AREA. HIGH PRESSURE BUILDS OVER THE REGION MONDAY THROUGH WEDNESDAY WITH DRIER CONDITIONS EXPECTED. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... UPDATE...WILL TWEAK POPS AGAIN AS THE LAST OF THE CONVECTION MOVES OFF THE MID COAST OF MAINE. LOADED CURRENT OBS TO KEEP TEMPS AND DEWPOINTS FRESH. WILL ISSUE DIGITAL PRODUCTS. PREV DISC...WEAK FRONTAL BOUNDARY APPROACHING THE AREA THIS AFTERNOON FROM THE NORTHWEST. VISIBLE SATELLITE IMAGERY SHOWS DECENT CLEARING ACROSS MOST OF THE FORECAST AREA. MODIFIED 12Z KGYX SOUNDING INDICATES UPWARDS OF 2500J/KG WORTH OF CAPE TO WORK WITH. ALTHOUGH SHEAR IS WEAK...EXPECT SOME SCATTERED STORMS TO DEVELOP THIS AFTERNOON AND EVENING. SOME MAY BE STRONG ENOUGH TO REACH SEVERE LIMITS...BUT THEY SHOULD BE PRETTY ISOLATED. ONCE DIURNAL HEATING FADES CONVECTION SHOULD DIE OFF PRETTY QUICKLY. WITH DEWPOINTS STILL WELL INTO THE 60S...EXPECT FOG TO SET UP AGAIN ACROSS MUCH OF THE AREA. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... FOG AND STRATUS SHOULD BURN OFF DURING THE MORNING HOURS TOMORROW. FRONTAL BOUNDARY STALLED TO OUR SOUTH WILL START TO MAKE ITS WAY NORTHWARD AS A WEAK WARM FRONT. NOT MUCH LEFT IN THE WAY OF DYNAMICS WITH THE BOUNDARY AND SHOWERS AND THUNDERSTORMS MAY BE LIMITED TO WESTERN PORTIONS OF CWA AND THE MOUNTAINS. EXPECT CLEARING GOING INTO SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... SOUTHERLY FLOW TRANSPORTS MORE MOISTURE INTO THE REGION ON SUNDAY IN ADVANCE OF AN APPROACHING TROUGH. WILL PROBABLY SEE FOG ALONG THE COAST WHICH MAY LAST INTO THE AFTERNOON ESPECIALLY ON THE MIDCOAST. OUTSIDE OF FOGGY AREAS... TEMPERATURES WILL WARM WELL INTO THE 80S. TIMING OF THE TROUGH AND ASSOCIATED COLD FRONT SEEM TO SUGGEST THAT PRECIPITATION WILL BE LATER IN ARRIVING. SHOULD SEE A CHANCE OF SHOWERS AND THUNDERSTORMS LATE SUNDAY AFTERNOON AND THROUGH SUNDAY NIGHT. THIS TIMING MEANS THE SEVERE WEATHER THREAT WILL BE MINIMIZED. HOWEVER... EVEN WITH THE PASSAGE DURING THE NIGHTTIME HOURS IN THE ABSENCE OF SURFACE BASED INSTABILITY... INSTABILITY ALOFT GENERATED BY THE TROUGH AND COLD ADVECTION ALOFT MAY BE ENOUGH TO KEEP THUNDERSTORMS GOING. SHEAR WOULD BE SUFFICIENT FOR SUPERCELLS AND BOWING MULTICELL STORMS GIVEN ENOUGH INSTABILITY. COLD FRONT MAKES A FULL PASSAGE THROUGH THE AREA BY MONDAY MORNING OR EARLY MONDAY AFTERNOON. MAY STILL SEE SOME SHOWERS AND STORMS LINGERING AHEAD OF THE FRONT THROUGH EARLY MONDAY. OTHERWISE WILL SEE A CLEARING AND DRYING TREND AS HIGH PRESSURE BUILDS IN FROM THE WEST. HIGH PRESSURE GENERALLY HOLDS THROUGH TUESDAY... ALTHOUGH A WEAK SHORTWAVE TROUGH CROSSES JUST NORTH OF THE INTERNATIONAL BORDER. ANOTHER SHORTWAVE TROUGH DIGS FURTHER SOUTH ON WEDNESDAY AND THURSDAY... WITH SHOWERS AND THUNDERSTORMS POSSIBLE PRIMARILY DURING THE AFTERNOON EACH DAY OVER INTERIOR LOCATIONS. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM...EXPECT VFR CONDITIONS TO DETERIORATE TONIGHT TO IFR/LIFR CONDITIONS IN FOG. FOG WILL LIFT BY MID-MORNING TOMORROW WITH VFR CONDITIONS RETURNING AND REMAINING IN PLACE FOR THE REMAINDER OF THE SHORT TERM PERIOD. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...WILL PROBABLY SEE FOG RETURN SATURDAY NIGHT INTO EARLY SUNDAY ALONG THE COAST. FOG WILL LINGER LONGEST ALONG THE MIDCOAST NEAR ROCKLAND AND MAY EVEN LAST THROUGH THE AFTERNOON. EXPECT SHOWERS AND THUNDERSTORMS LATE SUNDAY THROUGH EARLY MONDAY. GENERALLY VFR AFTER THE COLD FRONT MOVES THROUGH ON MONDAY THROUGH THE MIDDLE OF THE WEEK. && .MARINE... SHORT TERM /THROUGH SATURDAY...A WEAK FRONT DROPS INTO THE GULF OF MAINE ON FRIDAY BEFORE DISSIPATING. WINDS AND SEAS SHOULD REMAIN FAIRLY QUIET. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...SOUTHERLY FLOW WILL INCREASE IN ADVANCE OF AN APPROACHING COLD FRONT ON SUNDAY. ALTHOUGH WINDS MAY STAY BELOW 25 KT... SEAS WILL GRADUALLY BUILD ON THE SOUTHERLY FETCH AND WAVE HEIGHTS MAY EXCEED 5 FEET. THE COLD FRONT WILL CROSS THE WATERS ON MONDAY WITH A RETURN TO MORE TRANQUIL CONDITIONS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ SYNOPSIS... |
| #531617 (Received by flhurricane at: 8:24 PM 03.Aug.2012) AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 620 PM CDT FRI AUG 3 2012 .AVIATION...MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD, HOWEVER THERE WILL BE ISOLATED TSRA AROUND THE REGION BY MID DAY SATURDAY. CB IS DISPLAYED IN TAF, HOWEVER NO VCTS DUE TO LOW COVERAGE, BUT MAY BE ADDED LATER. WINDS WILL BE LIGHT AND GENERALLY SOUTH TO SOUTHWEST. && .PREV DISCUSSION... /ISSUED 440 PM CDT FRI AUG 3 2012/ DISCUSSION... LATEST WATER VAPOR SATELLITE IMAGERY/UPPER AIR ANALYSIS SHOWED UPPER RIDGE CENTERED OVER CENTRAL/EASTERN TEXAS...WITH A DISCERNIBLE SHORTWAVE EVIDENT DROPPING SOUTH THROUGH CENTRAL LOUISIANA. AT THE SFC...HIGH PRESSURE RIDGES WWD FROM THE ATLANTIC ACROSS THE NORTHERN GULF OF MEXICO. LATEST RADAR IMAGERY SHOWERS ISOLATED-SCATTERED CONVECTION ONGOING ACROSS SOUTH CENTRAL/SOUTHEAST LA. HAVE KEPT THE EVENING AND OVERNIGHT FCST DRY WITH THE IDEA THAT THE LOSS OF DAYTIME HEATING SHOULD RESULT IN THIS ACTIVITY WANING...BUT WITH THE LIFT ASSOCIATED WITH THE PASSING SHORTWAVE...IT MAY CONTINUE INTO THE EVENING HOURS...AND WOULD NOT BE SURPRISED IF THE EVENING CREW HAD TO EXTEND A SMALL POP BEYOND 00Z. NO MAJOR CHANGES WERE MADE TO THE GRIDDED FORECAST THIS AFTERNOON. GLOBAL MODELS CONTINUE TO SHOW THE MID/UPPER RIDGE LIFT A BIT TO THE NORTH TOMORROW...BEFORE RETROGRADING WWD ON SUNDAY...WITH DEEPER MOISTURE WORKING ITS WAY WEST INTO THE REGION. THIS...ALONG WITH SHORTWAVE ENERGY SLIDING UNDERNEATH THE RIDGE TOMORROW...AND TRAVERSING THE REGION ON SUNDAY...WILL RESULT IN INCREASING RAIN CHANCES THROUGH THE WEEKEND. THE RIDGE IS FCST TO CONTINUE WWD AND AMPLIFY OVER THE FOUR CORNERS REGION NEXT WEEK...LEAVING THE REGION WITHIN A WEAKNESS/SHEAR AXIS BETWEEN THIS RIDGE AND THE SUBTROPICAL RIDGE TO THE EAST. OTHER THAN MONDAY AND PERHAPS INTO TUESDAY...WHEN AN INVERTED UPPER TROF IS PROGGED TO PASS TO OUR SOUTH...DID NOT SEE ANYTHING CONCRETE TO HANG MY HAT ON IN TERMS OF RAISING RAIN CHANCES ABOVE CLIMO...BUT BEING IN NW FLOW ALOFT CAN OFTEN BRING SURPRISES. REGARDING THE TROPICS...THE PROGRESS OF ERNESTO WILL OF COURSE CONTINUE TO BE MONITORED. THE LATEST OFFICIAL TRACK FROM NHC BRINGS ERNESTO TO THE YUCATAN PENINSULA AS A HURRICANE BY WEDNESDAY AFTERNOON...WITH A COORDINATED NHC/HPC TRACK CONTINUING A GENERAL NW MOTION INTO THE SW GULF ON DAYS 6 AND 7. THERE REMAINS A LARGE MODEL SPREAD IN THIS LATTER PART OF THE FORECAST...THUS RESIDENTS ARE ENCOURAGED TO KEEP UP WITH THE LATEST NHC FORECASTS. 13 MARINE... SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE ACROSS THE NORTHERN GULF OF MEXICO FROM THE WESTERN ATLANTIC. THIS WILL RESULT IN MAINLY ONSHORE FLOW AND RELATIVELY LOW SEAS THROUGH THE WEEKEND...HEADING INTO NEXT WEEK. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 80 92 77 92 76 / 10 20 10 60 20 KBPT 76 92 77 92 76 / 10 20 10 60 20 KAEX 77 96 76 94 75 / 10 20 10 50 20 KLFT 77 92 76 91 75 / 10 20 20 60 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ |
| #531616 (Received by flhurricane at: 8:18 PM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 737 PM EDT FRI AUG 3 2012 .SYNOPSIS... LARGE HIGH PRESSURE OFF THE ATLANTIC COAST WILL REMAIN STATIONARY THROUGH SATURDAY. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY... THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... WARM AND MUGGY CONDITIONS CONTINUE OVERNIGHT WITH DEW POINTS IN THE UPPER 60S TO LOWER 70S ACROSS THE AREA AND EXPECTED TO STAY THERE THROUGH THE NIGHT. STILL A FAIR AMOUNT OF INSTABILITY ACROSS THE AREA MOSTLY DUE TO THIS AIR MASS. HOWEVER...NO TRIGGER IS IN PLACE WITH THE COLD FRONT WELL TO THE WEST. HAVE BEEN WATCHING THE THUNDERSTORMS IN CENTRAL NJ BUT THEY ARE NOW DISSIPATING AND ARE NOT EXPECTED TO MAKE IT THIS FAR NORTH. STILL A SLIGHT CHANCE IN AREAS NORTH AND WEST THAT A SHOWER DOES DEVELOP IN THE NEXT FEW HOURS WITH THE LEFTOVER INSTABILITY BUT NOTHING SEVERE EXPECTED. OTHERWISE...TEMPS WILL DROP SLOWLY TONIGHT...WITH MANY LOCATIONS REMAINING IN THE 70S PER MOS. MID TO UPPER 60S ACROSS THE INTERIOR. DO EXPECT PATCHY FOG AS LIGHT SOUTHERLY WINDS PERSIST AND TEMP/DEW POINT DEPRESSIONS SHRINK. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... LARGE RIDGE OVER THE WESTERN ATLANTIC AND UP THE EASTERN SEABOARD PREVAILS THIS TIME FRAME. WITH THIS RIDGE IN PLACE...LIGHT WINDS AND PLENTY OF WARM AIR ALOFT SHOULD KEEP ANY AFTERNOON/EVENING CONVECTION TO A MINIMUM. SLIGHTLY COOLER BOUNDARY LAYER WILL RESULT IN LOWER SFC/MIXED LAYER INSTABILITY AS WELL. HOWEVER...ANY SHOWER OR THUNDERSTORM THAT DOES DEVELOP WILL PULSE BRIEFLY...AND COULD BE STRONG. THE COOLER BOUNDARY LAYER IS COURTESY OF INCREASING SOUTH TO SOUTHEAST FLOW...INJECTING MARINE LAYER OVER A GOOD PORTION OF THE CWA. HOWEVER TEMPS WILL STILL BE QUITE WARM TO HOT...80S TO NEAR 90. WITH HIGH DEW POINTS REMAINING IN THE 70S...HEAT INDICES WILL ONCE AGAIN RISE INTO THE 90S. A FEW LOCATIONS IN AND AROUND NYC COULD SEE 95 DEGREE HEAT INDICES...BUT GIVEN UNCERTAINTY AND MARGINAL CONDITIONS...WILL HOLD OFF ON ANY HEAT ADVISORIES AT THIS TIME. TIME OF YEAR A FACTOR WITH SEVERAL HEAT EVENTS UNDER OUR BELT AS WELL. THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN FACING BEACHES ON SATURDAY. ON SATURDAY NIGHT...MUGGY AND WARM CONDITIONS CONTINUE WITH SOUTH FLOW PERSISTING. STRATUS AND FOG EXPECTED ONCE AGAIN. FOLLOWED A MOS BLEND CLOSELY THROUGH THIS TIME PERIOD. HARD TO BEAT MOS NUMBERS IN THIS TYPE OF STAGNANT/PERSISTENT PATTERN. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HOT AND HUMID AIRMASS IN PLACE SUNDAY AS STRONG SOUTHERLY WINDS DEVELOP DUE TO A TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRES ANCHORED OVER THE WESTERN ATLANTIC AND AN APPROACHING COLD FRONT MOVING THROUGH THE OHIO VALLEY. CONDITIONS BECOME QUITE UNSTABLE AS TEMPS CLIMB THROUGH THE 80S...AROUND 90 IN/AROUND NYC...ALONG WITH SFC DEW POINTS WELL INTO THE 70S. THIS WILL RESULT IN A HEAT INDEX CLOSE TO 100 DEGREES IN/AROUND NYC AND THE URBANIZED AREAS OF NE NJ...AND IN THE LOW TO MID 90S ELSEWHERE. STRONG SOUTHERLY FLOW...COMBINED WITH INCREASING SURF HEIGHTS... WILL LIKELY RESULT IN A HIGH RISK FOR RIP CURRENTS AT THE OCEAN BEACHES ON SUNDAY. THERE MAY BE A FEW SHOWERS/TSTMS LINGERING INTO SUNDAY MORNING AS WEAK TROUGH/SHORTWAVE MOVE THROUGH THE REGION...BUT MORE ORGANIZED ACTIVITY WILL HOLD OFF UNTIL THE AFTERNOON AND EVENING HOURS AS THE COLD FRONT OVER THE OH VALLEY MOVES INTO WESTERN NY/PA DURING THE DAY SUNDAY. PRE-FRONTAL TROUGH AHEAD OF THE COLD FRONT WILL TRACK INTO WESTERN PORTIONS OF THE FORECAST AREA BY AFTERNOON...AND THAT LOOKS TO BE A TRIGGERING MECHANISM FOR SOME RATHER STRONG TO SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING. CAPE VALUES WILL BE OVER 2000 J/KG IN SOME PARTS OF NJ AND INTO NYC...ALONG WITH A LIFTED INDEX CLOSE TO -7 C AND INCREASING LOW LEVEL WINDS. AS THIS COMPLEX COLD FRONT/UPPER TROUGH/SHORTWAVE SYSTEM MOVES INTO THE AREA SUNDAY EVENING...SHOWERS AND THUNDERSTORMS WILL INCREASE IN INTENSITY AND COVERAGE SUNDAY EVENING. THUNDERSTORMS WILL BE CAPABLE OF DAMAGING WINDS IN THE AFTERNOON...BUT WITH LOSS OF DIURNAL HEATING COMES THE LOSS OF THE THREAT FOR DAMAGING WINDS. IN ADDITION TO THE DAMAGING WIND THREAT...THERE IS ALSO THE THREAT FOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING IN THE AFTERNOON/EVENING...THEN TORRENTIAL RAINFALL SUNDAY NIGHT WILL RESULT IN THE POTENTIAL FOR FLASH FLOODING OVERNIGHT SUNDAY NIGHT INTO MONDAY MORNING. WITH PWATS RANGING FROM 2.25-2.5 INCHES...THERE IS ABUNDANT MOISTURE IN THE ATMOSPHERE TO FEED ANY THUNDERSTORMS. THINK THE MID LEVEL WINDS WILL BE TOO STRONG TO ALLOW ANY STORM TO LINGER OVER ANY ONE AREA...BUT TRAINING OF CELLS WILL LEAD TO FLASH FLOODING. PRECIPITATION TAPERS OFF FROM WEST TO EAST MONDAY MORNING AS THE FRONTAL SYSTEM TRACKS THROUGH THE REGION. THE FRONT BECOMES STATIONARY SOUTH OF LONG ISLAND LATE MONDAY THROUGH TUESDAY AS HIGH PRES BUILDS THROUGH THE REGION ON TUESDAY. HUMIDITY LEVELS WILL FALL DRASTICALLY AS DEW POINTS DROP FROM THE 70S INTO THE LOWER 60S. TUESDAY WILL END UP QUITE PLEASANT WITH LOW HUMIDITY...FAIR SKIES AND TEMPS IN THE 80S. STATIONARY FRONT SOUTH OF LONG ISLAND LIFTS BACK NORTH AS A WARM FRONT ON WEDNESDAY. ISOLATED SHOWERS/TSTMS POSSIBLE WITH ITS PASSAGE. SFC COLD FRONT WITH UPPER LEVEL SUPPORT FROM AN H5 TROUGH/SHORTWAVE COMBO THEN APPROACHES ON THURSDAY...POSSIBLY TOUCHING OFF SOME MORE SHOWERS/TSTMS. SOME CONCERNS WITH FORECAST LATE IN THE WEEK...AS HIGH PRES MOVES THROUGH THE REGION...BUT DEPENDING ON HOW FAST IT DEPARTS WILL IMPACT IF LOW PRES UPSTREAM MAKES IT TO THE LOCAL AREA OR NOT. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /23Z FRIDAY THROUGH WEDNESDAY/... A WEAK PRESSURE PATTERN REMAINS IN PLACE THROUGH THE TAF PERIOD. VFR FOR THE FIRST HALF OF THE NIGHT WITH S-SSW WINDS DIMINISHING UNDER 10 KT. AFTER MIDNIGHT...FOG EXPECTED TO REDUCE THE VISIBILITY...BUT THIS IS A LOW CONFIDENCE FORECAST. IF FOG DOES DEVELOP...HIGHER CONFIDENCE THAT IT REMAINS HIGHER THAN IFR WITH THE EXCEPTION OF KGON AND KHPN. SEVERAL TERMINALS COULD END UP WITH GREATER THAN 5SM VISIBILITY ALL NIGHT. TIMING OF FOG ALSO DIFFICULT WITH SCT-BKN CIRRUS SHIFTING THROUGH...EVENTUALLY EXITING TO THE EAST. COULD BE A COUPLE HOURS TOO EARLY WITH THE TIMING OF FOG IN MOST CASES. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED THIS EVENING. KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED THIS EVENING. KEWR FCSTER COMMENTS: HAZE ALOFT OBSERVED. NO UNSCHEDULED AMENDMENTS ANTICIPATED THIS EVENING. KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED THIS EVENING. KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED THIS EVENING. KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED THIS EVENING. OUTLOOK FOR 00Z SUN THROUGH WED... .SAT NIGHT...ISOLD/SCT TSTMS POSSIBLE IN THE EVENING. IFR POSSIBLE AFTER MIDNIGHT. .SUN...EARLY IFR POSSIBLE. GUSTY S WINDS...MAINLY IN THE AFTERNOON. LATE DAY AND NIGHTTIME TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE/WED...VFR. && .MARINE... PERSISTENT SOUTHERLY FLOW CONTINUES TONIGHT THROUGH SATURDAY. SUB SCA CONDITIONS ARE ANTICIPATED. SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKE UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING ON SATURDAY. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH THE THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MPS/PW |
| #531614 (Received by flhurricane at: 7:57 PM 03.Aug.2012) AFDBRO AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BROWNSVILLE TX 623 PM CDT FRI AUG 3 2012 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH THE OVERNIGHT HOURS WITH CLEARING SKIES AND DIMINISHING WINDS. TOMORROW...THE OPPOSITE WILL OCCUR...WITH INCREASING WINDS AND SOME CLOUDINESS DEVELOPING. HOWEVER...VFR IS STILL FULLY ANTICIPATED. && .PREV DISCUSSION... /ISSUED 144 PM CDT FRI AUG 3 2012/ SHORT TERM.../THIS AFTERNOON THROUGH SATURDAY NIGHT/...STRONG MID AND UPPER RIDING PERSISTS OVER CENTRAL TEXAS...AND IS BASICALLY UNMOVED FROM 24 HOURS AGO. WEAKENING SURFACE RIDGING CENTERED A FEW HUNDRED MILES EAST OF THE LOWER TEXAS COAST IS CONTINUING TO PROVIDE A BREEZY DAY ACROSS THE REGION WITH THE THERMAL LOW SET UP EAST OF THE SIERRA MADRE MOUNTAINS. WITH THIS PATTERN WE REMAIN HOT AND BREEZY WITH FLOW FROM THE SOUTH SOUTHEAST. LOW LEVEL MOISTURE IS SLOWLY CREEPING IN...AND WE DO HAVE A LITTLE BETTER CUMULUS COVERAGE THAN WE DID THURSDAY...WITH SLIGHTLY MORE VERTICAL EXTENT...BUT THE SUBSIDENCE FROM UPPER RIDGING AND CONTINUAL MIXING OF DRIER AIR FROM THE MID AND LOWER LEVELS TO THE SURFACE IS KEEPING US DRY. A BUMP UP IN 700-850MB WINDS TONIGHT SHOULD KEEP BREEZES GOING A LITTLE LATER THAN NORMAL TODAY...LIKELY NOT SUBSIDING TOTALLY UNTIL AROUND 10 PM OR MIDNIGHT. A FEW VERY ISOLATED SHOWER MAY SPREAD INTO THE GULF WATERS...BUT EXPECT LAND AREAS TO STAY DRY. TOMORROW LITTLE CHANGE IS ANTICIPATED IN THE SYNOPTIC PATTERN...WITH THE UPPER RIDGE MOVING VERY SLIGHTLY WESTWARD IF AT ALL...AND THE SURFACE RIDGING TO THE EAST SLACKENING SLIGHTLY. OUR OVERALL MOISTURE NUDGES UPWARD A BIT...BUT FORECAST SOUNDINGS SHOW WE WOULD STILL NEED MECHANICAL LIFTING TO GET PARCELS GOING AND OUR GRADIENT SHOULD BE TOO STRONG TO GET A SOLID SEABREEZE BOUNDARY SET UP SO KEPT FORECAST HOT AND DRY. ANOTHER ROUND OF ISOLATED GULF SHOWERS IS POSSIBLE SATURDAY NIGHT. LONG TERM.../SUNDAY THROUGH FRIDAY/... UPPER LEVEL RIDGE OVER CENTRAL TEXAS FLATTENS AND MOVES WEST INTO THE FOUR CORNERS REGION SUNDAY INTO MONDAY. SURFACE HIGH OVER THE GULF WEAKENS PROVIDING A MORE LIGHTER SE FLOW ALONG THE WEST GULF COAST SUNDAY AFTERNOON. NAM12 SHOWS THE LATEST PWATS VALUES ABOVE 2 INCHES ALONG THE COASTAL COUNTIES SUNDAY. THIS WILL SET THE STAGE FOR SEABREEZE CONVECTION SUNDAY AFTERNOON. CHANCES OF RAIN WILL REPEAT MONDAY AS CONDITIONS ARE FAVORABLE FOR A FEW SHOWERS ONCE AGAIN. CHANCES DECREASE BY MID WEEK AS PWATS LOWER AROUND 1.5 IN AFTER WEDNESDAY WITH A STRENGTHENING CAP OVER THE RGV. THROUGH THE WEEK REALLY HOT TEMPERATURES CONTINUE FOR THE CWA REMAINING IN THE MID TO UPPER 100S WITH LOWS REACHING THE MID TO UPPER 70S. RIDGE WILL SHIFT FURTHER WEST KEEPING DRIER AIR INTO THE PACIFIC NORTHWEST. TROPICAL STORM ERNESTO SOUTH OF THE GREAT ANTILLES WILL MOVE WNW IN THE NEXT COUPLE OF DAYS. AT THIS TIME COOLER AND DRY AIR MAY INHIBIT ANY GROWTH IN THE NEXT COUPLE OF DAYS. MARINE...SMALL CRAFT EXERCISE CAUTION CONDITIONS WILL CONTINUE THIS AFTERNOON ON THE LAGUNA WITH SCEC CONDITIONS...AND POSSIBLY WIND CRITERIA FOR SMALL CRAFT ADVISORY BEING MET OVERNIGHT ON THE GULF WATERS. SEAS SHOULD NOT HAVE TIME TO RISE SIGNIFICANTLY WITH WAVE HEIGHTS UP TO AROUND 5 FEET BY SUNRISE IN PLACES. ANOTHER DAY OF SCEC CONDITIONS ON THE LAGUNA DURING THE DAY AND GULF WATERS DURING THE NIGHT IS LIKELY ON SATURDAY. SUNDAY THROUGH FRIDAY... MARINE CONDITIONS REMAIN QUIET THROUGH THE LONG TERM PERIOD AT THIS TIME. HIGH PRESSURE OVER THE GULF SHIFT EAST WEAKENING PRESSURE GRADIENT ALONG THE COASTLINE. EXPECT A LIGHT EASTERLY FLOW THROUGH THE WEEK WITH LIGHT TO MODERATE SEAS. ISOLATED SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP SUNDAY AFTERNOON THROUGH TUESDAY. FIRE WEATHER...ANOTHER DAY OF ENHANCED FIRE DANGER IS POSSIBLE ON SATURDAY. AFTERNOON MIN RH VALUES SHOULD BE A LITTLE HIGHER THAN FRIDAY...AND WINDS ARE EXPECTED TO REMAIN BELOW CRITICAL THRESHOLDS. HOWEVER PERSISTENT SOUTHEAST WINDS AND LOW RH MAY COMBINE WITH DRY FUELS...ESPECIALLY ALONG AND JUST WEST OF THE HIGHWAY 281 CORRIDOR TO CREATE ELEVATED FIRE GROWTH POTENTIAL ON SATURDAY AFTERNOON. && .BRO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ |
| #531613 (Received by flhurricane at: 7:56 PM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 730 PM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TONIGHT AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 615 PM FRI...UPDATED TO DROP POPS OVER LAND AREAS REST OF EVENING...EXCEPT LEFT ISOLATED MENTION ALONG OUTER BANKS. CONVECTIVE ACTIVITY HAS MOVED N OF AREA EXCEPT FOR ISOLATED ACTIVITY OFF COAST...AND NO SIGNS OF ADDITIONAL DEVELOPMENT INLAND REST OF TONIGHT. WENT WITH MOSTLY CLEAR SKIES THIS EVENING BASED ON LATEST STLT OBS AND TRENDS...WILL LEAVE PC OVERNIGHT FOR PSBL CONVECTIVE DEBRIS FROM W. NO CHANGES FOR TEMPS. /PREVIOUS DISCUSSION/ AS OF 345 PM FRI...CONVECTION THAT BEGAN ALONG A WEAK CONVERGENCE LINE FROM PENDER COUNTY NORTH TO GREENE COUNTY EARLIER TODAY HAS MOVED OFF TOWARDS BEAUFORT AND MARTIN COUNTIES...AND HAS WEAKENED. HAVE TEMPERED BACK POPS TO REFLECT LATEST RADAR TRENDS. TEMPS AND DEWPOINTS ARE FAIRLY CLOSE TO LATEST OBS TO NO CHANGES NEEDED. LATEST MSAS ANALYSIS INDICATES A WEAK UPPER LEVEL VORTMAX ACROSS EASTERN NC MIGRATING NORTH...ASSOCIATED WITH A WEAK UPPER LOW WHICH WILL GRADUALLY LIFT OUT TO THE NORTH TONIGHT. EXPECT SCATTERED TSTMS TO CONTINUE PROGRESSING NE SLOWLY...THEN WANE THIS EVENING WITH LOSS OF DAYTIME HEATING. OVERNIGHT SHOULD SEE DIMINISHING SHOWERS AND THUNDERSTORMS INLAND WITH WIDELY SCATTERED SHOWERS AND TSTMS POSSIBLE OFF THE COAST. SW FLOW WILL KEEP TEMPS MILD OVERNIGHT WITH LOWS IN THE LOW 70S INLAND TO MID/UPPER 70S ALONG THE COAST. && .SHORT TERM /SATURDAY/... AS OF 340 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON HOURS. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL SHOWERS AND THUNDERSTORMS. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 00Z SUNDAY/... AS OF 730 PM FRI...VFR CONDITIONS EXPTECTED DURING TAF PERIOD EXCEPT FOR PERIOD OF MVFR VSBYS OVERNIGHT. SCT CONVECTIVE ACTIVITY HAS MOVED N OF AREA AND NO ADDITIONAL DEVELOPMENT EXPECTED OVERNIGHT. GUIDANCE SUGGEST FOG FORMATION OVERNIGHT GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER. ONLY MINOR MVFR HAS BEEN OBSERVED RECENTLY SO HEDGED TOWARDS CLIMO OF RECENT NIGHTS AND KEPT LOW MVFR FOR FOG OVERNIGHT. SAT WILL SEE CONTINUED S FLOW WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/ AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH LOCALLY LOWER CEILINGS/VISIBILITIES. && .MARINE... SHORT TERM /THROUGH SATURDAY/... AS OF 615 PM FRI...NO CHANGES WITH UPDATE. /PREVIOUS DISCUSSION/ AS OF 330 PM FRI...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE SOUTHERLY WINDS 8-12 KNOTS WITH MEDIUM PERIOD SWELLS 2-3 FEET AT 8-9 SECONDS. GOOD BOATING CONDITIONS ARE EXPECTED THROUGH SAT WITH LIGHT S/SW WINDS. WAVEWATCH AND LOCAL SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TONIGHT THROUGH SATURDAY. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/ AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND. THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DAG |
| #531612 (Received by flhurricane at: 7:44 PM 03.Aug.2012) AFDCRP AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 640 PM CDT FRI AUG 3 2012 .DISCUSSION...UPDATED FOR 00Z AVIATION. && .AVIATION...VFR CONDITIONS WILL PREVAIL AT THE TERMINALS THROUGH THE TAF CYCLES. SOUTHEAST WINDS WILL SUBSIDE AT ALI/CRP/VCT BY 02Z BUT PICK UP AND PERHAPS BE A LITTLE GUSTY AT LRD THROUGH THE EVENING. ANTICIPATE SIMILAR CONDITIONS TOMORROW AS SOUTHEAST WINDS INCREASE AS THE SEA BREEZE MOVES INLAND. THERE MAY BE ENOUGH MOISTURE ON SATURDAY TO TRIGGER ISOLATED CONVECTION ALONG THE SEA BREEZE. HOWEVER...WILL NOT MENTION IN THE TAFS ATTM DUE TO LOW CONFIDENCE IN STORMS DEVELOPING. && .PREV DISCUSSION... /ISSUED 245 PM CDT FRI AUG 3 2012/ SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...MID/UPPER LEVEL HIGH PRESSURE CONTINUES TO DOMINATE OUR WEATHER PATTERN THROUGH THE START OF THE WEEKEND. WILL CONTINUE WITH AN OVERALL PERSISTENT FORECAST AS AFTERNOON TEMPERATURES REACH INTO THE TRIPLE DIGITS ALONG AND WEST OF HIGHWAY 281. MOISTURE VALUES INCREASE A BIT ACROSS THE REGION OVERNIGHT INTO SATURDAY...THUS WILL MAINTAIN THE MENTION OF PRECIPITATION FOR MORNING SHOWERS OVER THE WATERS...AND SLIGHT CHANCE OF CONVECTION DURING THE AFTERNOON. HOWEVER...ANY ACTIVITY WILL BE VERY ISOLATED IN NATURE AS SUBSIDENCE REMAINS IN PLACE AND THERE IS NO MAJOR FOCUS FOR LIFT. OVERNIGHT CONDITIONS WILL CONTINUE WARM AND MUGGY THROUGH THE FORECAST PERIOD AS WELL. LONG TERM (SUNDAY THROUGH FRIDAY)...CONCUR WITH THE GFS/ECMWF THAT THE UPPER RIDGE WILL RETROGRADE TOWARD THE NW DRG THE PERIOD. THUS...SUBSIDENCE EXPECTED TO DECREASE OVER THE CWA/MSA. FURTHER... CONCUR WITH THE GFS/NAM THAT A REGION OF GREATER MSTR...CURRENTLY OVER THE CNTRL GULF...WILL ENTER THE CWF/MSA EARLY IN THE PERIOD. THE COMBINATION OF THE FOREGOING/AFTN INSTABILITY (GFS CAPE/CIN) WILL CONTRIBUTE TO AT LEAST ISOLD CONVECTION. ANTICIPATE CONVECTION TO CONTINUE DRG THE PERIOD YET WITH THE GREATEST CHANCE OVER THE ERN CWA/MSA TUESDAY-WEDNESDAY. (EXPECT CONVECTION OVER THE COASTAL WATERS TO BE PRIMARILY NOCTURAL.) EXPECT MAX TEMPS TO FALL ONLY SLIGHTLY MONDAY-WEDNESDAY OWING TO GREATER MSTR...YET AT LEAST 100-105F MAX HEAT INDEX VALUES. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 78 97 78 96 78 / 10 10 10 20 10 VICTORIA 75 95 75 96 75 / 10 20 10 30 10 LAREDO 79 104 79 103 79 / 0 10 0 10 10 ALICE 76 102 76 99 76 / 10 10 10 20 10 ROCKPORT 80 91 80 90 81 / 10 20 10 30 10 COTULLA 76 103 75 102 75 / 0 10 0 10 10 KINGSVILLE 77 100 77 99 76 / 10 10 10 20 10 NAVY CORPUS 80 91 80 89 81 / 10 10 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531610 (Received by flhurricane at: 7:39 PM 03.Aug.2012) AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 700 PM EDT FRI AUG 3 2012 .SYNOPSIS... AN AREA OF HIGH PRESSURE IN THE WESTERN ATLANTIC WILL REMAIN IN PLACE THROUGH SATURDAY. A COLD FRONT IS THEN SCHEDULED TO ARRIVE LATE SUNDAY, BEFORE SLOWLY SHIFTING EASTWARD MONDAY. THIS FRONT MAY STALL NEARBY BEFORE A SECONDARY COLD FRONT ARRIVES WEDNESDAY INTO THURSDAY. THIS FRONT MAY THEN DISSIPATE AS YET ANOTHER COLD FRONT ARRIVES LATE THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AT 645 PM, A WEAKEN COMPLEX OF THUNDERSTORMS SPANNED PARTS OF BUCKS COUNTY, MERCER COUNTY AND NORTHERN BURLINGTON COUNTY. WITH THE LOSS OF DAYTIME HEATING, THE THUNDERSTORMS SHOULD CONTINUE TO WEAKEN SLOWLY. AS A SURFACE BOUNDARY LIFTS THROUGH NORTHERN NEW JERSEY, THE LEHIGH VALLEY AND THE POCONOS THIS EVENING, ISOLATED SHOWERS REMAIN POSSIBLE IN THOSE AREAS WITH PERHAPS A FEW FLASHES OF LIGHTNING. LOCATIONS FROM READING, PHILADELPHIA AND SEASIDE HEIGHTS SOUTHWARD SHOULD REMAIN PRECIPITATION FREE FOR THE BALANCE OF THE EVENING AND OVERNIGHT. THE THUNDERSTORMS KNOCKED TEMPERATURES DOWN INTO THE 80S IN THE PHILADELPHIA METROPOLITAN AREA. AS A RESULT, THE HEAT ADVISORY WAS CANCELLED. WITH PLENTY OF LOW LEVEL MOISTURE IN THE REGION, PATCHY FOG AND STRATUS IS POSSIBLE LATE TONIGHT, ESPECIALLY IN AREAS THAT HAVE RECEIVED RAINFALL. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... THE BERMUDA HIGH REMAINS TO THE EAST OF THE AREA AND WILL CONTINUE TO INFLUENCE OUR WEATHER. HOT HUMID AIR MASS REMAINS ACROSS THE REGION WITH A SOUTHERLY FLOW BECOMING A BIT MORE TO THE SOUTHEAST THROUGH THE DAY. WINDS START TO PICK UP LATER IN THE DAY AS LOW PRESSURE STARTS TO PUSH EASTWARD, CREATING A TIGHTER PRESSURE GRADIENT ACROSS OUR AREA. TEMPERATURES SHOULD REACH INTO LOWER 90S ACROSS MOST OF THE AREA WITH SOME UPPER 80S IN THE HIGHER TERRAIN OF NORTHWESTERN NEW JERSEY AND SOUTHERN POCONOS. DEWPOINTS WILL BE SIMILAR TO FRIDAYS AND BE IN THE UPPER 60S TO LOWER 70S. WHILE THIS WILL KEEP IT FEELING HUMID OUTSIDE, HEAT INDEX VALUES LOOK TO FALL SHORT OF ADVISORY LEVELS SO WE ARE NOT EXTENDING ANY HEAT HEADLINES WITH THIS PACKAGE. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE OVERALL SYNOPTIC PATTERN IS COMPRISED OF A ROBUST SHORT WAVE TROUGH THAT WILL MOVE FROM THE MIDWEST SATURDAY NIGHT TO THE NORTHEAST SUNDAY NIGHT INTO MONDAY. GIVEN THE STRENGTH OF THIS FEATURE, LOCALLY STRONG TO POTENTIALLY SEVERE CONVECTION MAY OCCUR LATER SUNDAY. THIS SHORT WAVE TROUGH THEN LOOKS TO WEAKEN SOME AS A LARGER TROUGH BECOMES ESTABLISHED ACROSS EASTERN CANADA AND A RIDGE PERSISTS IN THE SOUTHWESTERN ATLANTIC. THIS TROUGH THEN TENDS TO SETTLE SOUTHWARD SOME FROM THE MIDWEST TO THE NORTHEAST. THE OVERALL FLOW THOUGH MAY WEAKEN AS THE MAIN TROUGH WEAKENS NORTHEASTWARD, WHICH MAY END UP LEADING TO A COUPLE OF SURFACE COLD FRONTS SLOWING OR STALLING NEAR OUR REGION FROM LATE MONDAY ONWARD. WE USED MOSTLY A MODEL BLEND APPROACH FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT, THEN FOLLOWED FAIRLY CLOSELY TO HPC GUIDANCE THEREAFTER. HPC USED A GFS/ECMWF BLEND TO WEDNESDAY THEN AN EVEN BLEND OF THE ENSEMBLE MEAN AND NAEFS MEAN FOR THURSDAY AND FRIDAY. FOR SATURDAY NIGHT, ANY ISOLATED TO SCATTERED CONVECTION SHOULD DISSIPATE DURING THE EVENING HOURS AS IT SHOULD BE MOSTLY DRIVEN BY AIR MASS HEATING. THIS SCENARIO LOOKS TO FAVOR ANY CONVECTION TENDING TO HOLD INLAND AND ESPECIALLY FROM INTERSTATE 95 WESTWARD. OTHERWISE, A MUGGY NIGHT WITH SOME LINGERING MAINLY MID TO HIGH LEVEL CLOUDS. GIVEN THE AMOUNT OF LOW-LEVEL MOISTURE FORECAST TO BE IN PLACE ALONG WITH A LIGHT SOUTHERLY FLOW, PERHAPS SOME PATCHY STRATUS DEVELOPS. A ROBUST SHORT WAVE TROUGH WILL THEN START TO APPROACH LATE, AND SOME LOW-LEVEL WAA MAY ALLOW FOR A SMALL CHC FOR CONVECTION TO REDEVELOP OVERNIGHT. OUR CONFIDENCE IN THIS IS LOW GIVEN THE MAIN ASCENT HOLDING BACK WELL TO OUR WEST. FOR SUNDAY AND MONDAY, THIS LOOKS TO POTENTIALLY FEATURE A PERIOD OF ACTIVE CONVECTIVE WEATHER /SUNDAY/. A RATHER ROBUST SHORT WAVE TROUGH WILL BE WORKING EASTWARD FROM THE GREAT LAKES, HOWEVER THE TIMING OF THIS FEATURE LOOKS SLOW ENOUGH TO THROTTLE BACK/DELAY THE POPS SOME FROM WEST TO EAST. THE MODEL GUIDANCE INDICATES A DECENT LOW TO MID LEVEL WIND FIELD ARRIVING FROM THE WEST, ALTHOUGH THE STRONGER SHEAR IS FORECAST TO SLIDE MOSTLY TO OUR WEST AND NORTH AS THE UPPER-LEVEL TROUGH AXIS LIFTS NORTHEASTWARD A BIT. THE GUIDANCE INDICATES THAT PLENTY OF INSTABILITY WILL BE IN PLACE ACROSS OUR AREA, AND WITH AMPLE HEATING TAKING PLACE A PRE-FRONTAL TROUGH SHOULD SET UP. THIS MAY PROVIDE ENOUGH LOW- LEVEL CONVERGENCE FOR ISOLATED TO SCATTERED CONVECTION TO DEVELOP. IT LOOKS HOWEVER THAT WE WILL HAVE TO WAIT FOR THE MAIN ASCENT WITH THE UPPER-LEVEL TROUGH TO ARRIVE TO FORCE MORE ORGANIZED CONVECTION, WHICH MAY TEND TO BE IN THE FORM OF CLUSTERS AND/OR LINE SEGMENTS. THIS TIMING WOULD TEND TO BRING THIS INTO OUR WESTERN ZONES IN THE AFTERNOON AND THEN DURING THE NIGHT ACROSS OUR EASTERN AND SOUTHERN ZONES. WHILE THE CONVECTION MAY WEAKEN DURING THE OVERNIGHT, INSTABILITY HOLDING ON ALONG WITH THE PASSAGE OF THE UPPER-LEVEL TROUGH AND SURFACE COLD FRONT SHOULD BE ENOUGH TO SUSTAIN AT LEAST SOME CONVECTION. GIVEN THE INSTABILITY AND THERMODYNAMIC PROFILES /RELATIVELY HIGH MOISTURE CONTENT AND STEEPENING LOW-LEVEL LAPSE RATES/, SOME OF THE CONVECTION MAY BECOME SEVERE ESPECIALLY IF STORMS CAN INITIATE EARLIER. IN ADDITION, THE SEVERE THREAT MAY TEND TO INCREASE IF ORGANIZED COLD POOLS WITHIN LINE SEGMENTS OR CLUSTERS CAN BECOME ESTABLISHED WHICH WOULD ENHANCE THE DOWNBURST WIND POTENTIAL. THEREFORE, LOCALLY GUSTY TO DAMAGING WINDS LOOK TO BE THE MAIN THREAT. IF STORMS ARE ABLE TO SUSTAIN STRONG UPDRAFTS, THEN LARGER HAIL WOULD ALSO BECOME A CONCERN. DESPITE THE POTENTIAL FOR A LATER ARRIVAL, THERE IS AT LEAST SOME STRONG CONVECTIVE WIND POTENTIAL THEREFORE ADDED GUSTY WINDS IN THE FORECAST. GIVEN A RATHER MOIST AND UNSTABLE AIR MASS, ROBUST ENOUGH UPDRAFTS MAY PRODUCE A LOT OF LIGHTNING, THEREFORE ADDED THIS AS WELL. WE WILL ALSO CONTINUE THE MENTION OF POSSIBLE STRONG TO SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK. BASED ON THE MODEL CONSENSUS, WE SLOWED DOWN THE POP INCREASE FROM WEST TO EAST A DECENT AMOUNT. THE COLD FRONT THEN GRADUALLY SLIDES SOUTHEASTWARD MONDAY WITH SOME SHOWERS AND STORMS POSSIBLY LINGERING MAINLY ACROSS OUR EASTERN AND SOUTHERN ZONES THROUGH MIDDAY. THERE MAY BE ENOUGH OF A SOUTHEASTERLY PUSH FROM AN INCOMING SURFACE HIGH TO REDUCE THE CONVECTIVE THREAT THE FARTHER NORTHWEST ONE GOES ACROSS OUR CWA. AS A RESULT, WE SHAVED THE POPS BACK FROM NORTHWEST TO SOUTHEAST WITH TIME. THE DRIER AIR HOWEVER MAY BE DELAYED IN ARRIVING ACROSS THE BULK OF OUR CWA AS THE SURFACE FRONT MAY TEND TO SLOW OR EVEN STALL. FOR TUESDAY AND WEDNESDAY, AN UPPER-LEVEL TROUGH GENERALLY BECOMES MORE AND MORE ESTABLISHED ACROSS THE NORTHEAST. THIS SHOULD FAVOR THE AFOREMENTIONED COLD FRONT STALLING NEAR THE NORTHERN MID ATLANTIC REGION. THIS BOUNDARY LOOKS TO WASH OUT WITH TIME AS SOME TROUGH AMPLIFICATION OCCURS UPSTREAM AND SENDS A SECONDARY COLD FRONT OUR WAY WEDNESDAY. SOME LOWERING HEIGHTS ALOFT ONCE AGAIN COMBINED ESPECIALLY WITH HEATING AND TERRAIN AFFECTS MAY BE ENOUGH TO ALLOW FOR ISOLATED TO SCATTERED SHOWERS AND STORMS ESPECIALLY WEDNESDAY AFTERNOON AND EVENING. FOR NOW, WE LEANED MORE TOWARD SLIGHT CHC POPS AS COVERAGE LOOKS TO BE LIMITED. FOR THURSDAY AND FRIDAY, AS THE UPPER-LEVEL TROUGH IS MAINTAINED IN THE NORTHEAST, ADDITIONAL ENERGY ROUNDING ITS BASE MAY KEEP THE SURFACE FRONTS SLOW MOVING OR EVEN STALL INTO THE MID ATLANTIC. A LEE SIDE TROUGH MAY BECOME PRESENT DURING BOTH OF THESE DAYS BEFORE ANOTHER SURFACE COLD FRONT ARRIVES LATE THURSDAY AND FRIDAY. THE OVERALL TROUGHING/CYCLONIC FLOW ABOVE SURFACE HEATING MAY LEAD TO SOME MAINLY DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. THE MAIN FORECAST CHALLENGE THIS FAR OUT IS MOSTLY COVERAGE. GIVEN LOWER CONFIDENCE, WENT WITH SLIGHT CHC TO LOW CHC POPS. AS FOR TEMPERATURES, WE USED MOSTLY A MOS BLEND FOR SATURDAY NIGHT THROUGH MONDAY THEN CLOSER TO HPC GUIDANCE. SOME ADJUSTMENTS WERE THEN MADE AFTER SOME ADDITIONAL COLLABORATION. SUNDAY LOOKS TO BE ANOTHER VERY WARM TO HOT DAY, HOWEVER HEAT INDICES ATTM LOOK TO STAY BELOW ADVISORY CRITERIA EVEN FOR THE PHILADELPHIA METRO AREA. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. MAINLY VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING. ISOLATED CONVECTION WILL CONTINUE TO DIMINISH. WINDS WILL REMAIN LIGHT AND OUT OF A SOUTHERLY DIRECTION TONIGHT. WINDS SHOULD GO LIGHT AND VARIABLE AT MOST LOCATIONS OVERNIGHT. WHERE IS WIND, IT WILL BE A SLIGHT SOUTHWEST FLOW BECOMING MORE SOUTHEASTERLY TOWARD SATURDAY MORNING. FOG WILL ONCE AGAIN BE AN ISSUE TO DEAL WITH SATURDAY MORNING. PLENTY OF LOW LEVEL MOISTURE WILL REMAIN ACROSS THE REGION AND THE POTENTIAL FOR MVFR, POSSIBLY IFR, FOG WILL EXIST. FOG WILL BE MORE LIKELY IN LOCATIONS WHERE RAIN FALLS. OUTLOOK... SATURDAY NIGHT THROUGH SUNDAY...GENERALLY VFR /SMALL CHANCE FOR POCKETS OF STRATUS LATER SATURDAY NIGHT AND SUNDAY MORNING/, WITH ANY ISOLATED OR SCATTERED THUNDERSTORMS ENDING BY LATE SATURDAY EVENING. THEN, A BETTER CHANCE OF SOME SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON AND SUNDAY NIGHT AS A COLD FRONT SLOWLY ARRIVES. SOME OF THE STORMS MAY BE GUSTY ALONG WITH LOCAL SUB-VFR CONDITIONS FOR A TIME. A GENERAL SOUTH TO SOUTHWEST WIND SUNDAY AFTERNOON MAY GUST TO ABOUT 20 KNOTS. MONDAY AND TUESDAY...SOME SCATTERED SHOWERS OR THUNDERSTORMS MAY LINGER ESPECIALLY THROUGH MIDDAY MONDAY WITH LOCAL SUB-VFR POSSIBLE. OTHERWISE, VFR WITH ANOTHER LOW CHANCE OF A THUNDERSTORM TUESDAY AFTERNOON MAINLY SOUTH OF A LINE FROM KILG TO KACY. WEDNESDAY...A LOCAL SHOWER OR THUNDERSTORM IS POSSIBLE AS A SECONDARY COLD FRONT SLOWLY ARRIVES. && .MARINE... SEAS AND WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH SATURDAY. HOWEVER, WITH THE GRADIENT STARTING TO TIGHTEN UP, AN INCREASING SOUTHEASTERLY FLOW WILL DEVELOP TOWARD SATURDAY AFTERNOON AND EVENING, INCREASING WINDS AND SEAS SLIGHTLY. OUTLOOK... HIGH PRESSURE CENTERED TO OUR SOUTHEAST WILL ERODE SOME SUNDAY INTO MONDAY AS A COLD FRONT ARRIVES. A SOUTHERLY FLOW AHEAD OF THIS FRONT IS EXPECTED TO INCREASE SUNDAY INTO MONDAY AS THE PRESSURE GRADIENT TIGHTENS. THIS MAY RESULT IN ADVISORY LEVEL WIND GUSTS OCCURRING LATE SUNDAY AFTERNOON AND ESPECIALLY SUNDAY NIGHT. THESE WINDS ARE THEN EXPECTED TO DIMINISH MONDAY. THE INCREASED SOUTHERLY FLOW WILL ALSO BUILD THE SEAS, WHERE HEIGHTS MAY GET TO AROUND 5 FEET ON THE OCEAN SUNDAY NIGHT BEFORE GRADUALLY SUBSIDING MONDAY. SOME THUNDERSTORMS SUNDAY NIGHT MAY BE LOCALLY GUSTY ALONG WITH FREQUENT LIGHTNING. THE CONDITIONS ARE EXPECTED TO BE BELOW ADVISORY CRITERIA TUESDAY AND WEDNESDAY. && .RIP CURRENTS... THE MODERATE RISK OF RIP CURRENTS FOR NEW JERSEY AND LOW FOR DELAWARE CONTINUES THROUGH THIS EVENING. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ |
| #531608 (Received by flhurricane at: 7:33 PM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 710 PM EDT FRI AUG 3 2012 .SYNOPSIS... A VERY WARM AND HUMID WEEKEND ALONG WITH MAINLY DRY WEATHER IS ON TAP. A COLD FRONT WILL BRING A ROUND OF SHOWERS AND THUNDERSTORMS...MAINLY SUN NIGHT INTO EARLY MON. DRY WEATHER FOLLOWS FOR THE MIDDLE OF NEXT WEEK...WITH PERHAPS A FEW MORE SHOWERS/THUNDERSTORMS NEXT THU AND/OR FRI. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... 710 PM UPDATE... A COUPLE OF ISOLATED THUNDERSTORMS REMAINED TO THE NORTH AND WEST OF OUR COUNTY WARNING AREA EARLY THIS EVENING. GIVEN THE LACK OF FORCING/WIND SHEAR AS WELL AS THE LOSS OF DAYTIME HEATING...ODDS FOR CONVECTION DEVELOPING OR MAKING IT INTO OUR REGION ARE QUITE LOW. HAVE GONE WITH A DRY FORECAST TONIGHT...ALTHOUGH WE CAN/T COMPLETELY RULE OUT A VERY REMOTE SHOWER OVER THE NEXT HOUR OR TWO. OTHERWISE...PATCHY FOG/STRATUS WILL LIKELY REDEVELOP LATER TONIGHT ALONG THE SOUTH COAST AND IN THE INTERIOR VALLEYS. && .SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/... SAT... TRICKY FORECAST TOMORROW AS ALL MODEL GUIDANCE /TO VARYING DEGREES/ HAS QPF ACROSS THE AREA AND THEN LIFTING NORTHWARD WITH TIME. THIS SEEMS SOMEWHAT REASONABLE AS WEAK SURFACE TROUGH LIFTS NORTH AS A WARM FRONT. SO THIS BOUNDARY COULD PROVIDE A FOCUS FOR CONVECTION. HOWEVER PATTERN RECOGNITION WOULD SUGGEST A CAPPED ENVIRONMENT WITH RISING MID LEVEL HEIGHTS AS SUBTROPICAL RIDGE BUILDS NORTHWEST INTO SOUTHERN NEW ENGLAND. IN ADDITION MID LEVEL FLOW IS ANTICYCLONIC PROVIDING SUBSIDENCE. MOS POPS REFLECT THIS IDEA WITH ONLY SLIGHT CHC POPS FROM THE METNAM AND MAVGFS. THUS WILL GO WITH SLIGHT CHANCE POPS. GIVEN THE LACK OF DEEP LAYER SHEAR THE MAIN RISK WITH ANY TSTM WILL BE BRIEF HEAVY RAIN. MUCH OF THE DAY SHOULD BE DRY ALONG WITH VERY WARM AND HUMID CONDITIONS CONTINUING. SAT NIGHT... MAINLY WARM...MUGGY AND DRY BUT A LOW RISK OF SHOWERS/TSTMS TOWARD SUNDAY MORNING AS MID LEVEL FLOW BECOMES CYCLONIC WITH APPROACHING SHORT WAVE TROUGH. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGHLIGHTS... *SHOWERS/STORMS LIKELY SUN NIGHT AND/OR EARLY MON WITH HEAVY RAINFALL *SEASONABLE AND MAINLY DRY WEATHER FOR THE MIDDLE OF NEXT WEEK *A FEW SHOWERS/STORMS POSSIBLE AGAIN BY LATE NEXT WEEK DETAILS... SUNDAY AND MONDAY... LOW CONFIDENCE ON TIMING OF THE BULK OF THE PRECIPITATION AS CONSIDERABLE MODEL DIFFERENCES REMAIN. EXPECT MUCH OF THE DAYLIGHT HOURS TO BE DRY ON SUNDAY...OTHER THAN PERHAPS A FEW BRIEF SPOT SHOWERS/THUNDERSTORMS. THE BULK OF THE ACTIVITY SHOULD ARRIVE SOMETIME SUNDAY NIGHT AND POSSIBLY INTO EARLY MONDAY AHEAD OF THE COLD FRONT. THE MAIN CONCERN WITH THIS ACTIVITY WILL BE HEAVY RAINFALL/LOCALIZED FLOODING GIVEN PWATS ON THE ORDER OF 2 TO 2.5 INCHES. SEVERE WEATHER POTENTIAL LOOKS LOW GIVEN WEAK MID LEVEL LAPSE RATES AND AN UNFAVORABLE TIME OF ARRIVAL. HOWEVER...CAN/T COMPLETELY RULE OUT A FEW STRONG THUNDERSTORMS. TUESDAY AND WEDNESDAY... A WEAK RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE COLD FRONT. DRY WEATHER SHOULD DOMINATE OVER THIS TIME ALONG WITH FAIRLY SEASONABLE TEMPERATURES. THURSDAY AND FRIDAY... UPPER LEVEL TROUGH/COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS WILL BRING THE CHANCE OF A ROUND OR TWO OF SCATTERED SHOWERS/THUNDERSTORMS...BUT LOW CONFIDENCE ON TIMING. ALSO...NOT EXPECTING A WASHOUT AS MUCH OF THE TIME WILL PROBABLY FEATURE DRY WEATHER. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW... TONIGHT...CONFIDENCE IS LOW ON IFR CEILINGS REDEVELOPING. CURRENT THINKING IS THAT MOST OF IT WILL BE CONFINED TO PORTIONS OF THE SOUTH COAST/CAPE COD/ISLANDS. HOWEVER...AREAS OF PATCHY FOG WILL LIKELY RESULT IN LOCALIZED MVFR-IFR CONDITIONS LATE ACROSS OTHER AREAS. SAT...ANY IFR CAPE COD AND ISLANDS WILL BURN OFF BY MIDDAY. OTHERWISE VFR WITH JUST A LOW PROB OF AN ISOLATED TSTM IN THE AFTN. KBOS TAF...HIGH CONFIDENCE. MAINLY VFR TONIGHT AND SATURDAY. HOWEVER...BRIEF MVFR VISIBILITIES ARE POSSIBLE EARLY SAT. VERY LOW PROB OF AN ISOLATED TSTM SAT AFTN. KBDL TAF...MODERATE TO HIGH CONFIDENCE. MAINLY VFR CONDITIONS TONIGHT AND SATURDAY...ALTHOUGH A PERIOD OF MVFR VISIBILITIES ARE LIKELY LATE TONIGHT/EARLY SAT IN FOG. VERY LOW PROB OF AN ISOLATED TSTM SAT AFTN. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN LOW CLOUDS AND FOG EARLY SUN WILL PROBABLY TEMPORARILY IMPROVE. HOWEVER...MVFR-IFR CONDITIONS SHOULD OCCUR AGAIN SUN NIGHT/EARLY MON IN SOME SHOWERS/THUNDERSTORMS. TUESDAY AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE IN MAINLY VFR CONDITIONS. && .MARINE... TONIGHT... THINK ANY TSTMS ACROSS NORTHERN NEW ENGLAND WILL DISSIPATE BEFORE REACHING THE SOUTH COAST. OTHERWISE DRY WEATHER SHOULD PREVAIL BUT LOW CLOUDS AND FOG MAY REDEVELOP LATER TONIGHT RESULTING IN A RISK FOR PATCHY DENSE FOG. ALTHOUGH FORECAST CONFIDENCE IS LOW ON AREAL COVERAGE. LIGHT S-SW WINDS PREVAIL. NOT MUCH WIND WAVE OR SWELL. SAT... LIGHT SSW WINDS CONTINUE. NOT MUCH WIND WAVE OR SWELL EXPECTED. VSBY MAY BE REDUCED IN PATCHY DENSE FOG DURING THE MORNING. CONFIDENCE IS LOW ON AREAL EXTENT BUT ANY FOG SHOULD BURN OFF BY MIDDAY. VERY LOW RISK OF A SHOWER/TSTM BUT MUCH OF THE DAY SHOULD BE DRY. SAT NIGHT... MORE OF THE SAME...LIGHT BUT MOIST SSW WINDS YIELDING PATCHY DENSE FOG LATE. OUTLOOK...SUNDAY THROUGH WEDNESDAY... MODERATE TO HIGH CONFIDENCE. SUNDAY AND MONDAY... INCREASING SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL BUILD SEAS TO ABOVE SCA THRESHOLDS ACROSS THE SOUTHERN WATERS LATE SUN THROUGH MON NIGHT. IN ADDITION...WIND GUSTS OF 20 TO 25 KNOTS CAN BE EXPECTED. THE OTHER BIG CONCERNS FOR MARINERS WILL BE AREAS OF FOG AND THE POTENTIAL FOR SOME THUNDERSTORMS SUN NIGHT INTO MON. TUESDAY AND WEDNESDAY... ANY LINGERING SCA FOR SEAS SHOULD DIMINISH ACROSS THE SOUTHERN WATERS DURING THE DAY TUE. OTHERWISE...RELATIVELY WEAK PRESSURE GRADIENT SHOULD KEEP WINDS AND SEAS BELOW SCA THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ004>006- 009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...NOCERA/FRANK |
| #531607 (Received by flhurricane at: 7:20 PM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 705 PM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL INTO EARLY NEXT WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A STATIONARY FRONT WILL STALL NORTH OF THE AREA MID TO LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... ISOLATED SHOWERS/THUNDERSTORMS WILL DEVELOP ALONG MESOSCALE BOUNDARIES ACROSS INLAND COUNTIES INTO THIS EVENING. THEN...DIURNAL PRECIPITATION WILL DISSIPATE BEFORE MIDNIGHT. GIVEN DOWNDRAFT CAPES EXCEEDING 1200 J/KG CANNOT COMPLETELY RULE OUT A BRIEF PULSE SEVERE THUNDERSTORM WITH DAMAGING WINDS WHERE BOUNDARY INTERACTIONS OCCUR...BUT AFTERNOON/EVENING CONVECTIVE TRENDS AND ASSOCIATED PARAMETERS SUGGEST THAT THE POTENTIAL FOR SEVERE WEATHER WILL REMAIN GREATLY LIMITED THIS EVENING. LATE TONIGHT/EARLY SATURDAY...ONSHORE FLOW/LOCALIZED CONVERGENCE COULD SUPPORT ISOLATED SHOWERS/THUNDERSTORMS OVER COASTAL COUNTIES/ADJACENT COASTAL WATERS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... A DEEP LAYER RIDGE...STRETCHING FROM THE ATLANTIC...WESTWARD ACROSS THE SOUTHERN AND CENTRAL U.S....WILL PERSIST THROUGH THE PERIOD. A TROPICAL WAVE WELL SOUTH OF THE AREA OVER THE BAHAMAS...IS EXPECTED TO REMAIN SOUTH OF THE REGION AS IT MOVES WESTWARD ACROSS CENTRAL FLORIDA AND THEN INTO THE WESTERN GULF OF MEXICO BY EARLY NEXT WEEK. THE GLOBAL MODELS KEEP THIS TROPICAL WAVE WEAK...AND PUSH THE NORTHERN FRINGE OF THE ASSOCIATED MOISTURE ACROSS THE REGION SATURDAY AND SUNDAY...THEN WEST OF THE REGION BY LATER SUNDAY AND MONDAY. HOWEVER...THE NAM IS MUCH SLOWER WITH THE PROGRESSION OF MOISTURE ASSOCIATED WITH THIS TROPICAL WAVE. THE NAM BRINGS IN THE BEST MOISTURE ACROSS THE AREA LATE SATURDAY NIGHT...THEN PERSISTING THROUGH MONDAY. IF THE NAM IS MORE CORRECT...POPS WILL NEED TO BE RAISED FOR SUNDAY AND MONDAY. WILL CONTINUE TO MONITOR LATER NAM SOLUTIONS. FOR NOW...HAVE KEPT GENERALLY CLIMO /CHC/ POPS...CENTERED AROUND THE AFTERNOON/EVENING HEATING...BUT AS MENTIONED ABOVE...POPS MAY NEED TO BE NUDGED HIGHER IS DEEPER MOISTURE ASSOCIATED WITH THE NORTHERN FRINGE OF THE TROPICAL WAVE IMPACTS THE REGION THIS WEEKEND. SOUTHEAST LOW LEVEL FLOW SHOULD HELP TO FOCUS SCATTERED AFTERNOON/EVENING CONVECTION INLAND. WITH NO APPRECIABLE UPPER LEVEL FEATURES TO FORCE CONVECTION...EXPECT MESOSCALE BOUNDARIES AND SEA BREEZE TO BE THE PRIMARY FOCUS FOR CONVECTION. TEMPS EXPECTED TO NEAR NORMAL THROUGH THE PERIOD...HIGHS IN THE LOWER 90S AND LOWS IN THE MID 70S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL RIDGING WILL BEGIN TO WEAKEN EARLY NEXT WEEK...AS A TROUGH ALOFT AND SEVERAL SHORTWAVES MOVE ACROSS THE NEW ENGLAND STATES. AN ASSOCIATED COLD FRONT WILL LIKELY STALL WELL TO THE NORTH OF THE FORECAST AREA BY THE MIDDLE OF NEXT WEEK. AT THE SURFACE...THE INLAND TROUGH COULD BECOME MORE PROMINENT BETWEEN SURFACE HIGH PRESSURE OVER THE CENTRAL UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. CONSIDERING THE INCREASED FORCING FROM THE STALLED FRONT TO THE NORTH...COMBINED WITH INFLUENCES FROM THE LEE TROUGH AND BOUNDARY/SEABREEZE INTERACTIONS...CONVECTIVE POTENTIAL COULD BE GREATER THROUGH THE EXTENDED PERIOD. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS...WITH HIGH TEMPERATURES IN THE LOW TO MID 90S DURING THE AFTERNOON FALLING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... VFR THROUGH SATURDAY. THE PROBABILITY FOR THUNDERSTORMS IN THE VICINITY OF THE TERMINALS REMAINS TOO LOW TO JUSTIFY A MENTION WITHIN 00Z TAFS FOR SATURDAY AFTERNOON. EXTENDED AVIATION OUTLOOK...MAINLY VFR. ISOLATED AFTERNOON CONVECTION POSSIBLE EACH DAY...WITH BRIEF PERIODS OF SUB-VFR CONDITIONS POSSIBLE. && .MARINE... TONIGHT...S/SE WINDS WILL AVERAGE 10-15 KT WITH A FEW GUSTS TO 20 KT... THEN WINDS COULD DIMINISH SOMEWHAT FOR A TIME TOWARD DAYBREAK. SEAS WILL REMAIN 2-3 FT. A ATLANTIC RIDGE OF HIGH PRESSURE WILL REMAIN CENTERED JUST NORTH OF THE REGION THROUGH THE WEEKEND...THEN DRIFT SOUTHWARD OVER THE REGION MONDAY THROUGH WEDNESDAY. SOUTHEAST WINDS OF 15 KTS OR LESS AND SEAS 4 FT OR LESS EXPECTED THROUGH THE PERIOD. A WEAK TROPICAL WAVE IS EXPECTED TO MOVE WELL SOUTH OF THE REGION ACROSS CENTRAL FLORIDA THIS WEEKEND AND INTO EARLY NEXT WEEK. THERE COULD BE AN INCREASE OF SHOWERS AND THUNDERSTORMS BY LATER THIS WEEKEND AS THE MOISTURE ASSOCIATED WITH THIS WAVE GLANCES THE REGION. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531605 (Received by flhurricane at: 6:59 PM 03.Aug.2012) AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 653 PM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH SATURDAY/... 7PM UPDATE...UPDATED POP/WX/SKY FOR LATEST RADAR/SATELLITE TRENDS. ACTIVITY WILL CONTINUE TO DECREASE IN COVERAGE AND OVERALL INTENSITY AS THE SUN CONTINUES TO SET. PREV DISCUSSION... CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE. TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL. HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY. AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL BE LAST TO CLEAR DURING THE AFTERNOON. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT. DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE VFR. SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART. HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5 FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3 FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW. SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY DROPPING THEM BACK 1-2 FEET. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT/NRR |
| #531600 (Received by flhurricane at: 6:38 PM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 626 PM EDT FRI AUG 3 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL STALL OVER THE REGION TONIGHT... BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HOT AND HUMID CONDITIONS WILL CONTINUE TOMORROW AND SUNDAY. A STRONGER COLD FRONT WILL CROSS THE REGION LATE SUNDAY NIGHT OR MONDAY BRINGING ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE AREA. HIGH PRESSURE BUILDS OVER THE REGION MONDAY THROUGH WEDNESDAY WITH DRIER CONDITIONS EXPECTED. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... UPDATE...WILL TWEAK POPS A BIT AND ENTER OBSERVED TEMPS AND DEWPOINTS. PREV DISC...WEAK FRONTAL BOUNDARY APPROACHING THE AREA THIS AFTERNOON FROM THE NORTHWEST. VISIBLE SATELLITE IMAGERY SHOWS DECENT CLEARING ACROSS MOST OF THE FORECAST AREA. MODIFIED 12Z KGYX SOUNDING INDICATES UPWARDS OF 2500J/KG WORTH OF CAPE TO WORK WITH. ALTHOUGH SHEAR IS WEAK...EXPECT SOME SCATTERED STORMS TO DEVELOP THIS AFTERNOON AND EVENING. SOME MAY BE STRONG ENOUGH TO REACH SEVERE LIMITS...BUT THEY SHOULD BE PRETTY ISOLATED. ONCE DIURNAL HEATING FADES CONVECTION SHOULD DIE OFF PRETTY QUICKLY. WITH DEWPOINTS STILL WELL INTO THE 60S...EXPECT FOG TO SET UP AGAIN ACROSS MUCH OF THE AREA. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... FOG AND STRATUS SHOULD BURN OFF DURING THE MORNING HOURS TOMORROW. FRONTAL BOUNDARY STALLED TO OUR SOUTH WILL START TO MAKE ITS WAY NORTHWARD AS A WEAK WARM FRONT. NOT MUCH LEFT IN THE WAY OF DYNAMICS WITH THE BOUNDARY AND SHOWERS AND THUNDERSTORMS MAY BE LIMITED TO WESTERN PORTIONS OF CWA AND THE MOUNTAINS. EXPECT CLEARING GOING INTO SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... SOUTHERLY FLOW TRANSPORTS MORE MOISTURE INTO THE REGION ON SUNDAY IN ADVANCE OF AN APPROACHING TROUGH. WILL PROBABLY SEE FOG ALONG THE COAST WHICH MAY LAST INTO THE AFTERNOON ESPECIALLY ON THE MIDCOAST. OUTSIDE OF FOGGY AREAS... TEMPERATURES WILL WARM WELL INTO THE 80S. TIMING OF THE TROUGH AND ASSOCIATED COLD FRONT SEEM TO SUGGEST THAT PRECIPITATION WILL BE LATER IN ARRIVING. SHOULD SEE A CHANCE OF SHOWERS AND THUNDERSTORMS LATE SUNDAY AFTERNOON AND THROUGH SUNDAY NIGHT. THIS TIMING MEANS THE SEVERE WEATHER THREAT WILL BE MINIMIZED. HOWEVER... EVEN WITH THE PASSAGE DURING THE NIGHTTIME HOURS IN THE ABSENCE OF SURFACE BASED INSTABILITY... INSTABILITY ALOFT GENERATED BY THE TROUGH AND COLD ADVECTION ALOFT MAY BE ENOUGH TO KEEP THUNDERSTORMS GOING. SHEAR WOULD BE SUFFICIENT FOR SUPERCELLS AND BOWING MULTICELL STORMS GIVEN ENOUGH INSTABILITY. COLD FRONT MAKES A FULL PASSAGE THROUGH THE AREA BY MONDAY MORNING OR EARLY MONDAY AFTERNOON. MAY STILL SEE SOME SHOWERS AND STORMS LINGERING AHEAD OF THE FRONT THROUGH EARLY MONDAY. OTHERWISE WILL SEE A CLEARING AND DRYING TREND AS HIGH PRESSURE BUILDS IN FROM THE WEST. HIGH PRESSURE GENERALLY HOLDS THROUGH TUESDAY... ALTHOUGH A WEAK SHORTWAVE TROUGH CROSSES JUST NORTH OF THE INTERNATIONAL BORDER. ANOTHER SHORTWAVE TROUGH DIGS FURTHER SOUTH ON WEDNESDAY AND THURSDAY... WITH SHOWERS AND THUNDERSTORMS POSSIBLE PRIMARILY DURING THE AFTERNOON EACH DAY OVER INTERIOR LOCATIONS. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... SHORT TERM...EXPECT VFR CONDITIONS TO DETERIORATE TONIGHT TO IFR/LIFR CONDITIONS IN FOG. FOG WILL LIFT BY MID-MORNING TOMORROW WITH VFR CONDITIONS RETURNING AND REMAINING IN PLACE FOR THE REMAINDER OF THE SHORT TERM PERIOD. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...WILL PROBABLY SEE FOG RETURN SATURDAY NIGHT INTO EARLY SUNDAY ALONG THE COAST. FOG WILL LINGER LONGEST ALONG THE MIDCOAST NEAR ROCKLAND AND MAY EVEN LAST THROUGH THE AFTERNOON. EXPECT SHOWERS AND THUNDERSTORMS LATE SUNDAY THROUGH EARLY MONDAY. GENERALLY VFR AFTER THE COLD FRONT MOVES THROUGH ON MONDAY THROUGH THE MIDDLE OF THE WEEK. && .MARINE... SHORT TERM /THROUGH SATURDAY...A WEAK FRONT DROPS INTO THE GULF OF MAINE ON FRIDAY BEFORE DISSIPATING. WINDS AND SEAS SHOULD REMAIN FAIRLY QUIET. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...SOUTHERLY FLOW WILL INCREASE IN ADVANCE OF AN APPROACHING COLD FRONT ON SUNDAY. ALTHOUGH WINDS MAY STAY BELOW 25 KT... SEAS WILL GRADUALLY BUILD ON THE SOUTHERLY FETCH AND WAVE HEIGHTS MAY EXCEED 5 FEET. THE COLD FRONT WILL CROSS THE WATERS ON MONDAY WITH A RETURN TO MORE TRANQUIL CONDITIONS. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ |
| #531596 (Received by flhurricane at: 6:30 PM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 620 PM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TONIGHT AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 615 PM FRI...UPDATED TO DROP POPS OVER LAND AREAS REST OF EVENING...EXCEPT LEFT ISOLATED MENTION ALONG OUTER BANKS. CONVECTIVE ACTIVITY HAS MOVED N OF AREA EXCEPT FOR ISOLATED ACTIVITY OFF COAST...AND NO SIGNS OF ADDITIONAL DEVELOPMENT INLAND REST OF TONIGHT. WENT WITH MOSTLY CLEAR SKIES THIS EVENING BASED ON LATEST STLT OBS AND TRENDS...WILL LEAVE PC OVERNIGHT FOR PSBL CONVECTIVE DEBRIS FROM W. NO CHANGES FOR TEMPS. /PREVIOUS DISCUSSION/ AS OF 345 PM FRI...CONVECTION THAT BEGAN ALONG A WEAK CONVERGENCE LINE FROM PENDER COUNTY NORTH TO GREENE COUNTY EARLIER TODAY HAS MOVED OFF TOWARDS BEAUFORT AND MARTIN COUNTIES...AND HAS WEAKENED. HAVE TEMPERED BACK POPS TO REFLECT LATEST RADAR TRENDS. TEMPS AND DEWPOINTS ARE FAIRLY CLOSE TO LATEST OBS TO NO CHANGES NEEDED. LATEST MSAS ANALYSIS INDICATES A WEAK UPPER LEVEL VORTMAX ACROSS EASTERN NC MIGRATING NORTH...ASSOCIATED WITH A WEAK UPPER LOW WHICH WILL GRADUALLY LIFT OUT TO THE NORTH TONIGHT. EXPECT SCATTERED TSTMS TO CONTINUE PROGRESSING NE SLOWLY...THEN WANE THIS EVENING WITH LOSS OF DAYTIME HEATING. OVERNIGHT SHOULD SEE DIMINISHING SHOWERS AND THUNDERSTORMS INLAND WITH WIDELY SCATTERED SHOWERS AND TSTMS POSSIBLE OFF THE COAST. SW FLOW WILL KEEP TEMPS MILD OVERNIGHT WITH LOWS IN THE LOW 70S INLAND TO MID/UPPER 70S ALONG THE COAST. && .SHORT TERM /SATURDAY/... AS OF 340 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON HOURS. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL SHOWERS AND THUNDERSTORMS. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 12Z SATURDAY/... AS OF 145 PM FRI...MAINLY VFR CONDITIONS EXPECTED TODAY ALTHOUGH MAY SEE BRIEF MVFR IN REDUCED VSBYS AND CEILINGS DUE TO CONVECTION MAINLY FOR OAJ/EWN/ISO. GUIDANCE SUGGEST FOG FORMATION OVERNIGHT GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER. ONLY MINOR MVFR HAS BEEN OBSERVED RECENTLY SO HEDGED TOWARDS CLIMO OF RECENT NIGHTS AND KEPT LOW MVFR FOR FOG OVERNIGHT. SAT WILL SEE CONTINUED S FLOW WITH DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/ AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH LOCALLY LOWER CEILINGS/VISIBILITIES. && .MARINE... SHORT TERM /THROUGH SATURDAY/... AS OF 615 PM FRI...NO CHANGES WITH UPDATE. /PREVIOUS DISCUSSION/ AS OF 330 PM FRI...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE SOUTHERLY WINDS 8-12 KNOTS WITH MEDIUM PERIOD SWELLS 2-3 FEET AT 8-9 SECONDS. GOOD BOATING CONDITIONS ARE EXPECTED THROUGH SAT WITH LIGHT S/SW WINDS. WAVEWATCH AND LOCAL SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TONIGHT THROUGH SATURDAY. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/ AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND. THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DAG |
| #531588 (Received by flhurricane at: 5:48 PM 03.Aug.2012) AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 440 PM CDT FRI AUG 3 2012 .DISCUSSION... LATEST WATER VAPOR SATELLITE IMAGERY/UPPER AIR ANALYSIS SHOWED UPPER RIDGE CENTERED OVER CENTRAL/EASTERN TEXAS...WITH A DISCERNIBLE SHORTWAVE EVIDENT DROPPING SOUTH THROUGH CENTRAL LOUISIANA. AT THE SFC...HIGH PRESSURE RIDGES WWD FROM THE ATLANTIC ACROSS THE NORTHERN GULF OF MEXICO. LATEST RADAR IMAGERY SHOWERS ISOLATED-SCATTERED CONVECTION ONGOING ACROSS SOUTH CENTRAL/SOUTHEAST LA. HAVE KEPT THE EVENING AND OVERNIGHT FCST DRY WITH THE IDEA THAT THE LOSS OF DAYTIME HEATING SHOULD RESULT IN THIS ACTIVITY WANING...BUT WITH THE LIFT ASSOCIATED WITH THE PASSING SHORTWAVE...IT MAY CONTINUE INTO THE EVENING HOURS...AND WOULD NOT BE SURPRISED IF THE EVENING CREW HAD TO EXTEND A SMALL POP BEYOND 00Z. NO MAJOR CHANGES WERE MADE TO THE GRIDDED FORECAST THIS AFTERNOON. GLOBAL MODELS CONTINUE TO SHOW THE MID/UPPER RIDGE LIFT A BIT TO THE NORTH TOMORROW...BEFORE RETROGRADING WWD ON SUNDAY...WITH DEEPER MOISTURE WORKING ITS WAY WEST INTO THE REGION. THIS...ALONG WITH SHORTWAVE ENERGY SLIDING UNDERNEATH THE RIDGE TOMORROW...AND TRAVERSING THE REGION ON SUNDAY...WILL RESULT IN INCREASING RAIN CHANCES THROUGH THE WEEKEND. THE RIDGE IS FCST TO CONTINUE WWD AND AMPLIFY OVER THE FOUR CORNERS REGION NEXT WEEK...LEAVING THE REGION WITHIN A WEAKNESS/SHEAR AXIS BETWEEN THIS RIDGE AND THE SUBTROPICAL RIDGE TO THE EAST. OTHER THAN MONDAY AND PERHAPS INTO TUESDAY...WHEN AN INVERTED UPPER TROF IS PROGGED TO PASS TO OUR SOUTH...DID NOT SEE ANYTHING CONCRETE TO HANG MY HAT ON IN TERMS OF RAISING RAIN CHANCES ABOVE CLIMO...BUT BEING IN NW FLOW ALOFT CAN OFTEN BRING SURPRISES. REGARDING THE TROPICS...THE PROGRESS OF ERNESTO WILL OF COURSE CONTINUE TO BE MONITORED. THE LATEST OFFICIAL TRACK FROM NHC BRINGS ERNESTO TO THE YUCATAN PENINSULA AS A HURRICANE BY WEDNESDAY AFTERNOON...WITH A COORDINATED NHC/HPC TRACK CONTINUING A GENERAL NW MOTION INTO THE SW GULF ON DAYS 6 AND 7. THERE REMAINS A LARGE MODEL SPREAD IN THIS LATTER PART OF THE FORECAST...THUS RESIDENTS ARE ENCOURAGED TO KEEP UP WITH THE LATEST NHC FORECASTS. 13 && .MARINE... SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE ACROSS THE NORTHERN GULF OF MEXICO FROM THE WESTERN ATLANTIC. THIS WILL RESULT IN MAINLY ONSHORE FLOW AND RELATIVELY LOW SEAS THROUGH THE WEEKEND...HEADING INTO NEXT WEEK. 13 && .PRELIMINARY POINT TEMPS/POPS... KLCH 77 93 76 93 / 10 20 10 60 KBPT 76 92 77 92 / 10 20 10 60 KAEX 77 96 76 94 / 10 20 10 50 KLFT 77 92 76 91 / 10 20 20 60 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ |
| #531582 (Received by flhurricane at: 5:17 PM 03.Aug.2012) AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 407 PM CDT FRI AUG 3 2012 .SYNOPSIS... LATEST SURFACE ANALYSIS SHOWED A BROAD 1016MB HIGH OVER NORTHEAST GULF AND AN INVERTED TROUGH OVER THE BAHAMAS. UPPER LEVEL CHARTS AND SATELLITE REVEALED A HIGH OVER TEXAS AND ANOTHER HIGH OVER EASTERN ATLANTIC NEAR 70W...CREATING A SOMEWHAT COL FROM MISSISSIPPI TO FLORIDA. SOUNDING SHOWED INCREASE IN PW VALUE UP 2.15 INCHES FOR THIS MORNING...LIGHT SOUTHWEST FLOW 1000MB TO 800MB AND NORTHEAST TO NORTH FLOW 650MB TO 400MB. VAD WIND PROFILE CONTINUE TO SHOW THIS WIND PROFILE WITH STEERING WINDS PUSHING CONVECTION SLOWLY WESTWARD. WITH A FEW AREAS RECEIVING BRIEF DOWNPOURS...RELIEF HAS BEEN LIMITED WITH DEWPOINT READINGS CLIMBING UP TO NEAR 80 AT A FEW POINTS...ASD HOVERED AROUND 80 DEGREE DEWPOINT AFTER BRIEF SHOWER. ERGO...WILL LET HEAT ADV EXPIRE AT 7 PM THIS EVENING. && .DISCUSSION... UPPER LEVEL HIGH OVER TEXAS SHOULD REMAIN STATIONARY THROUGH SATURDAY. PRECIPITABLE WATER VALUE SHOULD REMAIN SLIGHTLY ABOVE 2 INCHES FOR TONIGHT AND SATURDAY. LOOKING FOR TEMPS TO DROP POSSIBLE 1 OF 2 DEGREES TONIGHT LOWER THAN THIS MORNING WITH DEWPOINT READINGS IN THE MID 70S. IN ADDITION...TEMPS AND HEAT INDEX VALUE WILL APPROACH 100F BY 11 AM SATURDAY. HOWEVER...SCATTERED CLOUDS THEN CONVECTION WILL DISTURB DANGEROUS HEAT INDEX VALUES THROUGHOUT THE DAY. WILL ALLOW HEAT ADVISORY TO EXPIRE THIS EVENING WITH THE INCREASE RAIN CHANCES. THE SURFACE FEATURE ASSOCIATED WITH AREA OF DISTURBED WEATHER OVER BAHAMAS WILL MOVE ACROSS FLORIDA OVER THE WEEKEND AND APPROACH NORTH CENTRAL GULF BY MONDAY. UPPER LEVEL WINDS ARE EXPECTED TO WEAKEN OVER FLORIDA BUT THE PENINSULA WILL HAMPER DEVELOPMENT THROUGH THE WEEKEND AND NEXT WEEK. WILL INCREASE RAIN CHANCES FOR MONDAY WITH SURFACE FEATURE REMAINING AN INVERTED TROUGH NEXT MONDAY FOR NOW. GFS...ECMWF AND NHC KEEP EARNESTO WELL SOUTH 22N THROUGH NEXT 5 DAYS AND HPC KEEPS EARNEST SOUTH OF 23N THROUGH NEXT 7 DAYS. FOR NOW...UPPER LEVEL HIGH WILL SLOWLY RETREAT OVER ROCKIES AND CENTRAL PLAINS TUESDAY THROUGH FRIDAY. THIS WILL ALLOW UPPER FLOW TO PUSH SOUTH TO APPROACH THE FORECAST AREA THURSDAY INTO FRIDAY. MOISTURE AXIS MAY POOL OVER THE AREA...THIS WILL MAINTAIN RAIN CHANCES AROUND 30 PERCENT DAY 5 THROUGH DAY 7 && .AVIATION... VFR CONDITIONS WILL PREVAIL OUTSIDE OF ANY CONVECTION THROUGH THE REMAINDER OF THE AFTN AND EVNG HRS. BEST CHANCE FOR CONVECTION WILL BE ALONG THE ERN HALF OF THE CWA MAINLY TERMINALS EAST OF THE I-55 CORRIDOR. ONCE SHRA/TSRA DISSIPATE LOOK FOR VFR CONDITIONS THROUGH THE NIGHT. ONLY ISSUE COULD BE THE TYPICAL PROBLEM SITES THAT SEE MVFR VISBIES DURING THE EARLY MORNING HRS. /CAB/ && .MARINE... A BROAD RIDGE OF HIGH PRESSURE ACROSS THE NORTH GULF WILL PERSIST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. AN AREA OF DISTURBED WEATHER WILL TRACK ACROSS FLORIDA OVER THE WEEKEND AND MOVE ACROSS THE NORTH CENTRAL GULF OF MEXICO. THIS FEATURE WILL INCREASE RAIN CHANCES OVER THE COASTAL WATERS MONDAY THROUGH THURSDAY. GENERALLY LIGHT AND SOMEWHAT VARIABLE FLOW ACROSS THE COASTAL WATERS THROUGH SUNDAY. A NORTH WINDS MAY OCCUR AS THE WAVE APPROACHES THE COASTAL WATERS MONDAY. WINDS WILL RETURN TO LIGHT SOUTHERLY TUESDAY AND WEDNESDAY WITH MAINLY BE 10 KNOTS OR LESS AND SEAS 2 FEET OR LESS. 18 && .PRELIMINARY POINT TEMPS/POPS... MCB 74 93 74 94 / 10 40 20 40 BTR 76 95 76 94 / 10 30 20 40 ASD 75 93 76 92 / 10 40 20 40 MSY 79 92 80 93 / 10 40 20 40 GPT 76 93 76 94 / 20 40 20 40 PQL 74 93 74 94 / 20 40 20 40 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...HEAT ADVISORY UNTIL 7 PM FRIDAY FOR THE FOLLOWING ZONES: ASCENSION...ASSUMPTION...EAST BATON ROUGE...EAST FELICIANA...IBERVILLE...LIVINGSTON...LOWER JEFFERSON...LOWER LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER TERREBONNE...NORTHERN TANGIPAHOA...ORLEANS...POINTE COUPEE...SOUTHERN TANGIPAHOA...ST. CHARLES...ST. HELENA...ST. JAMES...ST. JOHN THE BAPTIST...ST. TAMMANY...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER PLAQUEMINES...UPPER ST. BERNARD...UPPER TERREBONNE...WASHINGTON...WEST BATON ROUGE...AND WEST FELICIANA. GM...NONE. MS...HEAT ADVISORY UNTIL 7 PM FRIDAY FOR THE FOLLOWING ZONES: HANCOCK...HARRISON...JACKSON...AND PEARL RIVER. GM...NONE. && $$ |
| #531581 (Received by flhurricane at: 5:09 PM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 506 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE SOUTHEAST COAST WILL ALLOW FOR WARM AND HUMID CONDITIONS ACROSS THE AREA THROUGH THE WEEKEND. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL ALSO CONTINUE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH THE REGION ON MONDAY RESULTING IN BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... LATEST SATELLITE TRENDS SHOW EXPANDING CU FIELD ACROSS NC/VA AS MOST ORGANIZED ACTIVITY REMAINS CLOSE TO MID LEVEL SHORTWAVE IN KY/TN AND UPPER LEVEL LOW IN SE NC. FEW TOWERS ATTEMPTED TO GO UP JUST SOUTH OF RICHMOND...BUT WARMING ALOFT HAS REALLY LIMITED UPDRAFT STRENGTH THUS FAR. 700MB THETA E RIDGE SET UP ACROSS SE VA/NE NC WITH OBSERVED DEWPOINTS INCREASING INTO THE LOW 70S. LATEST BLENDED PRECIP WATERS HAVE INCREASED TO 1.5 TO 1.6 INCHES. WITH THAT SAID...SUFFICIENT LOW LEVEL MOISTURE EXIST FOR AFTERNOON CONVECTION. THE LIMITING FACTORS SO FAR TODAY HAVE BEEN WARMING ALOFT (REDUCING MID LEVEL LAPSE RATES) WITH 500MB TEMPS PROGGED AROUND 6-7C...AND DRY MID TO UPPER LEVELS...500MB RH AT 20 PCT. MIXED LAYER CAPE INCREASES OF AROUND 1000 J/KG OVER THE PAST 3 HOURS TO AROUND 2000 J/KG SHOULD INITIATE DECENT UPDRAFTS ACROSS THE AREA. LATEST MODEL SOLUTIONS HAVE STRUGGLED HANDLING AFTERNOON CONVECTION SO HAVE OPTED TO LEAVE CURRENT SCATTERED POPS FOR THIS AFTERNOON ALONE. DUE TO WEAK FLOW/SHEAR...LOCALLY HEAVY RAINFALL WILL AGAIN BE POSSIBLE. STORM MERGERS AND STEEP LOW LEVEL LAPSE RATES WILL ALSO PROVIDE THE POSSIBILITY OF LOCALIZED STRONG GUSTY WINDS. LOSS OF DAYTIME HEATING WILL ALLOW FOR A RAPID DECREASE IN COVERAGE THIS EVENING. AFTERNOON TEMPERATURES HAVE REACHED INTO THE UPPER 80S NEAR THE COASTS TO LOW 90S ELSEWHERE. LOCAL HEAT INDICES IN MID/UPPER 90S WITH A FEW LOCALIZED 100 DEG READINGS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... SHORTWAVE TROUGH TO LIFT NE SATURDAY WITH BERMUDA HI PRESSURE EXPANDING WESTWARD. SWLY FLOW ALOFT WILL ALLOW FOR CONTINUED HUMID CONDITIONS WITH ABOVE NORMAL DAYTIME TEMPERATURES. A STRONG MID LEVEL SHORTWAVE WILL APPROACH THE GREAT LAKES REGION THROUGH THE WEEKEND. WEAK MID LEVEL DISTURBANCES WILL COMBINE WITH THE WARM AND HUMID AIRMASS TO PROVIDE ISOLATED/SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. TEMPERATURES THIS WEEKEND WILL RANGE FROM THE UPPER 80S TO LOW/MID 90S UNDER MOSTLY SUNNY TO PARTLY CLOUDY SKIES. HEAT INDICES EXPECTED TO REMAIN BELOW HEAT ADVISORY CRITERIA. A COLD FRONT IS PROGGED TO REACH CENTRAL VA BY MONDAY MORNING/AFTERNOON RESULTING IN MORE ORGANIZED AND WIDESPREAD CONVECTION MONDAY AFTERNOON. ATTM...GFS/ECMWF SOLUTIONS TEND TO BE MORE PROGRESSIVE/DEEPER WITH SFC TROUGH MONDAY THAN NAM/SREF SOLUTIONS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... WE HAVE ARRIVED AT THE TIME OF YEAR WHERE FRONTS HAVE A TUFF TIME MOVING SOUTH OF THE REGION DUE TO THE STRENGTH OF THE BERMUDA HIGH. NEXT WEEK WILL FEATURE ONE SUCH BOUNDARY THAT STALLS AND WEAKENS ACROSS THE REGION BY TUESDAY...LINGERS AS A LEE TROF WEDNESDAY AND THURSDAY WITH ANOTHER FRONTAL BOUNDARY APPROACHING FROM THE NORTH FRIDAY. RESULT WILL BE A TRIGGER FOR CHC POPS EACH DAY...CONCENTRATING ON THE AFTERNOON/EVENING HOURS. BEST MOISTURE AND HIGHEST POPS SEEN MONDAY NIGHT THROUGH WEDNESDAY. SLGHT CHC POPS THURSDAY EXCEPT CHC ACROSS THE SE. SLGHT CHC FRI FOR NOW. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 8-10KT TODAY. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED THROUGH THE AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE. VERY ISOLATED FOG IS POSSIBLE DUE TO RESIDUAL MOISTURE FROM SHOWERS AND TSTMS. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... NO FLAGS AS SRLY FLOW ARND BERMUDA HIGH PRESSURE DOMINATES THROUGH THE WEEKEND. SOME CHANELLING UP THE BAY TONIGHT AND SAT NIGHT WILL KEEP WINDS BTWN 10-15 KTS. INCRG PRESSURE GRADIENT AHEAD OF APPRCHG BOUNDARY/TROF MAY RESULT IN MINIMAL SCA CONDITIONS SUN NIGHT / MON. BOUNDARY STALLS/WEAKENS OVER THE REGION EARLY NEXT WEEK WITH SW FLOW CONTINUING. && .EQUIPMENT... KDOX RADAR HAS RETURNED TO NORMAL OPERATIONS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...SAM |
| #531578 (Received by flhurricane at: 4:56 PM 03.Aug.2012) AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 350 PM CDT FRI AUG 3 2012 .DISCUSSION... DRY AND WARM WEATHER CONTINUES AS THE UPPER LEVEL RIDGE REMAINS CENTERED ACROSS THE STATE. MODELS IN GOOD AGREEMENT IN SHIFTING THE RIDGE BACK TO THE WEST OVER THE WEEKEND AND ALLOWING INCREASED MOISTURE TO FLOW INTO THE REGION. RAIN CHANCES WILL BE ON THE INCREASE THROUGH THE BEGINNING OF NEXT WEEK AS LOWER HEIGHTS AND PW VALUES OF AROUND 2.O INCHES WILL ALLOW FOR GREATER DEVELOPMENT ALONG THE SEABREEZE DURING THE AFTERNOON HOURS. MONDAY STILL LOOKS TO HOLD THE GREATEST CHANCE FOR RAIN AND WILL KEEP CURRENT CHANCE POPS IN PLACE. THE RIDGE LOOKS TO REMAIN WELL TO THE WEST THROUGH MUCH OF THE WEEK...ALTHOUGH IT WILL BEGIN TO REDEVELOP SLIGHTLY FURTHER NORTH BEFORE DRIFTING BACK TO THE EAST. THIS SHOULD ALLOW FOR TYPICAL SUMMERTIME CONDITIONS WITH AFTERNOON SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE COASTAL COUNTIES AND THEN MOVING INLAND WITH THE SEABREEZE. TEMPERATURES WILL BE SLIGHTLY COOLER THAN THIS WEEK BUT STILL EXPECTING MOST AREAS TO REACH THE LOW TO MID 90S EACH AFTERNOON NEXT WEEK. WE CONTINUE TO KEEP AN EYE ON TS ERNESTO WHICH IS LOOKING SOMEWHAT DISORGANIZED AS IT CONTINUES ON ITS CURRENT WEST NORTHWESTWARD TRACK. THE OFFICIAL NHC FORECAST TRACK TAKES IT ASHORE ALONG THE YUCATAN PENINSULA AROUND THE MIDDLE OF NEXT WEEK. 38 && .MARINE... ANOTHER DAY AND HALF OF WINDS 10-15 KNOTS BEFORE UPPER RIDGING RETREATS AND WINDS BECOME MORE SOUTH TO SOUTHEAST AND DRIVEN BY LAX GRADIENT/DIURNAL HEATING. SEAS SHOULD LOWER UNTIL WINDS BEGIN TO INCREASE AGAIN TOWARD THE MIDDLE OF THE WEEK. STILL TO FAR OUT FOR MUCH CONFIDENCE ON ERNESTO HAVING MUCH IF ANY IMPACT TO THE MARINE WATERS. A LITTLE MORE CONCERNED ABOUT THE SYSTEM EAST OF FLORIDA MOVING TOWARD NEW AND BRINGING ABUNDANT MOISTURE TO THE UPPER TEXAS COASTAL WATERS AND INCREASED COVERAGE OF SHOWERS AND THUNDERSTORMS. 45 && .AVIATION... STRONG HEATING ACROSS N TX/OK HELPING TO PULL WINDS AROUND TO THE SOUTH THIS AFTERNOON. EXPECT THAT CU SHOULD DISSIPATE BY 01-02Z. STILL FAIRLY CONFIDENT OF PATCHY MVFR CIGS AFTER SUNRISE FOR A FEW HOURS THEN LIGHTER MORE SOUTHERLY WINDS THAN TODAY. 45 .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 76 98 76 98 76 / 0 10 10 20 10 HOUSTON (IAH) 78 94 78 94 75 / 0 20 10 30 10 GALVESTON (GLS) 82 91 82 91 80 / 0 20 20 30 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531574 (Received by flhurricane at: 4:48 PM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE NEW YORK NY 443 PM EDT FRI AUG 3 2012 .SYNOPSIS... LARGE HIGH PRESSURE OFF THE ATLANTIC COAST WILL REMAIN STATIONARY THROUGH SATURDAY. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY... THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... WARM TEMPS AND HIGH DEW POINTS HAVE RESULTED IN HOT CONDITIONS ACROSS THE AREA...WITH PLENTY OF LOW LEVEL INSTABILITY IN PLACE. WARMING HEIGHTS ALOFT AND LACK OF TRIGGER THOUGH HAVE KEPT CONVECTION LIMITED IN COVERAGE. MAIN ACTIVITY EARLIER WAS ALONG SEA BREEZE BOUNDARY...AND WERE PULSE VARIETY WITH WEAK WINDS ALOFT. ANY CONVECTION WILL WIND DOWN THIS EVENING AS BOUNDARY LAYER COOLS AND SFC BASED INSTABILITY DECREASES. THE CWA HAS BEEN IN THIS WARM/MUGGY AIRMASS...AND TEMPS WILL DROP SLOWLY TONIGHT...WITH MANY LOCATIONS REMAINING IN THE 70S PER MOS. MID TO UPPER 60S ACROSS THE INTERIOR. DO EXPECT PATCHY FOG AS LIGHT SOUTHERLY WINDS PERSIST AND TEMP/DEW POINT DEPRESSIONS SHRINK. THERE IS MODERATE RISK OF RIP CURRENTS INTO THIS EVENING AT THE OCEAN BEACHES. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... LARGE RIDGE OVER THE WESTERN ATLANTIC AND UP THE EASTERN SEABOARD PREVAILS THIS TIME FRAME. WITH THIS RIDGE IN PLACE...LIGHT WINDS AND PLENTY OF WARM AIR ALOFT SHOULD KEEP ANY AFTERNOON/EVENING CONVECTION TO A MINIMUM. SLIGHTLY COOLER BOUNDARY LAYER WILL RESULT IN LOWER SFC/MIXED LAYER INSTABILITY AS WELL. HOWEVER...ANY SHOWER OR THUNDERSTORM THAT DOES DEVELOP WILL PULSE BRIEFLY...AND COULD BE STRONG. THE COOLER BOUNDARY LAYER IS COURTESY OF INCREASING SOUTH TO SOUTHEAST FLOW...INJECTING MARINE LAYER OVER A GOOD PORTION OF THE CWA. HOWEVER TEMPS WILL STILL BE QUITE WARM TO HOT...80S TO NEAR 90. WITH HIGH DEW POINTS REMAINING IN THE 70S...HEAT INDICES WILL ONCE AGAIN RISE INTO THE 90S. A FEW LOCATIONS IN AND AROUND NYC COULD SEE 95 DEGREE HEAT INDICES...BUT GIVEN UNCERTAINTY AND MARGINAL CONDITIONS...WILL HOLD OFF ON ANY HEAT ADVISORIES AT THIS TIME. TIME OF YEAR A FACTOR WITH SEVERAL HEAT EVENTS UNDER OUR BELT AS WELL. THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN FACING BEACHES ON SATURDAY. ON SATURDAY NIGHT...MUGGY AND WARM CONDITIONS CONTINUE WITH SOUTH FLOW PERSISTING. STRATUS AND FOG EXPECTED ONCE AGAIN. FOLLOWED A MOS BLEND CLOSELY THROUGH THIS TIME PERIOD. HARD TO BEAT MOS NUMBERS IN THIS TYPE OF STAGNANT/PERSISTENT PATTERN. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HOT AND HUMID AIRMASS IN PLACE SUNDAY AS STRONG SOUTHERLY WINDS DEVELOP DUE TO A TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRES ANCHORED OVER THE WESTERN ATLANTIC AND AN APPROACHING COLD FRONT MOVING THROUGH THE OHIO VALLEY. CONDITIONS BECOME QUITE UNSTABLE AS TEMPS CLIMB THROUGH THE 80S...AROUND 90 IN/AROUND NYC...ALONG WITH SFC DEW POINTS WELL INTO THE 70S. THIS WILL RESULT IN A HEAT INDEX CLOSE TO 100 DEGREES IN/AROUND NYC AND THE URBANIZED AREAS OF NE NJ...AND IN THE LOW TO MID 90S ELSEWHERE. STRONG SOUTHERLY FLOW...COMBINED WITH INCREASING SURF HEIGHTS... WILL LIKELY RESULT IN A HIGH RISK FOR RIP CURRENTS AT THE OCEAN BEACHES ON SUNDAY. THERE MAY BE A FEW SHOWERS/TSTMS LINGERING INTO SUNDAY MORNING AS WEAK TROUGH/SHORTWAVE MOVE THROUGH THE REGION...BUT MORE ORGANIZED ACTIVITY WILL HOLD OFF UNTIL THE AFTERNOON AND EVENING HOURS AS THE COLD FRONT OVER THE OH VALLEY MOVES INTO WESTERN NY/PA DURING THE DAY SUNDAY. PRE-FRONTAL TROUGH AHEAD OF THE COLD FRONT WILL TRACK INTO WESTERN PORTIONS OF THE FORECAST AREA BY AFTERNOON...AND THAT LOOKS TO BE A TRIGGERING MECHANISM FOR SOME RATHER STRONG TO SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING. CAPE VALUES WILL BE OVER 2000 J/KG IN SOME PARTS OF NJ AND INTO NYC...ALONG WITH A LIFTED INDEX CLOSE TO -7 C AND INCREASING LOW LEVEL WINDS. AS THIS COMPLEX COLD FRONT/UPPER TROUGH/SHORTWAVE SYSTEM MOVES INTO THE AREA SUNDAY EVENING...SHOWERS AND THUNDERSTORMS WILL INCREASE IN INTENSITY AND COVERAGE SUNDAY EVENING. THUNDERSTORMS WILL BE CAPABLE OF DAMAGING WINDS IN THE AFTERNOON...BUT WITH LOSS OF DIURNAL HEATING COMES THE LOSS OF THE THREAT FOR DAMAGING WINDS. IN ADDITION TO THE DAMAGING WIND THREAT...THERE IS ALSO THE THREAT FOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING IN THE AFTERNOON/EVENING...THEN TORRENTIAL RAINFALL SUNDAY NIGHT WILL RESULT IN THE POTENTIAL FOR FLASH FLOODING OVERNIGHT SUNDAY NIGHT INTO MONDAY MORNING. WITH PWATS RANGING FROM 2.25-2.5 INCHES...THERE IS ABUNDANT MOISTURE IN THE ATMOSPHERE TO FEED ANY THUNDERSTORMS...AND TORRENTIAL RAINFALL IS EXPECTED. THINK THE MID LEVEL WINDS WILL BE TOO STRONG TO ALLOW ANY STORM TO LINGER OVER ANY ONE AREA...BUT TRAINING OF CELLS WILL LEAD TO FLASH FLOODING. PRECIPITATION TAPERS OFF FROM WEST TO EAST MONDAY MORNING AS THE FRONTAL SYSTEM TRACKS THROUGH THE REGION. THE FRONT BECOMES STATIONARY SOUTH OF LONG ISLAND LATE MONDAY THROUGH TUESDAY AS HIGH PRES BUILDS THROUGH THE REGION ON TUESDAY. HUMIDITY LEVELS WILL FALL DRASTICALLY AS DEW POINTS DROP FROM THE 70S INTO THE LOWER 60S. TUESDAY WILL END UP QUITE PLEASANT WITH LOW HUMIDITY...FAIR SKIES AND TEMPS IN THE 80S. STATIONARY FRONT SOUTH OF LONG ISLAND LIFTS BACK NORTH AS A WARM FRONT ON WEDNESDAY. ISOLATED SHOWERS/TSTMS POSSIBLE WITH ITS PASSAGE. SFC COLD FRONT WITH UPPER LEVEL SUPPORT FROM AN H5 TROUGH/SHORTWAVE COMBO THEN APPROACHES ON THURSDAY...POSSIBLY TOUCHING OFF SOME MORE SHOWERS/TSTMS. SOME CONCERNS WITH FORECAST LATE IN THE WEEK...AS HIGH PRES MOVES THROUGH THE REGION...BUT DEPENDING ON HOW FAST IT DEPARTS WILL IMPACT IF LOW PRES UPSTREAM MAKES IT TO THE LOCAL AREA OR NOT. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... A WEAK PRESSURE PATTERN REMAINS IN PLACE THROUGH THE TAF PERIOD. GENERALLY MODERATE TO HIGH CONFIDENCE IN WIND FORECAST. SEA BREEZE NOW THROUGH ALL TERMINALS EXCEPT KSWF...AND SHOULD REMAIN SE OF KSWF. CONVECTIVE DEBRIS CIRRUS THIS AFTERNOON INTO EARLY EVENING SHOULD INHIBIT TSTM POTENTIAL AS THEY TRY TO DRIFT NORTH FROM CENTRAL NJ. NOT ENOUGH CONFIDENCE FOR SUFFICIENT COVERAGE TO INCLUDE TSTMS IN TAFS. VFR INTO THIS EVENING EXCEPT AT KGON. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. KLGA FCSTER COMMENTS: OCCASIONAL GUSTS OF 15-18 KT THROUGH 00Z. KEWR FCSTER COMMENTS: HAZE ALOFT OBSERVED. NO UNSCHEDULED AMENDMENTS ANTICIPATED. KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. OUTLOOK FOR 18Z SAT THROUGH WED... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS....MAINLY IN THE AFTERNOON. LATE DAY TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE/WED...VFR. && .MARINE... PERSISTENT SOUTHERLY FLOW CONTINUES TONIGHT THROUGH SATURDAY. SUB SCA CONDITIONS ARE ANTICIPATED. FOLLOWED WAVE WATCH III OCEAN FORECASTS CLOSELY. SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKE UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING THROUGH SATURDAY. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH THE THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MPS/PW |
| #531575 (Received by flhurricane at: 4:48 PM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 440 PM EDT FRI AUG 3 2012 .SYNOPSIS... LARGE HIGH PRESSURE OFF THE ATLANTIC COAST WILL REMAIN STATIONARY THROUGH SATURDAY. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY... THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... WARM TEMPS AND HIGH DEW POINTS HAVE RESULTED IN HOT CONDITIONS ACROSS THE AREA...WITH PLENTY OF LOW LEVEL INSTABILITY IN PLACE. WARMING HEIGHTS ALOFT AND LACK OF TRIGGER THOUGH HAVE KEPT CONVECTION LIMITED IN COVERAGE. MAIN ACTIVITY EARLIER WAS ALONG SEA BREEZE BOUNDARY...AND WERE PULSE VARIETY WITH WEAK WINDS ALOFT. ANY CONVECTION WILL WIND DOWN THIS EVENING AS BOUNDARY LAYER COOLS AND SFC BASED INSTABILITY DECREASES. THE CWA HAS BEEN IN THIS WARM/MUGGY AIRMASS...AND TEMPS WILL DROP SLOWLY TONIGHT...WITH MANY LOCATIONS REMAINING IN THE 70S PER MOS. MID TO UPPER 60S ACROSS THE INTERIOR. DO EXPECT PATCHY FOG AS LIGHT SOUTHERLY WINDS PERSIST AND TEMP/DEW POINT DEPRESSIONS SHRINK. THERE IS MODERATE RISK OF RIP CURRENTS INTO THIS EVENING AT THE OCEAN BEACHES. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... LARGE RIDGE OVER THE WESTERN ATLANTIC AND UP THE EASTERN SEABOARD PREVAILS THIS TIME FRAME. WITH THIS RIDGE IN PLACE...LIGHT WINDS AND PLENTY OF WARM AIR ALOFT SHOULD KEEP ANY AFTERNOON/EVENING CONVECTION TO A MINIMUM. SLIGHTLY COOLER BOUNDARY LAYER WILL RESULT IN LOWER SFC/MIXED LAYER INSTABILITY AS WELL. HOWEVER...ANY SHOWER OR THUNDERSTORM THAT DOES DEVELOP WILL PULSE BRIEFLY...AND COULD BE STRONG. THE COOLER BOUNDARY LAYER IS COURTESY OF INCREASING SOUTH TO SOUTHEAST FLOW...INJECTING MARINE LAYER OVER A GOOD PORTION OF THE CWA. HOWEVER TEMPS WILL STILL BE QUITE WARM TO HOT...80S TO NEAR 90. WITH HIGH DEW POINTS REMAINING IN THE 70S...HEAT INDICES WILL ONCE AGAIN RISE INTO THE 90S. A FEW LOCATIONS IN AND AROUND NYC COULD SEE 95 DEGREE HEAT INDICES...BUT GIVEN UNCERTAINTY AND MARGINAL CONDITIONS...WILL HOLD OFF ON ANY HEAT ADVISORIES AT THIS TIME. TIME OF YEAR A FACTOR WITH SEVERAL HEAT EVENTS UNDER OUR BELT AS WELL. THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN FACING BEACHES ON SATURDAY. ON SATURDAY NIGHT...MUGGY AND WARM CONDITIONS CONTINUE WITH SOUTH FLOW PERSISTING. STRATUS AND FOG EXPECTED ONCE AGAIN. FOLLOWED A MOS BLEND CLOSELY THROUGH THIS TIME PERIOD. HARD TO BEAT MOS NUMBERS IN THIS TYPE OF STAGNANT/PERSISTENT PATTERN. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HOT AND HUMID AIRMASS IN PLACE SUNDAY AS STRONG SOUTHERLY WINDS DEVELOP DUE TO A TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRES ANCHORED OVER THE WESTERN ATLANTIC AND AN APPROACHING COLD FRONT MOVING THROUGH THE OHIO VALLEY. CONDITIONS BECOME QUITE UNSTABLE AS TEMPS CLIMB THROUGH THE 80S...AROUND 90 IN/AROUND NYC...ALONG WITH SFC DEW POINTS WELL INTO THE 70S. THIS WILL RESULT IN A HEAT INDEX CLOSE TO 100 DEGREES IN/AROUND NYC AND THE URBANIZED AREAS OF NE NJ...AND IN THE LOW TO MID 90S ELSEWHERE. STRONG SOUTHERLY FLOW...COMBINED WITH INCREASING SURF HEIGHTS... WILL LIKELY RESULT IN A HIGH RISK FOR RIP CURRENTS AT THE OCEAN BEACHES ON SUNDAY. THERE MAY BE A FEW SHOWERS/TSTMS LINGERING INTO SUNDAY MORNING AS WEAK TROUGH/SHORTWAVE MOVE THROUGH THE REGION...BUT MORE ORGANIZED ACTIVITY WILL HOLD OFF UNTIL THE AFTERNOON AND EVENING HOURS AS THE COLD FRONT OVER THE OH VALLEY MOVES INTO WESTERN NY/PA DURING THE DAY SUNDAY. PRE-FRONTAL TROUGH AHEAD OF THE COLD FRONT WILL TRACK INTO WESTERN PORTIONS OF THE FORECAST AREA BY AFTERNOON...AND THAT LOOKS TO BE A TRIGGERING MECHANISM FOR SOME RATHER STRONG TO SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING. CAPE VALUES WILL BE OVER 2000 J/KG IN SOME PARTS OF NJ AND INTO NYC...ALONG WITH A LIFTED INDEX CLOSE TO -7 C AND INCREASING LOW LEVEL WINDS. AS THIS COMPLEX COLD FRONT/UPPER TROUGH/SHORTWAVE SYSTEM MOVES INTO THE AREA SUNDAY EVENING...SHOWERS AND THUNDERSTORMS WILL INCREASE IN INTENSITY AND COVERAGE SUNDAY EVENING. THUNDERSTORMS WILL BE CAPABLE OF DAMAGING WINDS IN THE AFTERNOON...BUT WITH LOSS OF DIURNAL HEATING COMES THE LOSS OF THE THREAT FOR DAMAGING WINDS. IN ADDITION TO THE DAMAGING WIND THREAT...THERE IS ALSO THE THREAT FOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING IN THE AFTERNOON/EVENING...THEN TORRENTIAL RAINFALL SUNDAY NIGHT WILL RESULT IN THE POTENTIAL FOR FLASH FLOODING OVERNIGHT SUNDAY NIGHT INTO MONDAY MORNING. WITH PWATS RANGING FROM 2.25-2.5 INCHES...THERE IS ABUNDANT MOISTURE IN THE ATMOSPHERE TO FEED ANY THUNDERSTORMS...AND TORRENTIAL RAINFALL IS EXPECTED. THINK THE MID LEVEL WINDS WILL BE TOO STRONG TO ALLOW ANY STORM TO LINGER OVER ANY ONE AREA...BUT TRAINING OF CELLS WILL LEAD TO FLASH FLOODING. PRECIPITATION TAPERS OFF FROM WEST TO EAST MONDAY MORNING AS THE FRONTAL SYSTEM TRACKS THROUGH THE REGION. THE FRONT BECOMES STATIONARY SOUTH OF LONG ISLAND LATE MONDAY THROUGH TUESDAY AS HIGH PRES BUILDS THROUGH THE REGION ON TUESDAY. HUMIDITY LEVELS WILL FALL DRASTICALLY AS DEW POINTS DROP FROM THE 70S INTO THE LOWER 60S. TUESDAY WILL END UP QUITE PLEASANT WITH LOW HUMIDITY...FAIR SKIES AND TEMPS IN THE 80S. STATIONARY FRONT SOUTH OF LONG ISLAND LIFTS BACK NORTH AS A WARM FRONT ON WEDNESDAY. ISOLATED SHOWERS/TSTMS POSSIBLE WITH ITS PASSAGE. SFC COLD FRONT WITH UPPER LEVEL SUPPORT FROM AN H5 TROUGH/SHORTWAVE COMBO THEN APPROACHES ON THURSDAY...POSSIBLY TOUCHING OFF SOME MORE SHOWERS/TSTMS. SOME CONCERNS WITH FORECAST LATE IN THE WEEK...AS HIGH PRES MOVES THROUGH THE REGION...BUT DEPENDING ON HOW FAST IT DEPARTS WILL IMPACT IF LOW PRES UPSTREAM MAKES IT TO THE LOCAL AREA OR NOT. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... A WEAK PRESSURE PATTERN REMAINS IN PLACE THROUGH THE TAF PERIOD. GENERALLY MODERATE TO HIGH CONFIDENCE IN WIND FORECAST. SEA BREEZE NOW THROUGH ALL TERMINALS EXCEPT KSWF...AND SHOULD REMAIN SE OF KSWF. CONVECTIVE DEBRIS CIRRUS THIS AFTERNOON INTO EARLY EVENING SHOULD INHIBIT TSTM POTENTIAL AS THEY TRY TO DRIFT NORTH FROM CENTRAL NJ. NOT ENOUGH CONFIDENCE FOR SUFFICIENT COVERAGE TO INCLUDE TSTMS IN TAFS. VFR INTO THIS EVENING EXCEPT AT KGON. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. KLGA FCSTER COMMENTS: OCCASIONAL GUSTS OF 15-18 KT THROUGH 00Z. KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS ANTICIPATED. OUTLOOK FOR 18Z SAT THROUGH WED... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS....MAINLY IN THE AFTERNOON. LATE DAY TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE/WED...VFR. && .MARINE... PERSISTENT SOUTHERLY FLOW CONTINUES TONIGHT THROUGH SATURDAY. SUB SCA CONDITIONS ARE ANTICIPATED. FOLLOWED WAVE WATCH III OCEAN FORECASTS CLOSELY. SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKE UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING THROUGH SATURDAY. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH THE THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MPS/PW |
| #531569 (Received by flhurricane at: 4:36 PM 03.Aug.2012) AFDMOB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 331 PM CDT FRI AUG 3 2012 .SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...CHART FEATURES SHOW A STATIONARY FRONT IS ANALYZED MEANDERING THROUGH THE SOUTHEAST STATES, SUPPORTED BY AN UPPER TROUGH WITH A STRONG VORTLOBE FORECAST TO PASS INTO THE CWA AROUND SUNSET. BELIEVE EXTENSION OF SEVERE THUNDERSTORM WATCH IS UNLIKELY DUE TO LOSS OF HEATING WHEN THAT FEATURE ARRIVES. WATER VAPOR IMAGERY INDICATES THE GFS INITIALIZED WELL ON THE POSITION OF SAID FEATURE... WATER VAPOR IMAGERY INDICATES ANTICYCLONIC TURNING IN THE 700 TO 300 MB LAYER AND THE IR SHOWS COOLING TOPS FROM A NUMBER OF MCS`S IN THE REGION DOWN TO -72 C WELL NORTH AND -60 TO -65 IN SMALLER FEATURES OVER NORTH ESCAMBIA AND NORTH CENTRAL BALDWIN COUNTIES AS OF MID AFTERNOON. RADAR DATA INDICATE THESE HAVE STRONG UPDRAFTS IN WHICH 50 DBZ CORES ARE TOUCHING OR GOING A BIT PAST -20C. WIND GUSTS ABOVE 60 MPH ARE POSSIBLE UNTIL AROUND SUNSET. WE BELIEVE SATURDAY WILL SHOW A LESSER RISK OF MICROBURSTS THAN TODAY DESPITE HIGHER POPS CALCULATED. AS FOR MODEL OUTPUTS, PRECIPITABLE WATER IN NAM AND GFS AROUND 2 TO 2.2 INCHES. INSTABILITY A LITTLE MORE SUBDUED THAN TODAY...ABOUT 2000 TO 2400 FOR THE CAPE AND -4 FOR LI. MID LEVEL VORTLOBES MOVING IN FROM THE OHIO VALLEY SOUTHWARD OVER THE REGION WILL SHOVE THE LAYER UPWARD ENOUGH TO FORCE SOME CONVECTION. GIVEN LITTLE TO NO CHANGE...THE GFS OUTPUT SEEMS PLAUSIBLE SO WE STUCK WITH IT. WRF ARW EAST SHOWS CONVECTIVE INITIATION TO BEGIN ALONG THE COAST ABOUT MIDMORNING. THE HRRR DOES NOT FORECAST OUT FAR ENOUGH SO WE CANNOT COMPARE.. IN ANY CASE A FEW OF THE THUNDERSTORMS SATURDAY CAN BRING STRONG GUSTY WINDS TO 45 MPH FREQUENT LIGHTNING...LOCALLY HEAVY RAIN AND SMALL HAIL. ONE OR TWO COULD ALSO INTENSIFY BRIEFLY TO SEVERE CRITERIA WITH WINDS OVER 60 MPH AND HAIL TO AROUND QUARTER SIZE. STORM MOTION EXPECTED TO BE A DRIFT TO THE SOUTH 5 TO 10 MPH. BEFORE THE ONSET OF STORMS...HIGHS INTO THE MID 90S OVER THE INTERIOR AND CLOSER TO 90 ALONG THE COAST. TONIGHT`S LOWS IN THE LOWER/MID 70S. FOR SUNDAY WE ARE EXPECTING TO SEE VORTLOBES ALONG THE EASTERN EDGE OF THE UPPER HIGH IN THE SOUTHERN PLAINS AND APPROACH FROM THE NORTH. IT WILL BE A DIURNAL RHYTHM OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE WEEKEND DURING THE DAY AND BECOMING ISOLATED OVERNIGHT. HIGH TEMPERATURES BOTH DAYS WILL REMAIN NEAR NORMAL...MID 90S AND WITH RH AROUND 60 PERCENT...HEAT INDICES WILL BE CLOSE TO THAT. HIGHEST AFTERNOON HEAT INDICES WILL RANGE FROM 96 TO 101 DEGREES. LOWS BOTH NIGHTS WILL BE IN THE LOWER TO MID 70S INLAND AREAS...WITH UPPER 70S ALONG THE BEACHES. ON TROPICAL STORM ERNESTO...THE OFFICIAL NHC FORECAST TRACK CONTINUES MOVING THE SYSTEM THROUGH CARIBBEAN SEA THIS WEEKEND AND INTENSIFYING INTO A HURRICANE SOUTH OF JAMAICA LATE SUNDAY. INTENSIFICATION OF ERNESTO AS FORECAST IS LARGELY ATTRIBUTED TO THE SYSTEM MOVING INTO AN AREA OF VERY LOW WIND SHEAR AND OVER SEA SURFACE TEMPERATURES IN THE LOW 80S. /77 && .LONG TERM [MONDAY THROUGH THURSDAY]...ERNESTO IS FORECAST TO CONTINUE TO TRACK ABOUT 280 TO 290 DEGREES REACHING SOUTH OF THE TIP OF THE YUCATAN PENINSULA EARLY WEDNESDAY. ELSEWHERE THE UPPER SADDLE POINT WILL REMAIN OVER THE FORECAST AREA THROUGHOUT THE LONG TERM. SEABREEZE DRIVEN CONVECTION WILL PERSIST THROUGH THE LONG TERM...IN A DIURNAL CYCLE OF SCATTERED SHOWERS AND THUNDERSTORMS EACH DAY AS VORTLOBES CONTINUE TO MOVE OVER THE FORECAST AREA. HIGHS EACH DAY FROM 90 TO 95 DEGREES. HIGHEST HEAT INDICES WILL RISE SLOWLY TO 96 TO 101 DEGREES BY NEXT WEEKEND. LOWS EACH NIGHT THROUGH THE ENTIRE LONG TERM WILL BE IN THE LOWER TO MID 70S INLAND AREAS...WITH UPPER 70S ALONG THE BEACHES. /77 && .AVIATION (03.18Z ISSUANCE)...SCATTERED TSRA WILL CONTINUE TO INCREASE AROUND THE TERMINALS THROUGH THE AFTERNOON. THE CONVECTION WILL DISSIPATE THIS EVENING FOLLOWED BY MORE DEVELOPMENT SATURDAY MORNING. /13 && .MARINE...SURFACE HIGH PRESSURE OVER THE SOUTHWEST ATLANTIC NOSES WESTWARD INTO THE GULF THROUGH THE EARLY HALF OF NEXT WEEK. THIS WILL MAINTAIN A GENERAL LIGHT ONSHORE FLOW WITH SEA HEIGHTS 2 FEET OR LESS. WINDS...WAVES AND SEAS LOCALLY HIGHER NEAR STORMS. /13 && .FIRE WEATHER...WITH A SURFACE HIGH OVER THE WESTERN ATLANTIC AND ANOTHER OVER TEXAS...LIGHT SOUTH WINDS WILL CONTINUE THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND THUNDERSTORMS EACH MORNING BECOMING MORE NUMEROUS EACH AFTERNOON. TRANSPORT WINDS TO REMAIN LIGHT...ACTUALLY WEAKER THAN SURFACE WINDS SINCE THERE IS AN UPPER TROUGH OVER THE NORTHEASTERN STATES CAUSING WIND TO REVERSE DIRECTION AT ABOUT 4000 TO 5000 FEET. MIXING HEIGHTS WILL BE JUST DEEP ENOUGH TO BRING SOME DISPERSION IN THE DAYTIME...ALBEIT IN THE 20S AND 30S. /77 && .PRELIMINARY POINT TEMPS/POPS... MOBILE 75 92 73 94 / 30 50 30 40 PENSACOLA 77 92 75 93 / 30 40 30 30 DESTIN 78 91 78 91 / 30 40 30 40 EVERGREEN 74 93 71 95 / 40 50 40 40 WAYNESBORO 74 93 72 95 / 30 60 40 40 CAMDEN 75 94 72 95 / 40 70 50 40 CRESTVIEW 71 93 70 94 / 30 40 30 40 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$ |
| #531562 (Received by flhurricane at: 4:14 PM 03.Aug.2012) AFDKEY AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS NATIONAL WEATHER SERVICE KEY WEST FL 410 PM EDT FRI AUG 3 2012 .DISCUSSION... .CURRENTLY...INFRARED AND WATER VAPOR SATELLITE IMAGERY SHOWS THAT THE TROPICAL WAVE THAT IS CURRENTLY CENTERED OVER THE BAHAMAS HAS BEEN SHARPENING FOR THE PAST 24 HOURS... WITH AN INTENSIFICATION OF THE CONVECTIVE ACTIVITY THAT EXTENDS FROM WESTERN SOUTH FLORIDA TO THE EASTERN BAHAMAS AT THIS HOUR. A SHARP MOISTURE GRADIENT EXISTS ACROSS THE CWA AS IF 15Z. AT THAT TIME...MIMIC TPW INDICATED AROUND 1.5 PWAT VALUES IN THE AREA OF THE DRY TORTUGAS... WHICH INCREASE TO NEAR 2.25 INCHES IN THE AREA OF ANDROS IN THE BAHAMAS. ALONG THE SHARPEST PORTION OF THIS MOISTURE GRADIENT...THE UPPER KEYS AND FLORIDA BAY HAVE BEEN VERY ACTIVE WITH THIS MOISTURE BOUNDARY. VAD WIND PROFILE HAS SHOWN PRETTY CONSISTENTLY THAT WINDS HAVE BEEN NORTHERLY IN THE VERTICAL SINCE MID MORNING. AND AS SUCH...THE STRONGEST WINDS HAVE BEEN ASSOCIATED WITH SHOWERS THAT HAVE A SOUTHERLY MOTION. DESPITE THE SHOWER ACTIVITY... BACKGROUND WINDS ARE STILL VARIABLE AROUND 5 TO 10 KNOTS. WINDS SHOULD CONTINUE AS VARIABLE AROUND 5 TO 10 KNOTS TONIGHT OUTSIDE OF SHOWERS AND THUNDERSTORMS. CONSIDERED RAISING POPS TONIGHT...BUT THE UPPER KEYS ARE CURRENTLY IN A WORKED OVER ATMOSPHERE...AND ANY SHOWERS OVER THE LOWER KEYS AND GULF WATERS WILL HAVE TO BE FIGHTING A FEW DRY AIR POCKETS IN THE VERTICAL THROUGH THE EVENING. ONLY CHANGE TO THE FORECAST IN THE SHORT TERM WAS TO RAISE POPS TO 40 PERCENT FOR MONDAY AS THERE IS NOT A SINGLE PERIOD THAT CAN BE PINPOINTED IN THE NEXT 5 DAYS WHERE RAIN CHANCES WILL BE BETTER THAN ANY OTHER. THIS CAN BE OWED TO AMPLE MOISTURE IN THE REGION AND THE PRESENCE OF THE TROPICAL WAVE. IN THE EXTENDED...THE NORTHERN EXTENT OF THE WIND FEILD OF ERNESTO IS STILL IN DOUBT. THE GFS TRENDED OUR WINDS OVER THE STRAITS DOWN JUST A BIT THIS MODEL CYCLE OWNING TO A SOUTHERLY TRACK OF ERNESTO...DUE TO UNCERTAINTY...HAVE BLENDED THE PREVIOUS FORECAST WITH A BIT OF THE GFS AND EURO THAT ARE COMING INTO CONSENSUS OF A NEAR 15 KNOT WIND WITH ERNESTO`S PASSAGE....WITH ONLY THE MOST SOUTHERN PORTIONS OF THE STRAITS SCENING NEAR 20 KNOT WINDS. THIS WILL BE SUBJECT TO CHANGE HOWEVER AS CONFIDENCE IN THE TRACK GROWS. OTHERWISE... NO SIGNIFICANT CHANGES. && .MARINE... MARINERS CAN EXPECT LIGHT AND VARIABLE CONDITIONS THROUGH THE EARLY WEEKEND...BUT SHOULD CERTAINLY BE PREPARED FOR STRONGER WIND GUSTS IN THE AREA OF STRONGER SHOWERS AND THUNDERSTORMS THAN WE HAVE SEEN FOR THE PAST FEW WEEK. THE INFLUENCE OF ERNESTO AND ANY ACCOMPANYING SWELL COMING FROM SOUTH OF THE BAHAMAS OVER THE STRAITS WILL BE IN DOUBT FOR THE NEXT FEW DAYS... BUT MARINERS SHOULD BE PREPARED FOR CAUTIONARY OR SCA CONDITIONS FOR THE MIDDLE OF NEXT WEEK. && .AVIATION... VFR CONDITIONS WILL DOMINATE AT MARATHON AND KEY WEST TERMINALS THROUGH THE FORECAST PERIOD. DEVELOPING CLOUD LINE WITH ATTENDANT SHOWERS AND THUNDERSTORMS WILL ALLOW FOR BRIEF PERIODS OF IFR AT MARATHON AND MVFR AT KEY WEST. LIGHT WINDS FROM THE NORTH NORTHEAST AT BOTH TERMINALS...BUT WILL BE VARIABLE AT TIMES. CONVECTIVE ENVIRONMENT STABILIZES AROUND 01Z. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...NONE. GM...NONE. && $$ |
| #531560 (Received by flhurricane at: 4:09 PM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 407 PM EDT FRI AUG 3 2012 .SYNOPSIS... VERY WARM AND HUMID WEATHER WILL PERSIST THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND THUNDERSTORMS...BUT SHOWERS AND THUNDERSTORMS ARE MORE LIKELY MONDAY WHEN A COLD FRONT CROSSES SOUTHERN NEW ENGLAND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST BY THURSDAY. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... 4 PM UPDATE... DESPITE 2500 J/KG OF ML CAPE AND ML LAPSE RATES OF 6-6.5C/KM BEING OBSERVED ACROSS MUCH OF INTERIOR SOUTHERN NEW ENGLAND AT 3 PM...THE LACK OF FORCING AND DEEP LAYER SHEAR HAS PRECLUDED CONVECTION SO FAR THIS AFTERNOON. DEEPER CU AND TCU CONFINED TO NORTHERN NEW ENGLAND WHERE HIGHER TERRAIN AND ASSOCIATED DIFFERENTIAL HEATING IS PROBABLY ENHANCING MESOSCALE ENVIRONMENT. SOME OF THIS CONVECTION MAY SLIDE SOUTH INTO SOUTHWEST NH AND NORTHERN MA...BUT THE WINDOW IS CLOSING AS CONVECTION IS SLOW TO INITIATE AND INSTABILITY WANES TOWARD 7-8 PM. THE OTHER SCENARIO IS THAT THIS CONVECTION MAY ERODE AS IT LEAVES THE HIGH TERRAIN. NEVERTHELESS THE MAIN HAZARD WITH ANY SHOWER/TSTM WILL BE HEAVY RAIN. ALTHOUGH THIS SHOULD BE SHORT LIVED GIVEN THE LACK OF DEEP LAYER WHICH WILL RESULT IN PULSE TYPE STORMS. OTHERWISE A MAINLY DRY...WARM AND MUGGY EVENING AND OVERNIGHT AHEAD. PATCHY FOG/STRATUS MAY REDEVELOP LATER TONIGHT ALONG THE SOUTH COAST AND IN THE INTERIOR VALLEYS. && .SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/... SAT... TRICKY FORECAST TOMORROW AS ALL MODEL GUIDANCE /TO VARYING DEGREES/ HAS QPF ACROSS THE AREA AND THEN LIFTING NORTHWARD WITH TIME. THIS SEEMS SOMEWHAT REASONABLE AS WEAK SURFACE TROUGH LIFTS NORTH AS A WARM FRONT. SO THIS BOUNDARY COULD PROVIDE A FOCUS FOR CONVECTION. HOWEVER PATTERN RECOGNITION WOULD SUGGEST A CAPPED ENVIRONMENT WITH RISING MID LEVEL HEIGHTS AS SUBTROPICAL RIDGE BUILDS NORTHWEST INTO SOUTHERN NEW ENGLAND. IN ADDITION MID LEVEL FLOW IS ANTICYCLONIC PROVIDING SUBSIDENCE. MOS POPS REFLECT THIS IDEA WITH ONLY SLIGHT CHC POPS FROM THE METNAM AND MAVGFS. THUS WILL GO WITH SLIGHT CHANCE POPS. GIVEN THE LACK OF DEEP LAYER SHEAR THE MAIN RISK WITH ANY TSTM WILL BE BRIEF HEAVY RAIN. MUCH OF THE DAY SHOULD BE DRY ALONG WITH VERY WARM AND HUMID CONDITIONS CONTINUING. SAT NIGHT... MAINLY WARM...MUGGY AND DRY BUT A LOW RISK OF SHOWERS/TSTMS TOWARD SUNDAY MORNING AS MID LEVEL FLOW BECOMES CYCLONIC WITH APPROACHING SHORT WAVE TROUGH. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGHLIGHTS... * QUIET AND MILD SAT NGT * RAIN BECOMING WIDESPREAD SUN-MON ALONG AND AHEAD OF A COLD FRNT * HEAVY RAIN EXPECTED...FLOODING IS A DISTINCT POSSIBILITY * ENERGY OFFSHORE AROUND TUE MORN...QUIET WX EXPECTED INTO WED * ANOTHER DISTURBANCE PSBL INTO THE END OF THE WEEK MODEL DIAGNOSIS... MDL SOLNS ARE STILL TRENDING WITH A PERSISTENT GENERAL PATTERN OF A DEEP POLAR VORTEX ACROSS THE NRN HUDSON BAY RGN WITH A SERIES OF DISTURBANCES ROTATING AROUND THE PERIMETER AND ACROSS THE NERN CONUS. MEANWHILE STRONG RIDGING PERSISTS THRU THE ATLANTIC AND WRN ROCKIES. THE MID-HIGH LATITUDE BLOCKING PATTERN KEEPS AN ACTIVE PATTERN FOR THE FCST. BUT WATCHING A PSBL EWD SHIFT IN THE PATTERN OVER THE NWRN CONUS BY THE FOLLOWING WEEK AS A SERIES OF DISTURBANCES PROMOTE DEEP TROUGHING THRU THE GULF OF ALASKA...CONSEQUENTIALLY SHIFTING THE MAIN RIDGE OF HIGH PRES ACROSS THE CENTRAL CONUS TOWARDS THE ERN CONUS. OVERALL...WHILE MDL SOLN CONTINUITY HAS PERSISTED INTO THE BEGINNING OF NEXT WEEK WITH THE 02/12Z GUIDANCE...THEREAFTER IT HAS REMAINED UNCERTAIN DUE TO RUN TO RUN VARIABILITY OF TIMING/PHASING OF KEY FEATURES ACROSS THE MID-HIGH LATITUDES. HPC HAS EMPHASIZED A MORE CONSENSUS APPROACH WITH EQUAL WEIGHTING OF DETERMINISTIC AND ENSEMBLE MDL SOLNS. OF GREATER CERTAINTY...MDL SOLNS IN BETTER AGREEMENT OF ACTIVITY INITIATING SUNDAY AND CONTINUING SUNDAY NIGHT INTO MONDAY WITH THE APPROACH OF A SFC COLD FRNT. AM STILL CONCERNED OVER THE PROLONGED PERIOD OF SUB-TROPICAL MOISTURE FETCH NEWD ACROSS NEW ENGLAND AHEAD OF THE COLD FRNT /PWATS AROUND 2.25 IN/ WARRANTING THE POSSIBILITY OF FLOOD WATCHES. BETTER AGREEMENT OF THE COLD FRNT AND ATTENDANT ENERGY OFFSHORE BY TUE MORN. AND FINALLY...THERE IS ALSO SLIGHTLY BETTER CONSENSUS OF A FOLLOW UP DISTURBANCE BY THE END OF THE WEEK. SATURDAY NIGHT... CONVECTIVE ELEMENTS DURING THE DAY DIMINISH AS WEAK HIGH PRES TAKES CONTROL. SLY FLOW ENHANCING THRU THE EVNG IN RESPONSE TO THE APPROACHING SYNOPTIC SYS ACROSS THE GRT LKS BY SUNDAY MORN. WILL SEE A SURGE OF LOW 70 DEWPOINTS TOWARDS THE S SHORE OF NEW ENGLAND. CANT RULE OUT THE DEVELOPMENT OF LOW STRATUS AND FOG FOR SHORELINE COMMUNITIES. SHOULD BE A MILD NIGHT WITH MINS RANGING FROM THE UPR 60S TO LOW 70S /MID 70S PSBL/. SUNDAY THROUGH MONDAY... THE COMBINATION OF ENHANCED LOW-MID LVL FLOW OF SUB-TROPICAL AIR FROM THE SERN CONUS ON SUNDAY CONVERGENT ALONG A PSBL PRE-FRONTAL TROUGH...AND DESTABILIZATION OF THE LOCAL BOUNDARY LYR...WARRANTS CHC POPS FOR SUNDAY INTO SUNDAY NGT. ADVERTISED PWATS DURING THIS TIMEFRAME ARE AROUND 2 INCHES WITH MDL SOUNDINGS INDICATED A FAIRLY MOIST ADIABATIC PROFILE WITH THIN ELONGATED CAPE THRU THE ATMOS COLUMN OF 500-1000 J/KG. PRESENT THINKING IS FOR SHOWERS AND THUNDERSTORMS TO INCREASE IN AERIAL COVERAGE THRU THE DAY ACROSS THE MID-ATLANTIC NEWD INTO NEW ENGLAND. BEST POP CHCS WILL BE OVER WRN AND CENTRAL NEW ENGLAND. WHILE STORMS /LIKELY PULSY IN NATURE/ ARE EXPECTED TO BE SUB-SEVERE...HEAVY RAIN WILL BE A THREAT. ACTIVITY SHOULD CONTINUE SUNDAY NIGHT INTO MONDAY ALONG AND AHEAD OF THE COLD FRNT FCST TO SLIDE THRU THE RGN AND OFFSHORE BY TUE MORN. FRONTOGENETICAL FORCING OF CONTINUED LOW-MID LVL SWLY ADVECTION OF SUB-TROPICAL AIR SHOULD LEND TO LIKELY POPS FOR SHOWERS AND THUNDERSTORMS. SOME UNCERTAINTY AS TO WHETHER CLOUDS WILL BREAK ALLOWING FOR DESTABILIZATION OF THE BOUNDARY LYR ON MONDAY. NEVERTHELESS THE POSSIBILITY FOR ELEVATED CONVECTION EXISTS WITH CAPE VALUES HOVERING AROUND 500-1000 J/KG WITHIN A VERY MOIST ADIABATIC ENVIRONMENT. EXPECTED EMBEDDED HEAVIER RAINS WITH PULSE TYPE CONVECTION. PWATS ADVERTISED AROUND 2.25 INCHES AHEAD OF THE COLD FRNT WARRANT THE POSSIBILITY OF FLOODING. TUESDAY AND TUESDAY NIGHT... LOOKS TO REMAIN DRY WITH WEAK HIGH PRES ACROSS THE RGN IN WAKE OF MONDAYS DISTURBANCE SITTING OFFSHORE OF NEW ENGLAND. SLIGHTLY COOLER AND DRIER AIR BUILDS INTO THE RGN /H85 TEMPS AROUND +14C/. LGT AND VRB W/SWLY FLOW. WEDNESDAY THROUGH FRIDAY... A SECOND DISTURBANCE WITH ATTENDANT COLD FRNT IS EXPECTED TO SLIDE THRU THE RGN...USURPING ONCE AGAIN BETTER SUB-TROPICAL MOISTURE FROM THE SERN CONUS. MDL SOLNS VARY WITH OUTCOMES BASED ON EVOLUTION OF MID-LYR FEATURES THRU THE MID-HIGH LATITUDES. AM SOMEWHAT HESITANT TO ACCEPT THE 03/0Z GFS SOLN...RATHER AM MORE FAVORABLE TO THE SIMILAR TRENDS PER 03/0Z CANADIAN AND 02/12Z ECMWF. WILL HINT AT PRECIP FOR WED-THURS...WITH IMPROVEMENT FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND WITH ACTIVITY SHUNTED OFFSHORE BY HIGH PRES BUILDING S OUT OF CANADA. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW... VFR THROUGH THIS EVENING WITH JUST A LOW PROB OF BRIEF MVFR IN ISOLATED TSTM TIL 01Z. TONIGHT...CONFIDENCE IS LOW ON IFR REDEVELOPING. THINKING ANY IFR CONDITIONS WILL BE CONFINED TO SOUTH COAST INCLUDING CAPE COD AND THE ISLANDS. SAT...ANY IFR CAPE COD AND ISLANDS WILL BURN OFF BY MIDDAY. OTHERWISE VFR WITH JUST A LOW PROB OF AN ISOLATED TSTM IN THE AFTN. KBOS TAF...MODERATE CONFIDENCE. VFR WITH JUST A LOW PROB OF A BRIEF MVFR IN TSTM TIL 01Z. OTHERWISE VFR TONIGHT AND SAT. LOW PROB AGAIN OF AN ISOLATED TSTM SAT AFTN. KBDL TAF...MODERATE CONFIDENCE. VFR MUCH OF THE TIME. THE EXCEPTIONS WILL BE A LOW PROB OF BRIEF MVFR IN TSTM TODAY TIL 01Z...THEN LOW PROB OF IFR CONDITIONS IN FOG TONIGHT 06Z-12Z AND THEN AGAIN LOW PROB OF AN ISOLATED MVFR TSTM SAT AFTN. VFR LIKELY SAT NIGHT. OUTLOOK...SUNDAY THROUGH TUESDAY... SUNDAY THROUGH MONDAY...MODERATE CONFIDENCE. INCREASING AERIAL EXTENT OF SHRA/TSRA ALONG AND AHEAD OF AN APPROACHING COLD FRNT FROM THE W. SHRA/TSRA MAY BE HEAVY AT TIMES... ESPECIALLY MONDAY AS THE COLD FRNT TRAVERSES THE TERMINALS... PUSHING OFFSHORE BY TUE MORN. PREVAILING MVFR-VFR...TEMPO IFR VSBY IMPACTS WITH +SHRA/+TSRA. ESPECIALLY DURING EVNG PDS...EXPECTING FOG AND LOW STRATUS ALONG THE S COAST WITH IFR-LIFR IMPACTS. STRONG SLY FLOW WITH GUSTS UP TO 25 KTS THRU THE ENTIRE PD. TUESDAY...MODERATE CONFIDENCE. WLY WIND FLOW. PREVAIL VFR. LESSER CHCS FOR FOG AND LOW STRATUS. && .MARINE... TONIGHT... THINK ANY TSTMS ACROSS NORTHERN NEW ENGLAND WILL DISSIPATE BEFORE REACHING THE SOUTH COAST. OTHERWISE DRY WEATHER SHOULD PREVAIL BUT LOW CLOUDS AND FOG MAY REDEVELOP LATER TONIGHT RESULTING IN A RISK FOR PATCHY DENSE FOG. ALTHOUGH FORECAST CONFIDENCE IS LOW ON AREAL COVERAGE. LIGHT S-SW WINDS PREVAIL. NOT MUCH WIND WAVE OR SWELL. SAT... LIGHT SSW WINDS CONTINUE. NOT MUCH WIND WAVE OR SWELL EXPECTED. VSBY MAY BE REDUCED IN PATCHY DENSE FOG DURING THE MORNING. CONFIDENCE IS LOW ON AREAL EXTENT BUT ANY FOG SHOULD BURN OFF BY MIDDAY. VERY LOW RISK OF A SHOWER/TSTM BUT MUCH OF THE DAY SHOULD BE DRY. SAT NIGHT... MORE OF THE SAME...LIGHT BUT MOIST SSW WINDS YIELDING PATCHY DENSE FOG LATE. OUTLOOK...SUNDAY THROUGH TUESDAY... INCREASING SLY FLOW ALONG AND AHEAD OF AN APPROACHING COLD FRNT WILL RESULT IN SWELL AND HIGH SEAS ACROSS THE S WATERS /WAVE HEIGHTS OF AROUND 7 FT FOR THE OUTER WATERS...WITH 5-7 FT FOR THE INNER WATERS ALONG THE S COAST/. E WATERS WILL GRADUALLY RISE AS WELL. GUSTS UP TO 25 KTS CAN BE EXPECTED BEGINNING LATE SUNDAY THROUGH TUE BY WHICH POINT THE COLD FRNT WILL HAVE SHUNTED E...TRANSITIONING OUT TO SEA. AERIAL EXTENT OF SHOWERS AND THUNDERSTORMS WILL INCREASE THRU THE PD...BEGINNING SUNDAY. SOME OF THESE STORMS...ESPECIALLY ALONG AND AHEAD OF THE COLD FRNT...WILL BE ASSOC WITH HEAVY RAIN AND REDUCED VSBYS. RAINS AND ACTIVITY SHOULD BE E OF THE WATERS BY LATE MORN INTO MIDDAY TUE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ004>006- 009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANK/NOCERA |
| #531561 (Received by flhurricane at: 4:09 PM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 403 PM EDT FRI AUG 3 2012 .SYNOPSIS... A VERY WARM AND HUMID WEEKEND ALONG WITH MAINLY DRY WEATHER IS ON TAP. A COLD FRONT WILL BRING A ROUND OF SHOWERS AND THUNDERSTORMS...MAINLY SUN NIGHT INTO EARLY MON. DRY WEATHER FOLLOWS FOR THE MIDDLE OF NEXT WEEK...WITH PERHAPS A FEW MORE SHOWERS/THUNDERSTORMS NEXT THU AND/OR FRI. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... 215 PM UPDATE... NOT MUCH CHANGE FROM PREVIOUS FORECAST...VERY WARM AND HUMID WEATHER CONTINUES WITH HIGHS ALREADY IN THE L90S AWAY FROM THE IMMEDIATE COAST. FOG/STRATUS HAS FINALLY BURNED OFF ACROSS THE CAPE AND ISLANDS. CONVECTION CONTINUES TO STRUGGLE TO FIRE ANYWHERE ACROSS NEW ENGLAND. ONLY STORMS SO FAR OCCURRED OVER LONG ISLAND NY ON SEABREEZE BOUNDARY. MODELS /INCLUDING 15Z HRRR/ CONTINUE TO FOCUS ANY CONVECTION THIS AFTERNOON INTO EARLY EVENING ACROSS NORTHERN MA INTO SOUTHWEST NH AS WEAK SURFACE TROUGH OVER THIS AREA PROVIDES SOME CONVERGENCE AS A FOCUS. GIVEN DEEP LAYER SHEAR IS ALMOST NIL ANY CONVECTION WILL BE DISORGANIZED AND MAINLY SUB- SEVERE WITH MAIN HAZARD BEING BRIEF HEAVY RAIN. && .SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/... ISOLATED SHOWERS/STORMS WILL BE SLOW TO DIMINISH THIS EVENING DESPITE LOSS OF DAYTIME HEATING DUE TO PLENTY OF LOW LEVEL MOISTURE AND WEAK CONVERGENCE ALONG DISSIPATING FRONT. SHOULD SEE ANOTHER NIGHT OF LOW CLOUDS AND PATCHY FOG...MAINLY NEAR S COAST. USED A BLEND OF GFS/NAM MOS WHICH ARE CLOSE TO EACH OTHER. COLD FRONT WILL HAVE WASHED OUT OVER SOUTHERN NEW ENGLAND SAT...BUT SHOULD STILL BECOME A FOCUS FOR SCATTERED SHOWERS AND STORMS ONCE AGAIN. MODELS INDICATE THIS MAY BEGIN A BIT EARLIER THAN TODAY...BY MID TO LATE MORNING...AS SOME WEAKENING UPSTREAM CONVECTION COMES INTO PLAY. LOOKS LIKE ANOTHER DAY WITH POTENTIALLY HIGH CAPE AND WEAK SHEAR BUT WITH BETTER MID LEVEL LAPSE RATES...SO POTENTIAL FOR GUSTY WINDS AND HAIL MAY BE A LITTLE HIGHER THAN TODAY. LEANED CLOSER TO GFS MOS FOR HIGHS GIVEN EXPECTED CLOUD COVER AND A POSSIBLE EARLIER START TO CONVECTION...IN 80S TO AROUND 90. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGHLIGHTS... *SHOWERS/STORMS LIKELY SUN NIGHT AND/OR EARLY MON WITH HEAVY RAINFALL *SEASONABLE AND MAINLY DRY WEATHER FOR THE MIDDLE OF NEXT WEEK *A FEW SHOWERS/STORMS POSSIBLE AGAIN BY LATE NEXT WEEK DETAILS... SUNDAY AND MONDAY... LOW CONFIDENCE ON TIMING OF THE BULK OF THE PRECIPITATION AS CONSIDERABLE MODEL DIFFERENCES REMAIN. EXPECT MUCH OF THE DAYLIGHT HOURS TO BE DRY ON SUNDAY...OTHER THAN PERHAPS A FEW BRIEF SPOT SHOWERS/THUNDERSTORMS. THE BULK OF THE ACTIVITY SHOULD ARRIVE SOMETIME SUNDAY NIGHT AND POSSIBLY INTO EARLY MONDAY AHEAD OF THE COLD FRONT. THE MAIN CONCERN WITH THIS ACTIVITY WILL BE HEAVY RAINFALL/LOCALIZED FLOODING GIVEN PWATS ON THE ORDER OF 2 TO 2.5 INCHES. SEVERE WEATHER POTENTIAL LOOKS LOW GIVEN WEAK MID LEVEL LAPSE RATES AND AN UNFAVORABLE TIME OF ARRIVAL. HOWEVER...CAN/T COMPLETELY RULE OUT A FEW STRONG THUNDERSTORMS. TUESDAY AND WEDNESDAY... A WEAK RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION BEHIND THE COLD FRONT. DRY WEATHER SHOULD DOMINATE OVER THIS TIME ALONG WITH FAIRLY SEASONABLE TEMPERATURES. THURSDAY AND FRIDAY... UPPER LEVEL/COLD FRONT WILL BE APPROACHING FROM THE WEST. THIS WILL BRING THE CHANCE OF A ROUND OR TWO OF SCATTERED SHOWERS/THUNDERSTORMS...BUT LOW CONFIDENCE ON TIMING. ALSO...NOT EXPECTING A WASHOUT AS MUCH OF THE TIME WILL PROBABLY FEATURE DRY WEATHER. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW...MODERATE CONFIDENCE. VFR THROUGH THIS EVENING WITH JUST A LOW PROB OF BRIEF MVFR IN ISOLATED TSTM TIL 01Z. TONIGHT...CONFIDENCE IS LOW ON IFR REDEVELOPING. THINKING ANY IFR CONDITIONS WILL BE CONFINED TO SOUTH COAST INCLUDING CAPE COD AND THE ISLANDS. SAT...ANY IFR CAPE COD AND ISLANDS WILL BURN OFF BY MIDDAY. OTHERWISE VFR WITH JUST A LOW PROB OF AN ISOLATED TSTM IN THE AFTN. KBOS TAF...MODERATE CONFIDENCE. VFR WITH JUST A LOW PROB OF A BRIEF MVFR IN TSTM TIL 01Z. OTHERWISE VFR TONIGHT AND SAT. LOW PROB AGAIN OF AN ISOLATED TSTM SAT AFTN. KBDL TAF...MODERATE CONFIDENCE. VFR MUCH OF THE TIME. THE EXCEPTIONS WILL BE A LOW PROB OF BRIEF MVFR IN TSTM TODAY TIL 01Z...THEN LOW PROB OF IFR CONDITIONS IN FOG TONIGHT 06Z-12Z AND THEN AGAIN LOW PROB OF AN ISOLATED MVFR TSTM SAT AFTN. VFR LIKELY SAT NIGHT. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUNDAY AND MONDAY...MODERATE TO HIGH CONFIDENCE. MVFR-IFR CONDITIONS IN LOW CLOUDS AND FOG EARLY SUN WILL PROBABLY TEMPORARILY IMPROVE. HOWEVER...MVFR-IFR CONDITIONS SHOULD OCCUR AGAIN SUN NIGHT/EARLY MON IN SOME SHOWERS/THUNDERSTORMS. TUESDAY AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE IN MAINLY VFR CONDITIONS. && .MARINE... FAIRLY CONFIDENT WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH SAT. SW WINDS GUST TO 20KT ALONG S COAST THIS AFTERNOON...WHICH INCLUDES BUZZARDS BAY AND VINEYARD SOUND...BUT PROBABILITY OF REACHING 25KT IS LOW. SEAS WILL CONTINUE TO BUILD SLOWLY ON S COASTAL WATERS DUE TO PERSISTENT SW FLOW BUT ARE NOT EXPECTED TO REACH 5 FT. MAIN HAZARDS INCLUDE SCATTERED TSTMS THIS AFTERNOON AND SAT AFTERNOON...MAINLY FROM NARRAGANSETT BAY TO BOSTON HARBOR AND MERRIMACK RIVER...AND PATCHY DENSE FOG ON S COASTAL WATERS LATE TONIGHT AND SAT MORNING. MODERATE TO HIGH CONFIDENCE. SUNDAY AND MONDAY... INCREASING SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL BUILD SEAS TO ABOVE SCA THRESHOLDS ACROSS THE SOUTHERN WATERS LATE SUN THROUGH MON NIGHT. IN ADDITION...WIND GUSTS OF 20 TO 25 KNOTS CAN BE EXPECTED. THE OTHER BIG CONCERNS FOR MARINERS WILL BE AREAS OF FOG AND THE POTENTIAL FOR SOME THUNDERSTORMS SUN NIGHT INTO MON. TUESDAY AND WEDNESDAY... ANY LINGERING SCA FOR SEAS SHOULD DIMINISH ACROSS THE SOUTHERN WATERS DURING THE DAY TUE. OTHERWISE...RELATIVELY WEAK PRESSURE GRADIENT SHOULD KEEP WINDS AND SEAS BELOW SCA THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ004>006- 009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANK |
| #531559 (Received by flhurricane at: 4:08 PM 03.Aug.2012) AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 1000 AM HST FRI AUG 3 2012 .SYNOPSIS... MODERATE TRADE WINDS WILL PREVAIL THROUGH THE WEEK. CONDITIONS WILL REMAIN ON THE DRY SIDE OF AVERAGE...WITH MOST SHOWERS CONFINED TO WINDWARD SLOPES...AS WELL AS THE KONA SLOPES OF THE BIG ISLAND EACH AFTERNOON. && .DISCUSSION... TRADE WINDS WILL HOLD AT MODERATE STRENGTH ACROSS THE ISLANDS THROUGH AT LEST EARLY NEXT WEEK. THE SYNOPTIC PATTERN OVER THE NORTH PACIFIC IS RATHER UNUSUAL. PERSISTENT TROUGHING THROUGH THE DEPTH OF THE ATMOSPHERE LINGERS ABOUT 900 MILES NORTH OF THE ISLANDS AND EXTENDS TO THE WEST SOUTHWEST TO JUST NORTH OF MIDWAY ATOLL. THIS FEATURE HAS SPLIT THE SUBTROPICAL HIGH THAT NORMALLY RESIDES TO THE NORTH OF HAWAII...BUT THE PRESSURE GRADIENT OVER THE ISLANDS REMAINS STRONG ENOUGH TO PRODUCE MODERATE TRADES. THIS PATTERN WILL CHANGE LITTLE THROUGH EARLY NEXT WEEK...ALLOWING TRADES TO HOLD MORE OR LESS AT THE CURRENT STRENGTH. RAINFALL WILL FOLLOW A TYPICAL WINDWARD AND MAUKA PATTERN THROUGH MUCH OF THE UPCOMING WEEK. THE ISLANDS LIE UNDER A TRANSITION ZONE BETWEEN THE ABOVE MENTIONED MID TO UPPER LEVEL TROUGH AND STRONG UPPER LEVEL RIDGING TO THE SOUTH. THIS WILL MAINTAIN STABLE CONDITIONS OVER THE ISLANDS...ALTHOUGH THE INVERSION MAY BE A BIT HIGHER AND SHOWER CHANCES SLIGHTLY GREATER NEAR KAUAI AT TIMES. THE UPWIND TRADE FLOW LOOKS TO REMAIN SLIGHTLY DRIER THAN AVERAGE...SO EXPECT RAINFALL TOTALS TO REMAIN MODEST. THE STATE WILL EXPERIENCE PERIODS OF HIGH CLOUDS THROUGH EARLY NEXT WEEK...MAINLY ACROSS THE NORTHERN ISLANDS. FORECAST MODELS ARE SHOWING A SURFACE LOW DEVELOPING IN THE ABOVE MENTIONED UPPER LEVEL TROUGH SOMEWHERE BETWEEN MIDWAY AND LAYSAN ON SATURDAY OR SUNDAY. PORTIONS OF THE NORTHWEST HAWAIIAN ISLANDS WILL LIKELY EXPERIENCE THUNDERSTORMS AND GUSTY WINDS INTO MONDAY. THIS FEATURE WILL HAVE NO IMPACT HERE ON THE MAIN HAWAIIAN ISLANDS ASIDE FROM PERIODS OF HIGH CLOUDS THROUGH EARLY NEXT WEEK. && .MARINE... NO MARINE ADVISORIES ARE IN EFFECT...BUT BORDERLINE WINDS WILL PERSIST ACROSS THE TYPICALLY WINDY WATERS AND CHANNELS SURROUNDING THE BIG ISLAND AND MAUI THROUGH EARLY NEXT WEEK. ONLY SMALL SWELLS ARE IN STORE...INCLUDING SOME POSSIBLE ENERGY FROM THE WEST DURING THE FIRST PART OF NEXT WEEK. SEE THE COLLABORATIVE NEARSHORE SWELL AND WIND FORECAST FOR DETAILS. && .AVIATION... PREDOMINANTLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES...WITH ISOL MVFR CIGS ON BIG ISLAND WINDWARD SLOPES. NO AIRMETS ARE IN EFFECT. && .FIRE WEATHER... THE KEETCH BYRAM DROUGHT INDEX /KBDI/ MEASURED AT HONOLULU WILL TOP THE CRITICAL 600 MARK THIS WEEKEND. THIS INDEX IS CRUCIAL FOR FIRE WEATHER WATCH AND RED FLAG WARNING DECISION MAKING. THE WINDY AND DRY CONDITIONS NEEDED FOR THESE PRODUCTS IS NOT ANTICIPATED THROUGH AT LEAST EARLY NEXT WEEK. && .HFO WATCHES/WARNINGS/ADVISORIES... NONE. && $$ |
| #531558 (Received by flhurricane at: 4:08 PM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 405 PM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL INTO EARLY NEXT WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A STATIONARY FRONT WILL STALL NORTH OF THE AREA MID TO LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... ISOLATED SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP ALONG THE SEABREEZE IN SOUTHEAST SOUTH CAROLINA EARLY THIS EVENING ALONG WITH A FEW ISOLATED SHOWERS OVER INLAND GEORGIA WHERE SFC TEMPS HAVE REACHED THE LOW 90S. EXPECT THE FOCUS OF SHOWER/THUNDERSTORM ACTIVITY TO GRADUALLY COVER LOCATIONS WEST OF INTERSTATE 95 IN SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA THIS EVENING. SHEAR PROFILES WILL REMAIN WEAK AND WILL LIKELY RESULT IN PULSE TYPE THUNDERSTORMS GIVEN THE LACK OF UPPER LVL SUPPORT. ACTIVITY MAY GRADUALLY EVOLVE INTO MORE OF A MULTICELL SCENARIO AS CONVECTIVE OUTFLOWS INTERACT...BUT COVERAGE APPEARS LIMITED BASED ON RECENT RADAR TRENDS. SBCAPES BETWEEN 3000-3500 J/KG ALONG WITH DCAPES BETWEEN 600-1000 J/KG SUPPORT A FEW THUNDERSTORMS WITH DAMAGING WINDS. HOWEVER...THE THREAT OF STRONGER ACTIVITY SHOULD DIMINISH QUICKLY AROUND SUNSET. ANY SHOWERS/THUNDERSTORMS THAT HAVE DEVELOPED THIS AFTERNOON/EVENING WILL LIKELY DIMINISH A FEW HOURS AFTER SUNSET...AND LEAD TO A DRY FORECAST OVERNIGHT. LOWS TEMPS WILL RANGE IN THE LOW/MID 70S...WITH UPPER 70S/LOWER 80S ALONG THE IMMEDIATE COAST. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... A DEEP LAYER RIDGE...STRETCHING FROM THE ATLANTIC...WESTWARD ACROSS THE SOUTHERN AND CENTRAL U.S....WILL PERSIST THROUGH THE PERIOD. A TROPICAL WAVE WELL SOUTH OF THE AREA OVER THE BAHAMAS...IS EXPECTED TO REMAIN SOUTH OF THE REGION AS IT MOVES WESTWARD ACROSS CENTRAL FLORIDA AND THEN INTO THE WESTERN GULF OF MEXICO BY EARLY NEXT WEEK. THE GLOBAL MODELS KEEP THIS TROPICAL WAVE WEAK...AND PUSH THE NORTHERN FRINGE OF THE ASSOCIATED MOISTURE ACROSS THE REGION SATURDAY AND SUNDAY...THEN WEST OF THE REGION BY LATER SUNDAY AND MONDAY. HOWEVER...THE NAM IS MUCH SLOWER WITH THE PROGRESSION OF MOISTURE ASSOCIATED WITH THIS TROPICAL WAVE. THE NAM BRINGS IN THE BEST MOISTURE ACROSS THE AREA LATE SATURDAY NIGHT...THEN PERSISTING THROUGH MONDAY. IF THE NAM IS MORE CORRECT...POPS WILL NEED TO BE RAISED FOR SUNDAY AND MONDAY. WILL CONTINUE TO MONITOR LATER NAM SOLUTIONS. FOR NOW...HAVE KEPT GENERALLY CLIMO /CHC/ POPS...CENTERED AROUND THE AFTERNOON/EVENING HEATING...BUT AS MENTIONED ABOVE...POPS MAY NEED TO BE NUDGED HIGHER IS DEEPER MOISTURE ASSOCIATED WITH THE NORTHERN FRINGE OF THE TROPICAL WAVE IMPACTS THE REGION THIS WEEKEND. SOUTHEAST LOW LEVEL FLOW SHOULD HELP TO FOCUS SCATTERED AFTERNOON/EVENING CONVECTION INLAND. WITH NO APPRECIABLE UPPER LEVEL FEATURES TO FORCE CONVECTION...EXPECT MESOSCALE BOUNDARIES AND SEA BREEZE TO BE THE PRIMARY FOCUS FOR CONVECTION. TEMPS EXPECTED TO NEAR NORMAL THROUGH THE PERIOD...HIGHS IN THE LOWER 90S AND LOWS IN THE MID 70S. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UPPER LEVEL RIDGING WILL BEGIN TO WEAKEN EARLY NEXT WEEK...AS A TROUGH ALOFT AND SEVERAL SHORTWAVES MOVE ACROSS THE NEW ENGLAND STATES. AN ASSOCIATED COLD FRONT WILL LIKELY STALL WELL TO THE NORTH OF THE FORECAST AREA BY THE MIDDLE OF NEXT WEEK. AT THE SURFACE...THE INLAND TROUGH COULD BECOME MORE PROMINENT BETWEEN SURFACE HIGH PRESSURE OVER THE CENTRAL UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. CONSIDERING THE INCREASED FORCING FROM THE STALLED FRONT TO THE NORTH...COMBINED WITH INFLUENCES FROM THE LEE TROUGH AND BOUNDARY/SEABREEZE INTERACTIONS...CONVECTIVE POTENTIAL COULD BE GREATER THROUGH THE EXTENDED PERIOD. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS...WITH HIGH TEMPERATURES IN THE LOW TO MID 90S DURING THE AFTERNOON FALLING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... PRIMARILY VFR AT BOTH TERMINALS. ONCE AGAIN...THUNDERSTORMS WILL BE AROUND BOTH KCHS AND KSAV EARLY THIS EVENING BUT COVERAGE AND INTENSITY LOOK TO BE LESS TODAY COMPARED TO THE LAST FEW DAYS. THE CONTINUOUS SOUTHERLY FLOW TODAY SHOULD LIMIT THE CONVERGENCE WITH THE SEABREEZE. HOWEVER...THE PRESENCE OF OUTFLOW BOUNDARIES FROM PREVIOUS STORMS COULD TRIGGER THUNDERSTORM DEVELOPMENT. MODELS HAVE THE BULK OF THE ACTIVITY FURTHER INLAND...THUS...WILL HOLD OFF ON THUNDER OVER THE TERMINALS. EXTENDED AVIATION OUTLOOK...VFR EXPECTED TO PREVAIL. ISOLATED AFTERNOON CONVECTION POSSIBLE EACH DAY...WITH BRIEF PERIODS OF MVFR POSSIBLE. && .MARINE... MARINE CONDITIONS WILL REMAIN QUIET OVERNIGHT AS ATLANTIC HIGH PRESSURE EXPANDS OVER THE COASTAL WATERS. CONDITIONS WILL REMAIN WELL BELOW SMALL CRAFT ADVISORY THRESHOLDS AS A BROAD SOUTHERLY FLOW REGIME DOMINATES WITH WINDS GENERALLY 10-15 KT AND SEAS 2-3 FT. A ATLANTIC RIDGE OF HIGH PRESSURE WILL REMAIN CENTERED JUST NORTH OF THE REGION THROUGH THE WEEKEND...THEN DRIFT SOUTHWARD OVER THE REGION MONDAY THROUGH WEDNESDAY. SOUTHEAST WINDS OF 15 KTS OR LESS AND SEAS 4 FT OR LESS EXPECTED THROUGH THE PERIOD. A WEAK TROPICAL WAVE IS EXPECTED TO MOVE WELL SOUTH OF THE REGION ACROSS CENTRAL FLORIDA THIS WEEKEND AND INTO EARLY NEXT WEEK. THERE COULD BE AN INCREASE OF SHOWERS AND THUNDERSTORMS BY LATER THIS WEEKEND AS THE MOISTURE ASSOCIATED WITH THIS WAVE GLANCES THE REGION. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531554 (Received by flhurricane at: 3:56 PM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 354 PM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TODAY AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 445 PM FRI...CONVECTION THAT BEGAN ALONG A WEAK CONVERGENCE LINE FROM PENDER COUNTY NORTH TO GREENE COUNTY EARLIER TODAY HAS MOVED OFF TOWARDS BEAUFORT AND MARTIN COUNTIES...AND HAS WEAKENED. HAVE TEMPERED BACK POPS TO REFLECT LATEST RADAR TRENDS. TEMPS AND DEWPOINTS ARE FAIRLY CLOSE TO LATEST OBS TO NO CHANGES NEEDED. LATEST MSAS ANALYSIS INDICATES A WEAK UPPER LEVEL VORTMAX ACROSS EASTERN NC MIGRATING NORTH...ASSOCIATED WITH A WEAK UPPER LOW WHICH WILL GRADUALLY LIFT OUT TO THE NORTH TONIGHT. EXPECT SCATTERED TSTMS TO CONTINUE PROGRESSING NE SLOWLY...THEN WANE THIS EVENING WITH LOSS OF DAYTIME HEATING. OVERNIGHT SHOULD SEE DIMINISHING SHOWERS AND THUNDERSTORMS INLAND WITH WIDELY SCATTERED SHOWERS AND TSTMS POSSIBLE OFF THE COAST. SW FLOW WILL KEEP TEMPS MILD OVERNIGHT WITH LOWS IN THE LOW 70S INLAND TO MID/UPPER 70S ALONG THE COAST. && .SHORT TERM /SATURDAY/... AS OF 340 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON HOURS. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL SHOWERS AND THUNDERSTORMS. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM /THROUGH 12Z SATURDAY/... AS OF 145 PM FRI...MAINLY VFR CONDITIONS EXPECTED TODAY ALTHOUGH MAY SEE BRIEF MVFR IN REDUCED VSBYS AND CEILINGS DUE TO CONVECTION MAINLY FOR OAJ/EWN/ISO. GUIDANCE SUGGEST FOG FORMATION OVERNIGHT GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER. ONLY MINOR MVFR HAS BEEN OBSERVED RECENTLY SO HEDGED TOWARDS CLIMO OF RECENT NIGHTS AND KEPT LOW MVFR FOR FOG OVERNIGHT. SAT WILL SEE CONTINUED S FLOW WITH DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/ AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH LOCALLY LOWER CEILINGS/VISIBILITIES. && .MARINE... SHORT TERM /THROUGH SATURDAY/... AS OF 430 PM FRI...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE SOUTHERLY WINDS 8-12 KNOTS WITH MEDIUM PERIOD SWELLS 2-3 FEET AT 8-9 SECONDS. GOOD BOATING CONDITIONS ARE EXPECTED THROUGH SAT WITH LIGHT S/SW WINDS. WAVEWATCH AND LOCAL SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TONIGHT THROUGH SATURDAY. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/ AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND. THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DAG |
| #531553 (Received by flhurricane at: 3:56 PM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 348 PM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM FRIDAY...AFTER A BIT OF A FLURRY OF ACTIVITY ACROSS PENDER COUNTY...CONVECTION BEHAVING MUCH MORE AS ANTICIPATED THIS AFTERNOON. ACTIVITY GENERALLY CONFINED TO THE SEA BREEZE UP AND DOWN THE COAST. STORM MOTION FORECAST TO BE ABOUT 2 KT WITH SPEEDS NO HIGHER THAN 20 KT THROUGH THE COLUMN...BUT IN VASTLY OPPOSING DIRECTIONS THROUGH THE VERTICAL. LACK OF ANY FORCING BEYOND THE SEA BREEZE HAS KEPT STORMS BELOW SEVERE LIMITS WITH A FEW REPORTS OF SUB SEVERE HAIL AND SOME KLTX WIND SPEEDS ESTIMATED IN THE 30-40MPH RANGE. LOW LCLS/HIGH LOW-LVL RH ALSO ALLOWED MOST STORM OUTFLOWS TO HAVE SHELF CLOUDS...ONE OBSERVED HERE AT THE WFO. THE MID LEVEL LOW OVER THE REGION HAS SHOWN LITTLE MOVEMENT AND WILL ONLY GRADUALLY START TO LIFT TO THE NORTH OVERNIGHT. THE RESULTING HEIGHT RISES PAIRED WITH DIURNAL LOSS OF HEATING SHOULD ALLOW FOR STORMS TO BE GONE BY SUNSET. DUE TO THE EXITING OF THE SHORTWAVE STORMS ARE NOT EXPECTED TO REDEVELOP OVERNIGHT...PERHAPS NOT EVEN OVER THE WATER. PATCHY FOG OVERNIGHT POSSIBLE ESPECIALLY IN AREAS WHERE RAINFALL OCCURRED. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...AMPLIFICATION OF THE BERMUDA RIDGE WILL BRING SUBSIDENT DRYING ALOFT TO THE REGION SATURDAY...WHICH WILL LIKELY SQUELCH TSTMS INTO AN ISOLATED CATEGORY. LOW-LEVEL MOISTURE WILL LINGER ACROSS THE EASTERN CAROLINAS IN SOUTHERLY MOIST FLOW TO 700 MB. SURFACE HEATING AND THE SEA BREEZE FRONT SHOULD INTERACT WITH THIS MOISTURE TO PRODUCE ISOLATED AFTERNOON CONVECTION. IT IS NOT COMPLETELY CLEAR IF THE DRYNESS COULD RESULT ONLY IN SHRA AS OPPOSED TO TSTMS...BUT HAVE INCLUDED THUNDER DUE TO STRONG SFC HEATING. SUNDAY IS INTERESTING...IN THAT MOISTURE DEEPENS AND A WEAK TROPICAL WAVES MOVES INTO FLORIDA...ADVERTISING COASTAL SHOWERS ENCROACHING MAINLY SOUTH CAROLINA. HAVE RAISED POP VALUES SUNDAY BUT DUE TO THE UNCERTAINTY OF THE TROPICAL WAVES NORTHERN INFLUENCE...HAVE HELD POP VALUES IN THE ISOLATED TO SCATTERED CATEGORY SUNDAY. BOTH DAYS WILL BE SIMILAR IN TEMPERATURE...BUT SATURDAY COULD BE A FEW DEGREES WARMER DUE TO LESS CLOUDS AND MORE COLUMN SUBSIDENCE. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 3 PM FRIDAY...LACK OF ANY SIGNIFICANT 5H TROUGH COMBINED WITH WEAK RIDGING AT THE SURFACE AND ALOFT WILL KEEP A WEAK COLD FRONT STALLED NORTHWEST OF THE REGION FOR MUCH OF THE PERIOD. DURING THE MIDDLE OF NEXT WEEK A SHORTWAVE TROUGH WILL REINFORCE THE 5H TROUGH...PUSHING WHAT IS LEFT OF THE STALLED BOUNDARY TO THE COAST LATE NEXT WEEK. FOR THE FIRST HALF OF THE PERIOD THE BERMUDA HIGH AND STALLED FRONT WILL PRODUCE THE TYPICAL SUMMER PATTERN WITH SEA BREEZE CONVECTION AND STALLED FRONT THE INITIAL FOCUS FOR CONVECTION. RESULTING OUTFLOW BOUNDARIES WILL GENERATE ADDITIONAL STORMS...BUT GIVEN SOME MID LEVEL SUBSIDENCE DO NOT THINK COVERAGE WILL BE ABOVE 30 TO 40...SIMILAR TO CLIMO. LATE IN THE PERIOD TROUGHING ALOFT HELPS PUSH REMAINS OF FRONT TO THE COAST. TROUGH AXIS WEST OF THE AREA LEADS TO DEEP SOUTHWEST FLOW...TAPPING GULF MOISTURE. POP REMAINS IN THE CHANCE REALM THROUGH THE END OF THE PERIOD GIVEN LOW LEVEL CONVERGENCE AND PRECIPITABLE WATER VALUES OVER 2 INCHES. TEMPERATURES WILL BE WITHIN A FEW DEGREES OF CLIMO THROUGH THE PERIOD...UPPER 80S TO LOW 90S AND LOW TO MID 70S. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... AS OF 20Z...ISOLATED TO SCATTERED STORMS HAVE FORMED ALONG THE SEA BREEZE NEAR ILM AND TO THE WEST OF CRE AND MYR. CONVECTIVE POTENTIAL AT THESE SITES PRESENTLY AT ITS HIGHEST WITH THE FOCUS SHIFTING WESTWARD AS THE AFTERNOON PROGRESSES. HAVING SAID THAT...THE PROBABILITY AT EACH SITE IS LOW ENOUGH THAT INCLUSION IN THE TAFS IS NOT WARRANTED. PILOTS NAVIGATING TO AREA TERMINALS ARE LIKELY TO ENCOUNTER CONVECTION ENROUTE THOUGH. AFTER SUNSET...STORMS SHOULD WANE AND THE REMAINDER OF THE TAF PERIOD IS EXPECTED TO BE VFR. LIGHT AND VARIABLE WINDS ARE EXPECTED AFTER SUNSET WITH DAYLIGHT WINDS DURING THE PERIOD EXPECTED TO BE S-SE INVOF 10KT. EXTENDED OUTLOOK...PREDOMINANTLY VFR BUT THERE IS A CHANCE OF MORNING MVFR VSBYS IN BR AND A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM FRIDAY...SOUTH TO SOUTHWESTERLY WINDS SO OFTEN OBSERVED LOCALLY THIS TIME OF YEAR WILL CONTINUE THROUGH THE PERIOD. WEST ATLANTIC HIGH PRESSURE TO REMAIN RATHER HEALTHY AND SOME VERY WEAK INLAND TROUGHINESS IN PLACE THIS AFTERNOON WILL WEAKEN THIS EVENING...WASHING OUT COMPLETELY DURING THE OVERNIGHT HOURS. THE 2 TO 3FT SEAS CURRENTLY WIDESPREAD ACROSS THE WATERS WILL REMAIN UNCHANGED THROUGH THE AFTERNOON AND NIGHTTIME...WITH AN AVERAGE PERIOD OF ABOUT 9 SECOND. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...S-SSE WINDS EXPECTED SATURDAY AND SUNDAY...AND INCREASING A BIT INTO SUNDAY. THIS FETCH WILL BUILD SEAS FROM 2-3 FT MUCH OF SATURDAY...TO 3-4 FEET SATURDAY NIGHT INTO SUNDAY AS SSE WINDS INCREASE TO AROUND 15 KNOTS BY SATURDAY EVENING. SEAS WILL BE A MIX OF SSE WAVES WITH MIXED WAVE PERIODS OF 6 SECONDS AND 10 SECONDS. STORMS WILL BE ISOLATED SATURDAY...AND MAINLY OVER LAND. BY SUNDAY...INCREASING SHOWERS AND TSTMS OVER THE WATERS MAY BE EXPECTED AS A TROPICAL WAVE MOVES INTO NORTH FLORIDA. THIS ACTIVITY WILL BE FAVORED OVER THE SC WATERS IN CLOSER PROXIMITY TO THE WAVE. NO SMALL CRAFT ADVISORIES ARE EXPECTED THIS WEEKEND. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 3 PM FRIDAY...BERMUDA HIGH AND STALLED DISSIPATING FRONT ACROSS THE CENTRAL CAROLINAS WILL KEEP SOUTHWEST FLOW OVER THE WATERS THROUGH THE PERIOD. EARLY ON...THE GRADIENT WILL BE ILL-DEFINED KEEPING SPEEDS ON THE LOW END OF THE 10 TO 15 KT RANGE. SLIGHT PINCHING OF THE GRADIENT LATE IN THE PERIOD WILL LEAD TO A MARGINAL INCREASE IN SPEEDS...THOUGH WINDS SHOULD REMAIN IN THE 10 TO 15 KT RANGE. SEAS WILL RANGE FROM 2 TO 3 FT FOR MUCH OF THE PERIOD WITH SOME ISOLATED 4 FT POSSIBLE WELL OFF CAPE FEAR. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531552 (Received by flhurricane at: 3:54 PM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 347 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE SOUTHEAST COAST WILL ALLOW FOR WARM AND HUMID CONDITIONS ACROSS THE AREA THROUGH THE WEEKEND. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL ALSO CONTINUE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH THE REGION ON MONDAY RESULTING IN BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... LATEST SATELLITE TRENDS SHOW EXPANDING CU FIELD ACROSS NC/VA AS MOST ORGANIZED ACTIVITY REMAINS CLOSE TO MID LEVEL SHORTWAVE IN KY/TN AND UPPER LEVEL LOW IN SE NC. FEW TOWERS ATTEMPTED TO GO UP JUST SOUTH OF RICHMOND...BUT WARMING ALOFT HAS REALLY LIMITED UPDRAFT STRENGTH THUS FAR. 700MB THETA E RIDGE SET UP ACROSS SE VA/NE NC WITH OBSERVED DEWPOINTS INCREASING INTO THE LOW 70S. LATEST BLENDED PRECIP WATERS HAVE INCREASED TO 1.5 TO 1.6 INCHES. WITH THAT SAID...SUFFICIENT LOW LEVEL MOISTURE EXIST FOR AFTERNOON CONVECTION. THE LIMITING FACTORS SO FAR TODAY HAVE BEEN WARMING ALOFT (REDUCING MID LEVEL LAPSE RATES) WITH 500MB TEMPS PROGGED AROUND 6-7C...AND DRY MID TO UPPER LEVELS...500MB RH AT 20 PCT. MIXED LAYER CAPE INCREASES OF AROUND 1000 J/KG OVER THE PAST 3 HOURS TO AROUND 2000 J/KG SHOULD INITIATE DECENT UPDRAFTS ACROSS THE AREA. LATEST MODEL SOLUTIONS HAVE STRUGGLED HANDLING AFTERNOON CONVECTION SO HAVE OPTED TO LEAVE CURRENT SCATTERED POPS FOR THIS AFTERNOON ALONE. DUE TO WEAK FLOW/SHEAR...LOCALLY HEAVY RAINFALL WILL AGAIN BE POSSIBLE. STORM MERGERS AND STEEP LOW LEVEL LAPSE RATES WILL ALSO PROVIDE THE POSSIBILITY OF LOCALIZED STRONG GUSTY WINDS. LOSS OF DAYTIME HEATING WILL ALLOW FOR A RAPID DECREASE IN COVERAGE THIS EVENING. AFTERNOON TEMPERATURES HAVE REACHED INTO THE UPPER 80S NEAR THE COASTS TO LOW 90S ELSEWHERE. LOCAL HEAT INDICES IN MID/UPPER 90S WITH A FEW LOCALIZED 100 DEG READINGS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... SHORTWAVE TROUGH TO LIFT NE SATURDAY WITH BERMUDA HI PRESSURE EXPANDING WESTWARD. SWLY FLOW ALOFT WILL ALLOW FOR CONTINUED HUMID CONDITIONS WITH ABOVE NORMAL DAYTIME TEMPERATURES. A STRONG MID LEVEL SHORTWAVE WILL APPROACH THE GREAT LAKES REGION THROUGH THE WEEKEND. WEAK MID LEVEL DISTURBANCES WILL COMBINE WITH THE WARM AND HUMID AIRMASS TO PROVIDE ISOLATED/SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. TEMPERATURES THIS WEEKEND WILL RANGE FROM THE UPPER 80S TO LOW/MID 90S UNDER MOSTLY SUNNY TO PARTLY CLOUDY SKIES. HEAT INDICES EXPECTED TO REMAIN BELOW HEAT ADVISORY CRITERIA. A COLD FRONT IS PROGGED TO REACH CENTRAL VA BY MONDAY MORNING/AFTERNOON RESULTING IN MORE ORGANIZED AND WIDESPREAD CONVECTION MONDAY AFTERNOON. ATTM...GFS/ECMWF SOLUTIONS TEND TO BE MORE PROGRESSIVE/DEEPER WITH SFC TROUGH MONDAY THAN NAM/SREF SOLUTIONS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... WE HAVE ARRIVED AT THE TIME OF YEAR WHERE FRONTS HAVE A TUFF TIME MOVING SOUTH OF THE REGION DUE TO THE STRENGTH OF THE BERMUDA HIGH. NEXT WEEK WILL FEATURE ONE SUCH BOUNDARY THAT STALLS AND WEAKENS ACROSS THE REGION BY TUESDAY...LINGERS AS A LEE TROF WEDNESDAY AND THURSDAY WITH ANOTHER FRONTAL BOUNDARY APPROACHING FROM THE NORTH FRIDAY. RESULT WILL BE A TRIGGER FOR CHC POPS EACH DAY...CONCENTRATING ON THE AFTERNOON/EVENING HOURS. BEST MOISTURE AND HIGHEST POPS SEEN MONDAY NIGHT THROUGH WEDNESDAY. SLGHT CHC POPS THURSDAY EXCEPT CHC ACROSS THE SE. SLGHT CHC FRI FOR NOW. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 8-10KT TODAY. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED THROUGH THE AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE. VERY ISOLATED FOG IS POSSIBLE DUE TO RESIDUAL MOISTURE FROM SHOWERS AND TSTMS. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... NO FLAGS AS SRLY FLOW ARND BERMUDA HIGH PRESSURE DOMINATES THROUGH THE WEEKEND. SOME CHANELLING UP THE BAY TONIGHT AND SAT NIGHT WILL KEEP WINDS BTWN 10-15 KTS. INCRG PRESSURE GRADIENT AHEAD OF APPRCHG BOUNDARY/TROF MAY RESULT IN MINIMAL SCA CONDITIONS SUN NIGHT / MON. BOUNDARY STALLS/WEAKENS OVER THE REGION EARLY NEXT WEEK WITH SW FLOW CONTINUING. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...SAM |
| #531551 (Received by flhurricane at: 3:51 PM 03.Aug.2012) AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 245 PM CDT FRI AUG 3 2012 .SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...MID/UPPER LEVEL HIGH PRESSURE CONTINUES TO DOMINATE OUR WEATHER PATTERN THROUGH THE START OF THE WEEKEND. WILL CONTINUE WITH AN OVERALL PERSISTENT FORECAST AS AFTERNOON TEMPERATURES REACH INTO THE TRIPLE DIGITS ALONG AND WEST OF HIGHWAY 281. MOISTURE VALUES INCREASE A BIT ACROSS THE REGION OVERNIGHT INTO SATURDAY...THUS WILL MAINTAIN THE MENTION OF PRECIPITATION FOR MORNING SHOWERS OVER THE WATERS...AND SLIGHT CHANCE OF CONVECTION DURING THE AFTERNOON. HOWEVER...ANY ACTIVITY WILL BE VERY ISOLATED IN NATURE AS SUBSIDENCE REMAINS IN PLACE AND THERE IS NO MAJOR FOCUS FOR LIFT. OVERNIGHT CONDITIONS WILL CONTINUE WARM AND MUGGY THROUGH THE FORECAST PERIOD AS WELL. && .LONG TERM (SUNDAY THROUGH FRIDAY)...CONCUR WITH THE GFS/ECMWF THAT THE UPPER RIDGE WILL RETROGRADE TOWARD THE NW DRG THE PERIOD. THUS...SUBSIDENCE EXPECTED TO DECREASE OVER THE CWA/MSA. FURTHER... CONCUR WITH THE GFS/NAM THAT A REGION OF GREATER MSTR...CURRENTLY OVER THE CNTRL GULF...WILL ENTER THE CWF/MSA EARLY IN THE PERIOD. THE COMBINATION OF THE FOREGOING/AFTN INSTABILITY (GFS CAPE/CIN) WILL CONTRIBUTE TO AT LEAST ISOLD CONVECTION. ANTICIPATE CONVECTION TO CONTINUE DRG THE PERIOD YET WITH THE GREATEST CHANCE OVER THE ERN CWA/MSA TUESDAY-WEDNESDAY. (EXPECT CONVECTION OVER THE COASTAL WATERS TO BE PRIMARILY NOCTURAL.) EXPECT MAX TEMPS TO FALL ONLY SLIGHTLY MONDAY-WEDNESDAY OWING TO GREATER MSTR...YET AT LEAST 100-105F MAX HEAT INDEX VALUES. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 78 97 78 96 78 / 10 10 10 20 10 VICTORIA 75 95 75 96 75 / 10 20 10 30 10 LAREDO 79 104 79 103 79 / 0 10 0 10 10 ALICE 76 102 76 99 76 / 10 10 10 20 10 ROCKPORT 80 91 80 90 81 / 10 20 10 30 10 COTULLA 76 103 75 102 75 / 0 10 0 10 10 KINGSVILLE 77 100 77 99 76 / 10 10 10 20 10 NAVY CORPUS 80 91 80 89 81 / 10 10 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531550 (Received by flhurricane at: 3:51 PM 03.Aug.2012) AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 347 PM EDT FRI AUG 3 2012 .SYNOPSIS... AN AREA OF HIGH PRESSURE IN THE WESTERN ATLANTIC WILL REMAIN IN PLACE THROUGH SATURDAY. A COLD FRONT IS THEN SCHEDULED TO ARRIVE LATE SUNDAY, BEFORE SLOWLY SHIFTING EASTWARD MONDAY. THIS FRONT MAY STALL NEARBY BEFORE A SECONDARY COLD FRONT ARRIVES WEDNESDAY INTO THURSDAY. THIS FRONT MAY THEN DISSIPATE AS YET ANOTHER COLD FRONT ARRIVES LATE THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... ISOLATED SHOWERS AND THUNDERSTORMS ARE STARTING TO POP UP ACROSS THE AREA THIS AFTERNOON AND WILL CONTINUE INTO THIS EVENING. AS THESE ARE MORE OF INSTABILITY DEPENDENT STORMS, THEY SHOULD START TO DISSIPATE AS THE SUN SETS THIS EVENING. AFTER THE STORMS DISSIPATE, SKIES OPEN UP A LITTLE BIT ALTHOUGH THERE WILL STILL BE SOME HIGHER CLOUDS AROUND OVERNIGHT. TEMPERATURES TONIGHT DROP INTO THE 70S OVERNIGHT WITH SOME UPPER 60S ACROSS THE NORTHERN AREAS. WITH PLENTY OF LOW LEVEL MOISTURE ACROSS THE REGION, FOG MAY BECOME AN ISSUE ONCE AGAIN OVERNIGHT. LOOKS TO BE PATCHY FOG ACROSS THE REGION WITH FOG MORE LIKELY IN AREAS WHERE RAIN HAS FALLEN. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... THE BERMUDA HIGH REMAINS TO THE EAST OF THE AREA AND WILL CONTINUE TO INFLUENCE OUR WEATHER. HOT HUMID AIRMASS REMAINS ACROSS THE REGION WITH A SOUTHERLY FLOW BECOMING A BIT MORE TO THE SOUTHEAST THROUGH THE DAY. WINDS START TO PICK UP LATER IN THE DAY AS LOW PRESSURE STARTS TO PUSH EASTWARD, CREATING A TIGHTER PRESSURE GRADIENT ACROSS OUR AREA. TEMPERATURES SHOULD REACH INTO LOWER 90S ACROSS MOST OF THE AREA WITH SOME UPPER 80S IN THE HIGHER TERRAIN OF NORTHWESTERN NEW JERSEY AND SOUTHERN POCONOS. DEWPOINTS WILL BE SIMILAR TO FRIDAYS AND BE IN THE UPPER 60S TO LOWER 70S. WHILE THIS WILL KEEP IT FEELING HUMID OUTSIDE, HEAT INDEX VALUES LOOK TO FALL SHORT OF ADVISORY LEVELS SO WE ARE NOT EXTENDING ANY HEAT HEADLINES WITH THIS PACKAGE. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... THE OVERALL SYNOPTIC PATTERN IS COMPRISED OF A ROBUST SHORT WAVE TROUGH THAT WILL MOVE FROM THE MIDWEST SATURDAY NIGHT TO THE NORTHEAST SUNDAY NIGHT INTO MONDAY. GIVEN THE STRENGTH OF THIS FEATURE, LOCALLY STRONG TO POTENTIALLY SEVERE CONVECTION MAY OCCUR LATER SUNDAY. THIS SHORT WAVE TROUGH THEN LOOKS TO WEAKEN SOME AS A LARGER TROUGH BECOMES ESTABLISHED ACROSS EASTERN CANADA AND A RIDGE PERSISTS IN THE SOUTHWESTERN ATLANTIC. THIS TROUGH THEN TENDS TO SETTLE SOUTHWARD SOME FROM THE MIDWEST TO THE NORTHEAST. THE OVERALL FLOW THOUGH MAY WEAKEN AS THE MAIN TROUGH WEAKENS NORTHEASTWARD, WHICH MAY END UP LEADING TO A COUPLE OF SURFACE COLD FRONTS SLOWING OR STALLING NEAR OUR REGION FROM LATE MONDAY ONWARD. WE USED MOSTLY A MODEL BLEND APPROACH FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT, THEN FOLLOWED FAIRLY CLOSELY TO HPC GUIDANCE THEREAFTER. HPC USED A GFS/ECMWF BLEND TO WEDNESDAY THEN AN EVEN BLEND OF THE ENSEMBLE MEAN AND NAEFS MEAN FOR THURSDAY AND FRIDAY. FOR SATURDAY NIGHT, ANY ISOLATED TO SCATTERED CONVECTION SHOULD DISSIPATE DURING THE EVENING HOURS AS IT SHOULD BE MOSTLY DRIVEN BY AIRMASS HEATING. THIS SCENARIO LOOKS TO FAVOR ANY CONVECTION TENDING TO HOLD INLAND AND ESPECIALLY FROM INTERSTATE 95 WESTWARD. OTHERWISE, A MUGGY NIGHT WITH SOME LINGERING MAINLY MID TO HIGH LEVEL CLOUDS. GIVEN THE AMOUNT OF LOW-LEVEL MOISTURE FORECAST TO BE IN PLACE ALONG WITH A LIGHT SOUTHERLY FLOW, PERHAPS SOME PATCHY STRATUS DEVELOPS. A ROBUST SHORT WAVE TROUGH WILL THEN START TO APPROACH LATE, AND SOME LOW-LEVEL WAA MAY ALLOW FOR A SMALL CHC FOR CONVECTION TO REDEVELOP OVERNIGHT. OUR CONFIDENCE IN THIS IS LOW GIVEN THE MAIN ASCENT HOLDING BACK WELL TO OUR WEST. FOR SUNDAY AND MONDAY, THIS LOOKS TO POTENTIALLY FEATURE A PERIOD OF ACTIVE CONVECTIVE WEATHER /SUNDAY/. A RATHER ROBUST SHORT WAVE TROUGH WILL BE WORKING EASTWARD FROM THE GREAT LAKES, HOWEVER THE TIMING OF THIS FEATURE LOOKS SLOW ENOUGH TO THROTTLE BACK/DELAY THE POPS SOME FROM WEST TO EAST. THE MODEL GUIDANCE INDICATES A DECENT LOW TO MID LEVEL WIND FIELD ARRIVING FROM THE WEST, ALTHOUGH THE STRONGER SHEAR IS FORECAST TO SLIDE MOSTLY TO OUR WEST AND NORTH AS THE UPPER-LEVEL TROUGH AXIS LIFTS NORTHEASTWARD A BIT. THE GUIDANCE INDICATES THAT PLENTY OF INSTABILITY WILL BE IN PLACE ACROSS OUR AREA, AND WITH AMPLE HEATING TAKING PLACE A PRE-FRONTAL TROUGH SHOULD SET UP. THIS MAY PROVIDE ENOUGH LOW-LEVEL CONVERGENCE FOR ISOLATED TO SCATTERED CONVECTION TO DEVELOP. IT LOOKS HOWEVER THAT WE WILL HAVE TO WAIT FOR THE MAIN ASCENT WITH THE UPPER-LEVEL TROUGH TO ARRIVE TO FORCE MORE ORGANIZED CONVECTION, WHICH MAY TEND TO BE IN THE FORM OF CLUSTERS AND/OR LINE SEGMENTS. THIS TIMING WOULD TEND TO BRING THIS INTO OUR WESTERN ZONES IN THE AFTERNOON AND THEN DURING THE NIGHT ACROSS OUR EASTERN AND SOUTHERN ZONES. WHILE THE CONVECTION MAY WEAKEN DURING THE OVERNIGHT, INSTABILITY HOLDING ON ALONG WITH THE PASSAGE OF THE UPPER-LEVEL TROUGH AND SURFACE COLD FRONT SHOULD BE ENOUGH TO SUSTAIN AT LEAST SOME CONVECTION. GIVEN THE INSTABILITY AND THERMODYNAMIC PROFILES /RELATIVELY HIGH MOISTURE CONTENT AND STEEPENING LOW-LEVEL LAPSE RATES/, SOME OF THE CONVECTION MAY BECOME SEVERE ESPECIALLY IF STORMS CAN INITIATE EARLIER. IN ADDITION, THE SEVERE THREAT MAY TEND TO INCREASE IF ORGANIZED COLD POOLS WITHIN LINE SEGMENTS OR CLUSTERS CAN BECOME ESTABLISHED WHICH WOULD ENHANCE THE DOWNBURST WIND POTENTIAL. THEREFORE, LOCALLY GUSTY TO DAMAGING WINDS LOOK TO BE THE MAIN THREAT. IF STORMS ARE ABLE TO SUSTAIN STRONG UPDRAFTS, THEN LARGER HAIL WOULD ALSO BECOME A CONCERN. DESPITE THE POTENTIAL FOR A LATER ARRIVAL, THERE IS AT LEAST SOME STRONG CONVECTIVE WIND POTENTIAL THEREFORE ADDED GUSTY WINDS IN THE FORECAST. GIVEN A RATHER MOIST AND UNSTABLE AIRMASS, ROBUST ENOUGH UPDRAFTS MAY PRODUCE A LOT OF LIGHTNING, THEREFORE ADDED THIS AS WELL. WE WILL ALSO CONTINUE THE MENTION OF POSSIBLE STRONG TO SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK. BASED ON THE MODEL CONSENSUS, WE SLOWED DOWN THE POP INCREASE FROM WEST TO EAST A DECENT AMOUNT. THE COLD FRONT THEN GRADUALLY SLIDES SOUTHEASTWARD MONDAY WITH SOME SHOWERS AND STORMS POSSIBLY LINGERING MAINLY ACROSS OUR EASTERN AND SOUTHERN ZONES THROUGH MIDDAY. THERE MAY BE ENOUGH OF A SOUTHEASTERLY PUSH FROM AN INCOMING SURFACE HIGH TO REDUCE THE CONVECTIVE THREAT THE FARTHER NORTHWEST ONE GOES ACROSS OUR CWA. AS A RESULT, WE SHAVED THE POPS BACK FROM NORTHWEST TO SOUTHEAST WITH TIME. THE DRIER AIR HOWEVER MAY BE DELAYED IN ARRIVING ACROSS THE BULK OF OUR CWA AS THE SURFACE FRONT MAY TEND TO SLOW OR EVEN STALL. FOR TUESDAY AND WEDNESDAY, AN UPPER-LEVEL TROUGH GENERALLY BECOMES MORE AND MORE ESTABLISHED ACROSS THE NORTHEAST. THIS SHOULD FAVOR THE AFOREMENTIONED COLD FRONT STALLING NEAR THE NORTHERN MID ATLANTIC REGION. THIS BOUNDARY LOOKS TO WASH OUT WITH TIME AS SOME TROUGH AMPLIFICATION OCCURS UPSTREAM AND SENDS A SECONDARY COLD FRONT OUR WAY WEDNESDAY. SOME LOWERING HEIGHTS ALOFT ONCE AGAIN COMBINED ESPECIALLY WITH HEATING AND TERRAIN AFFECTS MAY BE ENOUGH TO ALLOW FOR ISOLATED TO SCATTERED SHOWERS AND STORMS ESPECIALLY WEDNESDAY AFTERNOON AND EVENING. FOR NOW, WE LEANED MORE TOWARD SLIGHT CHC POPS AS COVERAGE LOOKS TO BE LIMITED. FOR THURSDAY AND FRIDAY, AS THE UPPER-LEVEL TROUGH IS MAINTAINED IN THE NORTHEAST, ADDITIONAL ENERGY ROUNDING ITS BASE MAY KEEP THE SURFACE FRONTS SLOW MOVING OR EVEN STALL INTO THE MID ATLANTIC. A LEE SIDE TROUGH MAY BECOME PRESENT DURING BOTH OF THESE DAYS BEFORE ANOTHER SURFACE COLD FRONT ARRIVES LATE THURSDAY AND FRIDAY. THE OVERALL TROUGHING/CYCLONIC FLOW ABOVE SURFACE HEATING MAY LEAD TO SOME MAINLY DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS. THE MAIN FORECAST CHALLENGE THIS FAR OUT IS MOSTLY COVERAGE. GIVEN LOWER CONFIDENCE, WENT WITH SLIGHT CHC TO LOW CHC POPS. AS FOR TEMPERATURES, WE USED MOSTLY A MOS BLEND FOR SATURDAY NIGHT THROUGH MONDAY THEN CLOSER TO HPC GUIDANCE. SOME ADJUSTMENTS WERE THEN MADE AFTER SOME ADDITIONAL COLLABORATION. SUNDAY LOOKS TO BE ANOTHER VERY WARM TO HOT DAY, HOWEVER HEAT INDICES ATTM LOOK TO STAY BELOW ADVISORY CRITERIA EVEN FOR THE PHILADELPHIA METRO AREA. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING. ISOLATED CONVECTION THROUGH THIS AFTERNOON AND EVENING BUT CONFIDENCE IS LOW THAT IT WILL DIRECTLY AFFECT THE TERMINALS. ANYTHING THAT DEVELOPS SHOULD DISSIPATE BY AROUND 00Z. WINDS WILL REMAIN LIGHT AND OUT OF A SOUTHERLY DIRECTION TONIGHT. WINDS SHOULD GO LIGHT AND VARIABLE AT MOST LOCATIONS OVERNIGHT. WHERE IS WIND, IT WILL BE A SLIGHT SOUTHWEST FLOW BECOMING MORE SOUTHEASTERLY TOWARD SATURDAY MORNING. FOG WILL ONCE AGAIN BE AN ISSUE TO DEAL WITH SATURDAY MORNING. PLENTY OF LOW LEVEL MOISTURE WILL REMAIN ACROSS THE REGION AND THE POTENTIAL FOR MVFR, POSSIBLY IFR, FOG WILL EXIST. FOG WILL BE MORE LIKELY IN LOCATIONS WHERE RAIN FALLS. OUTLOOK... SATURDAY NIGHT THROUGH SUNDAY...GENERALLY VFR /SMALL CHANCE FOR POCKETS OF STRATUS LATER SATURDAY NIGHT AND SUNDAY MORNING/, WITH ANY ISOLATED OR SCATTERED THUNDERSTORMS ENDING BY LATE SATURDAY EVENING. THEN, A BETTER CHANCE OF SOME SHOWERS AND THUNDERSTORMS SUNDAY AFTERNOON AND SUNDAY NIGHT AS A COLD FRONT SLOWLY ARRIVES. SOME OF THE STORMS MAY BE GUSTY ALONG WITH LOCAL SUB-VFR CONDITIONS FOR A TIME. A GENERAL SOUTH TO SOUTHWEST WIND SUNDAY AFTERNOON MAY GUST TO ABOUT 20 KNOTS. MONDAY AND TUESDAY...SOME SCATTERED SHOWERS OR THUNDERSTORMS MAY LINGER ESPECIALLY THROUGH MIDDAY MONDAY WITH LOCAL SUB-VFR POSSIBLE. OTHERWISE, VFR WITH ANOTHER LOW CHANCE OF A THUNDERSTORM TUESDAY AFTERNOON MAINLY SOUTH OF A LINE FROM KILG TO KACY. WEDNESDAY...A LOCAL SHOWER OR THUNDERSTORM IS POSSIBLE AS A SECONDARY COLD FRONT SLOWLY ARRIVES. && .MARINE... SEAS AND WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH SATURDAY. HOWEVER, WITH THE GRADIENT STARTING TO TIGHTEN UP, AN INCREASING SOUTHEASTERLY FLOW WILL DEVELOP TOWARD SATURDAY AFTERNOON AND EVENING, INCREASING WINDS AND SEAS SLIGHTLY. OUTLOOK... HIGH PRESSURE CENTERED TO OUR SOUTHEAST WILL ERODE SOME SUNDAY INTO MONDAY AS A COLD FRONT ARRIVES. A SOUTHERLY FLOW AHEAD OF THIS FRONT IS EXPECTED TO INCREASE SUNDAY INTO MONDAY AS THE PRESSURE GRADIENT TIGHTENS. THIS MAY RESULT IN ADVISORY LEVEL WIND GUSTS OCCURRING LATE SUNDAY AFTERNOON AND ESPECIALLY SUNDAY NIGHT. THESE WINDS ARE THEN EXPECTED TO DIMINISH MONDAY. THE INCREASED SOUTHERLY FLOW WILL ALSO BUILD THE SEAS, WHERE HEIGHTS MAY GET TO AROUND 5 FEET ON THE OCEAN SUNDAY NIGHT BEFORE GRADUALLY SUBSIDING MONDAY. SOME THUNDERSTORMS SUNDAY NIGHT MAY BE LOCALLY GUSTY ALONG WITH FREQUENT LIGHTNING. THE CONDITIONS ARE EXPECTED TO BE BELOW ADVISORY CRITERIA TUESDAY AND WEDNESDAY. && .RIP CURRENTS... THE MODERATE RISK OF RIP CURRENTS FOR NEW JERSEY AND LOW FOR DELAWARE CONTINUES THROUGH THIS EVENING. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ067>071. NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ015-017>019. DE...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR DEZ001. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...GORSE |
| #531549 (Received by flhurricane at: 3:48 PM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 336 PM EDT FRI AUG 3 2012 .SYNOPSIS... LARGE HIGH PRESSURE OFF THE ATLANTIC COAST WILL REMAIN STATIONARY THROUGH SATURDAY. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... WARM TEMPS AND HIGH DEW POINTS HAVE RESULTED IN HOT CONDITIONS ACROSS THE AREA...WITH PLENTY OF LOW LEVEL INSTABILITY IN PLACE. WARMING HEIGHTS ALOFT AND LACK OF TRIGGER THOUGH HAVE KEPT CONVECTION LIMITED IN COVERAGE. MAIN ACTIVITY EARLIER WAS ALONG SEA BREEZE BOUNDARY...AND WERE PULSE VARIETY WITH WEAK WINDS ALOFT. ANY CONVECTION WILL WIND DOWN THIS EVENING AS BOUNDARY LAYER COOLS AND SFC BASED INSTABILITY DECREASES. THE CWA HAS BEEN IN THIS WARM/MUGGY AIRMASS...AND TEMPS WILL DROP SLOWLY TONIGHT...WITH MANY LOCATIONS REMAINING IN THE 70S PER MOS. MID TO UPPER 60S ACROSS THE INTERIOR. DO EXPECT PATCHY FOG AS LIGHT SOUTHERLY WINDS PERSIST AND TEMP/DEW POINT DEPRESSIONS SHRINK. THERE IS MODERATE RISK OF RIP CURRENTS INTO THIS EVENING AT THE OCEAN BEACHES. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... LARGE RIDGE OVER THE WESTERN ATLANTIC AND UP THE EASTERN SEABOARD PREVAILS THIS TIME FRAME. WITH THIS RIDGE IN PLACE...LIGHT WINDS AND PLENTY OF WARM AIR ALOFT SHOULD KEEP ANY AFTERNOON/EVENING CONVECTION TO A MINIMUM. SLIGHTLY COOLER BOUNDARY LAYER WILL RESULT IN LOWER SFC/MIXED LAYER INSTABILITY AS WELL. HOWEVER...ANY SHOWER OR THUNDERSTORM THAT DOES DEVELOP WILL PULSE BRIEFLY...AND COULD BE STRONG. THE COOLER BOUNDARY LAYER IS COURTESY OF INCREASING SOUTH TO SOUTHEAST FLOW...INJECTING MARINE LAYER OVER A GOOD PORTION OF THE CWA. HOWEVER TEMPS WILL STILL BE QUITE WARM TO HOT...80S TO NEAR 90. WITH HIGH DEW POINTS REMAINING IN THE 70S...HEAT INDICES WILL ONCE AGAIN RISE INTO THE 90S. A FEW LOCATIONS IN AND AROUND NYC COULD SEE 95 DEGREE HEAT INDICES...BUT GIVEN UNCERTAINTY AND MARGINAL CONDITIONS...WILL HOLD OFF ON ANY HEAT ADVISORIES AT THIS TIME. TIME OF YEAR A FACTOR WITH SEVERAL HEAT EVENTS UNDER OUR BELT AS WELL. ON SATURDAY NIGHT...MUGGY AND WARM CONDITIONS CONTINUE WITH SOUTH FLOW PERSISTING. STRATUS AND FOG EXPECTED ONCE AGAIN. FOLLOWED A MOS BLEND CLOSELY THROUGH THIS TIME PERIOD. HARD TO BEAT MOS NUMBERS IN THIS TYPE OF STAGNANT/PERSISTENT PATTERN. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HOT AND HUMID AIRMASS IN PLACE SUNDAY AS STRONG SOUTHERLY WINDS DEVELOP DUE TO A TIGHTENING PRESSURE GRADIENT BETWEEN HIGH PRES ANCHORED OVER THE WESTERN ATLANTIC AND AN APPROACHING COLD FRONT MOVING THROUGH THE OHIO VALLEY. CONDITIONS BECOME QUITE UNSTABLE AS TEMPS CLIMB THROUGH THE 80S...AROUND 90 IN/AROUND NYC...ALONG WITH SFC DEW POINTS WELL INTO THE 70S. THIS WILL RESULT IN A HEAT INDEX CLOSE TO 100 DEGREES IN/AROUND NYC AND THE URBANIZED AREAS OF NE NJ...AND IN THE LOW TO MID 90S ELSEWHERE. THERE MAY BE A FEW SHOWERS/TSTMS LINGERING INTO SUNDAY MORNING AS WEAK TROUGH/SHORTWAVE MOVE THROUGH THE REGION...BUT MORE ORGANIZED ACTIVITY WILL HOLD OFF UNTIL THE AFTERNOON AND EVENING HOURS AS THE COLD FRONT OVER THE OH VALLEY MOVES INTO WESTERN NY/PA DURING THE DAY SUNDAY. PRE-FRONTAL TROUGH AHEAD OF THE COLD FRONT WILL TRACK INTO WESTERN PORTIONS OF THE FORECAST AREA BY AFTERNOON...AND THAT LOOKS TO BE A TRIGGERING MECHANISM FOR SOME RATHER STRONG TO SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING. CAPE VALUES WILL BE OVER 2000 J/KG IN SOME PARTS OF NJ AND INTO NYC...ALONG WITH A LIFTED INDEX CLOSE TO -7 C AND INCREASING LOW LEVEL WINDS. AS THIS COMPLEX COLD FRONT/UPPER TROUGH/SHORTWAVE SYSTEM MOVES INTO THE AREA SUNDAY EVENING...SHOWERS AND THUNDERSTORMS WILL INCREASE IN INTENSITY AND COVERAGE SUNDAY EVENING. THUNDERSTORMS WILL BE CAPABLE OF DAMAGING WINDS IN THE AFTERNOON...BUT WITH LOSS OF DIURNAL HEATING COMES THE LOSS OF THE THREAT FOR DAMAGING WINDS. IN ADDITION TO THE DAMAGING WIND THREAT...THERE IS ALSO THE THREAT FOR URBAN/POOR DRAINAGE/SMALL STREAM FLOODING IN THE AFTERNOON/EVENING...THEN TORRENTIAL RAINFALL SUNDAY NIGHT WILL RESULT IN THE POTENTIAL FOR FLASH FLOODING OVERNIGHT SUNDAY NIGHT INTO MONDAY MORNING. WITH PWATS RANGING FROM 2.25-2.5 INCHES...THERE IS ABUNDANT MOISTURE IN THE ATMOSPHERE TO FEED ANY THUNDERSTORMS...AND TORRENTIAL RAINFALL IS EXPECTED. THINK THE MID LEVEL WINDS WILL BE TOO STRONG TO ALLOW ANY STORM TO LINGER OVER ANY ONE AREA...BUT TRAINING OF CELLS WILL LEAD TO FLASH FLOODING. PRECIPITATION TAPERS OFF FROM WEST TO EAST MONDAY MORNING AS THE FRONTAL SYSTEM TRACKS THROUGH THE REGION. THE FRONT BECOMES STATIONARY SOUTH OF LONG ISLAND LATE MONDAY THROUGH TUESDAY AS HIGH PRES BUILDS THROUGH THE REGION ON TUESDAY. HUMIDITY LEVELS WILL FALL DRASTICALLY AS DEW POINTS DROP FROM THE 70S INTO THE LOWER 60S. TUESDAY WILL END UP QUITE PLEASANT WITH LOW HUMIDITY...FAIR SKIES AND TEMPS IN THE 80S. STATIONARY FRONT SOUTH OF LONG ISLAND LIFTS BACK NORTH AS A WARM FRONT ON WEDNESDAY. ISOLATED SHOWERS/TSTMS POSSIBLE WITH ITS PASSAGE. SFC COLD FRONT WITH UPPER LEVEL SUPPORT FROM AN H5 TROUGH/SHORTWAVE COMBO THEN APPROACHES ON THURSDAY...POSSIBLY TOUCHING OFF SOME MORE SHOWERS/TSTMS. SOME CONCERNS WITH FORECAST LATE IN THE WEEK...AS HIGH PRES MOVES THROUGH THE REGION...BUT DEPENDING ON HOW FAST IT DEPARTS WILL IMPACT IF LOW PRES UPSTREAM MAKES IT TO THE LOCAL AREA OR NOT. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD WITH MAINLY VFR EXPECTED. THE ONLY EXCEPTION WILL BE SOME EARLY MORNING MVFR OR IFR FOG. ANY SUB-VFR CIGS ARE EXPECTED TO IMPROVE TO VFR BY 13Z-15Z SAT. ANY SHOWER OR THUNDERSTORM THAT DEVELOPS WILL BE ISOLATED AND TEMPORARY. PROBABILITY IS TOO LOW TO INCLUDE IN TAFS. WINDS ARE GENERALLY SW UNDER 10 KT THROUGH THE PERIOD. DURING SAT AFTERNOON...SEA BREEZES ARE EXPECTED TO SHIFT WINDS MORE SOUTHERLY AND INCREASE SLIGHTLY. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: FORECAST ON TRACK. NO UNSCHEDULED AMENDMENTS ANTICIPATED. KLGA FCSTER COMMENTS: FORECAST ON TRACK. NO UNSCHEDULED AMENDMENTS ANTICIPATED. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFTS. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFTS. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFTS. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFTS. ALSO NEARBY ISOLATED SHOWERS MAY REQUIRE AMENDMENTS IF THEY PASS NEAR THE AIRPORT. OUTLOOK FOR 18Z SAT THROUGH WED... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS....MAINLY IN THE AFTERNOON. LATE DAY TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE/WED...VFR. && .MARINE... PERSISTENT SOUTHERLY FLOW CONTINUES TONIGHT THROUGH SATURDAY. SUB SCA CONDITIONS ARE ANTICIPATED. FOLLOWED WAVE WATCH III OCEAN FORECASTS CLOSELY. SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKE UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING THROUGH SATURDAY. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH THE THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MPS/PW |
| #531545 (Received by flhurricane at: 3:29 PM 03.Aug.2012) AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 322 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL CROSS THE GREAT LAKES SUNDAY...BEFORE MOVING THROUGH SUNDAY NIGHT. WEAK HIGH PRESSURE WILL MOVE OVER THE MID-ATLANTIC REGION FOR THE FIRST PART OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... ISOLD TSTMS HV ALREADY DVLPD OVR THE MTNS. SUSPECT THIS WL CONT TO BE THE TREND THRU THE RMDR OF THE AFTN. 12Z IAD SNDG HAD A LGT WIND FIELD...AND MDL SNDG PROFILES WEREN`T STRONG EITHER...WHICH IS TYPICALLY THE CASE IN EARLY AUG GIVEN RGN IS USUALLY UNDER A BERMUDA HIGH W/ THE JET STREAM N OF THE BORDER. MUCH OF THE HZ THAT EXISTED THIS MRNG HAS LIFTED INTO CU THIS AFTN. IT IS PSBL THAT ANYWHERE IN THE FCST AREA COULD SEE AN ISOLD TSTM THRU MID EVE. ONCE AGN "SULTRY" MIGHT BE THE BEST WORD TO DESCRIBE THE OVRNGT HRS...AS THESE WL BE IN 80S THRU MDNGT E OF THE BLUE RDG W/ DWPTS IN THE U60S/L70S. OVRNGT LOWS WL RANGE FM THE L60S IN THE HIGHLANDS TO THE MU70S IN THE CITIES. MAJORITY OF CWA WL DROP TO THE U60S/L70S. TMRW WL BE A TYPICAL ERLY AUG DAY..IN FACT QUITE A BIT LK TDA. LGT FOG WL BECOME HZ...HZ WL BECOME AFTN CU. ONCE AGN THE MTNS WL BE THE BEST PLACE FOR AFTN CNVCTN TO FORM. HIGH TEMPS AGN XPCTD TO RANGE FM THE U80S TO THE M90S. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... DIURNAL CONVECTION ON SAT WILL WANE DURING THE EVE WITH THE LOSS OF DAYTIME HEATING. SAT NGT WILL BE MUGGY...WITH MIN TEMPS RANGING FROM THE MID 60S IN THE HIGHLANDS TO MID 70S ALONG AND EAST OF I-95. SHORTWAVE TROUGH OVER THE UPPER MIDWEST ERY SUN IS FCST TO LIFT NEWD ACROSS THE GREAT LAKES DURING THE DAY. THIS SHORTWAVE ENERGY WILL BE WEAKENING DURING THIS TIME AS THE UPPER-JET STREAK AHEAD OF THE TROUGH LIFTS NEWD INTO ERN CANADA. THE MID- ATLANTIC REGION WILL BE SITUATED IN THE PRE- FRONTAL WARM- MOIST SECTOR ON SUN AS A SFC COLD FRONT MOVES INTO THE OH VLY. AFTN TEMPS IN THE LOWER 90S AND DEWPOINTS IN LOWER 70S ON SUN WILL YIELD A MODERATE AMT OF INSTABILITY...AROUND 1.5-2 KJ/KG...BY THE AFTN. COVERAGE AND ORGANIZATION OF CONVECTION SHOULD BE BETTER NORTH AND WEST OF THE REGION...WHERE THE BEST SYNOPTIC LIFT ASSOCIATED WITH THE TROUGH/COLD FRONT RESIDE. GIVEN THE STEEP LLVL LAPSE RATES AND APPROACH OF A 30-KT LLVL JET BY EVE...A FEW STORMS MAY BECOME SEVERE DURING THE PEAK HEATING HRS. COLD FRONT WILL MOVE THRU SUN NGT. IF FRONT MOVES THRU EARLIER THAN 12Z MODELS INDICATE...THEN ORGANIZED CONVECTION AND A DAMAGING WIND THREAT MAY EXTEND EWD TOWARD THE WRN TERRAIN AND NRN MD DURING THE EVE. HOWEVER...ATMOSPHERE WILL BE LESS CONDUCIVE FOR SEVERE WEATHER FARTHER SOUTH AND EAST WHEN FRONT MOVES THRU SEVERAL HRS AFTER SUNSET. && .LONG TERM /MONDAY THROUGH FRIDAY/... AN UPPER-LEVEL TROUGH MOVES OVER THE REGION NEXT WEEK WITH NEAR TO SLIGHTLY ABOVE NORMAL TEMPS EXPECTED FOR EARLY AUGUST. THE SURFACE COLD FRONT THAT IS EXPECTED TO MOVE THROUGH THE REGION MONDAY SHOULD STALL TO THE SOUTH AS A BERMUDA HIGH PERSISTS IN THE ATLANTIC. LIFT ASSOCIATED WITH THE FRONT MAY PRODUCE SHOWERS AND THUNDERSTORMS BUT ACTIVITY SHOULD TO THE SOUTH THROUGH THE PERIOD. GFS AND ECMWF BRING FRONT NORTHWARD ON WEDNESDAY WHICH MAY PRODUCE SHOWERS AND THUNDERSTORMS ESPECIALLY FOR THE SOUTHERN HALF OF THE CWA. TROUGH WILL EVENUTALLY FLATTEN AND MOVE EASTWARD TOWARD THE END OF NEXT WEEK BEFORE THE NEXT WAVE ARRIVES NEXT FRIDAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR CONDS XPCTD THIS EVE. ISOLD TSTMS PSBL THRU MDNGT. LGT HZ/FG XPCTD AT IAD/CHO/MRB DURG THE OVRNGT HRS. ISOLD TSTMS PSBL AGN SAT AFTN. A COLD FRONT WILL APPROACH FROM THE NW SUN. SCT STORMS AHEAD OF THE FRONT SUN AFTN WILL INCREASE IN COVERAGE LATE IN THE DAY AND AT NGT AS THE COLD FRONT MOVES THRU. TEMPORARY RESTRICTIONS EXPECTED IN STORMS. VSBY RESTRICTIONS POSSIBLE IN FOG LATE SUN NGT...ESPECIALLY AT TERMINALS THAT WERE IMPACTED BY EARLIER STORMS. AS FRONT LINGERS TO THE SOUTH...VFR CONDITION EXPECTED MOST OF THE TIME. SHOWERS AND THUNDERSTORMS MAY CAUSE BRIEF PERIODS OF REDUCED VISBYS MAINLY FOR CHO TOWARDS THE END OF NEXT WEEK. LIGHT S-SW FLOW EXPECTED THROUGH THE PERIOD. && .MARINE... ISOLD GUSTS INTO THE SCA RANGE ARE PSBL IN THE WIDEST PART OF THE CHES BAY DURG THE RMDR OF THE AFTN. A STMT WL BE ISSUED TO ADDRESS THIS. WINDS ARE XPCTD TO RMN BLO SCA VALUES TNGT. MARGINAL SCA VALUES MAY BE PSBL SAT AFTN BUT WL REFRAIN FM ISSUANCE UNTIL EVENT DRAWS CLOSER. SCA HAS BEEN ISSUED FOR SAT NGT FOR THE MOUTH OF THE TIDAL POTOMAC RVR AND SRN ZONES OF THE MD CHSPK BAY...WHERE SLY CHANNELING WILL PRODUCE 20-KT GUSTS. SCA CONDITIONS POSSIBLE FOR MOST MARINE ZONES AS SLY WINDS INCREASE AHEAD OF A COLD FRONT. A FEW STORMS AHEAD OF THE FRONT COULD PRODUCE GUSTY WINDS LATE SUN. AS FRONT LINGERS SOUTH OF THE WATERS NEXT WEEK...LIGHT SOUTHWESTERLY FLOW EXPECTED. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ PRODUCTS...WOODY!/KLEIN/HAS |
| #531544 (Received by flhurricane at: 3:29 PM 03.Aug.2012) AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 317 PM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR SATURDAY INTO SUNDAY. && .NEAR TERM /THROUGH SATURDAY/... CHALLENGES WILL CONVECTION THIS AFTERNOON INTO THE EVENING AND HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE. TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL. HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY. AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL BE LAST TO CLEAR DURING THE AFTERNOON. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT. DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE LONG TERM PERIOD. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE VFR. SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART. HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5 FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3 FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW. SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY DROPPING THEM BACK 1-2 FEET. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT |
| #531541 (Received by flhurricane at: 3:29 PM 03.Aug.2012) AFDMLB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 315 PM EDT FRI AUG 3 2012 .DISCUSSION... ...TROPICAL MOISTURE TO MOVE OVER THE AREA THIS WEEKEND... ...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE... CURRENT...CONVECTIVE ACTIVITY CONTINUES MAINLY OVER THE INTERIOR AND OUR SRN ATLANTIC WATERS ASSOCIATED WITH THE UPPER LOW OVER CENTRAL FLORIDA AND TROPICAL WAVE ACROSS THE BAHAMAS. ACTIVITY OVER THE INTERIOR SHOULD CONTINUE TO TRANSLATE SLOWLY INLAND WITH ADDITIONAL CONVECTION DEVELOPING OVER THE KISSIMMEE RIVER BASIN AND LAKE COUNTY INTO LATE AFTERNOON. COLD MID LVL TEMPS WILL LEAD TO EFFICIENT LIGHTNING PRODUCING STORMS WITH ALSO THE THREAT OF LOCALLY HEAVY RAIN...SMALL HAIL AND GUSTY WINDS TO 45 MPH. FOR TONIGHT WILL CONTINUE POPS ACROSS THE INTERIOR INTO EARLY EVENING WITH A CHANCE OF SHOWERS AND STORMS MOVING ONSHORE ALONG THE COASTAL COUNTIES OVERNIGHT AS THE TROPICAL WAVE AXIS DRAWS CLOSER TO THE FLORIDA EAST COAST. SATURDAY..GFS INDICATES UPPER LOW WILL SLIDE INTO THE SE GULF OF MEXICO WITH THE TROPICAL WAVE MOVING AXIS MOVING ONSHORE. DEEP TROPICAL MOISTURE ASSOCIATED WITH THE WAVE AND UPPER LVL DIVERGENCE OVER THE AREA WILL PROMOTE A HIGH COVERAGE OF SHOWERS AND STORMS MOVING ONSHORE FLOW FROM THE ATLC IN STRENGTHENING LOW LVL SE FLOW. WILL INCREASE POPS TO 60-70 PCT RANGE WITH LOCALLY HEAVY RAINFALL OF AMOUNTS OF 2-3 INCHES POSSIBLE OVER PORTIONS OF THE AREA ESPEC ALONG THE COASTAL SECTIONS SOUTH OF THE CAPE. HIGHS WILL BE HELD DOWN SOME BY CLOUD COVER IN THE UPPER 80S AND LOWER 90S. SAT NIGHT...INCREASING LOW LVL SE FLOW AND T-WAVE AXIS OVER THE AREA WILL CONTINUE SHOWER AND TSTM CHANCES THROUGH THE NIGHT WITH HIGHER POPS ALONG THE EAST COAST. SOME LOCALLY HEAVY RAIN MAY OCCUR OVERNIGHT NEAR THE COAST. SUNDAY...EXPECT DEEP TROPICAL MOISTURE TO REMAIN OVER THE AREA WITH LOW LVL SE FLOW AS TROPICAL WAVES MOVES TOWARD THE EASTERN GULF. WILL EXPAND LIKELY POPS TO ALL OF EAST CENTRAL FLORIDA WITH SHOWERS AND STORMS CONTINUING TO MOVE ONSHORE. ADDITIONAL LOCALLY HEAVY RAINFALL AMOUNTS WILL BE POSSIBLE WITH RAIN CHANCES AROUND 60 PERCENT. PREVIOUS EXTENDED DISCUSSION....MON-FRI...BEHIND THE WEAK WAVE... FAIRLY DECENT STRENGTH DEEP LAYER MEAN RIDGING WILL BUILD BACK WWD FROM THE ATLC INTO FL. THE DEEP LAYER EASTERLIES SHOULD KEEP T.C. "ERNESTO" WILL SOUTH OF FL AS IT TRAVERSES WWD THROUGH THE CARIBBEAN. RELATIVELY DRIER EASTERLY FLOW WILL SPELL LOWER POPS...AS HIGHER RAIN CHANCES SHIFT TO THE WRN SIDE OF THE PENINSULA. RAN WITH POP NUMBERS NEAR NORMAL MON-TUE...THEN A LITTLE BELOW NORMAL FOR EARLY AUGUST FROM MID WEEK ONWARD. MAX TEMPS NEAR CLIMO WITH MINS A LITTLE ABOVE OWING TO LIGHT NOCTURNAL ONSHORE WINDS. && .AVIATION...SCT TSRA WILL AFFECT NRN TERMINALS THROUGH LATE AFTERNOON WITH TEMPO MVFR CIGS/VSBYS. ATLC SHRA/TSRA WILL APPROACH THE COAST LATE TONIGHT AND MAY AFFECT CSTL TERMINALS FROM KMLB-KSUA AFT 06Z INTO SATURDAY MORNING. && .MARINE...SE WINDS EXPECTED AT 10-15 KNOTS TONIGHT AND THEN INCREASING TO 15-20 KNOTS ACROSS THE OFFSHORE WATERS ON SATURDAY ASSOCIATED WITH TROPICAL WAVE. THE INCREASING SE FLOW WILL BUILD SEAS TO AROUND 5 FT OFFSHORE AND SMALL CRAFT EXERCISE CAUTION STATEMENTS MAY BE REQUIRED FOR THE WEEKEND. SCATTERED TO NUMEROUS SHOWERS AND STORMS WILL ALSO AFFECT THE WATERS SAT INTO SUNDAY AS THE TROPICAL WAVE MOVES ACROSS FL. SE WINDS WILL CONTINUE INTO MID WEEK WITH SOME LOWERING MOISTURE LEVELS DECREASING SHOWER AND TSTM COVERAGE TOWARD MID WEEK. && .PRELIMINARY POINT TEMPS/POPS... DAB 76 90 77 90 / 30 60 30 60 MCO 75 92 76 91 / 30 60 30 60 MLB 78 89 77 89 / 30 70 40 60 VRB 77 90 76 90 / 30 70 40 60 LEE 76 92 77 91 / 30 60 30 60 SFB 76 92 76 91 / 30 60 30 60 ORL 76 92 77 91 / 30 60 30 60 FPR 77 89 77 89 / 30 70 40 60 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ |
| #531540 (Received by flhurricane at: 3:17 PM 03.Aug.2012) AFDMOB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 1245 PM CDT FRI AUG 3 2012 .AVIATION UPDATE (18Z ISSUANCE)...SCATTERED TSRA WILL CONTINUE TO INCREASE AROUND THE TERMINALS THROUGH THE AFTERNOON. THE CONVECTION WILL DISSIPATE THIS EVENING FOLLOWED BY MORE DEVELOPMENT SATURDAY MORNING. /13 *************************PREVIOUS***************************** .SHORT TERM [TODAY AND TONIGHT]...CONTINUE TO SEE VERY LITTLE CHANGE IN THE LARGE SCALE PATTERN WITH AMPLIFIED MID LEVEL RIDGE HOLDING STRONG OVER TEXAS AND A TROF FROM THE MID ATLANTIC SOUTHWARD ACROSS FLORIDA. SURFACE ANALYSIS SHOWS A STALLED FRONTAL ZONE DRAPED FROM THE OHIO RIVER VALLEY BACK ACROSS OKLAHOMA/NORTH TEXAS. WATER VAPOR IMAGERY SHOWS A WELL DEFINED RING OF MOISTURE AROUND THE TEXAS HIGH LEVEL RIDGE...WHERE FORECASTERS HAVE SEEN QUITE A BIT OF LIGHTNING ACTIVITY FROM WESTERN MEXICO UP THROUGH THE CENTRAL PLAINS AND DOWN INTO THE SOUTHEAST FROM THE PAST AFTERNOON. THE MOISTURE PATTERN HOLDS WITH BUFR FORECAST SOUNDINGS SHOWING PRECIPITABLE WATER VALUES AROUND 2 INCHES. CONSIDERING THIS LONG WITH ENVIRONMENTAL INSTABILITY AND MID LEVEL IMPULSES THAT MOVE OUT OF THE MID SOUTH...SINKING SOUTHWARD ACROSS THE FORECAST AREA....FORECASTERS EXPECT ANOTHER ROUND OF SCATTERED SHOWERS/STORMS TO FORM DURING THE DAY. THERE IS A DIFFERENCE OF OPINION BETWEEN THE NAM/GFS ON DEGREE OF INSTABILITY WITH THE GFS HIGHEST...SHOWING MOST UNSTABLE ENVIRONMENTAL VALUES BETWEEN 3000 AND 4000 J/KG. GIVEN LITTLE TO NO CHANGE IN PATTERN...THE GFS OUTPUT SEEMS MORE PLAUSIBLE. TAKING A LOOK AT THE HIGHER RESOLUTION WRF...CONVECTIVE INITIATION LOOKS TO BEGIN ALONG THE COAST BY AND AFTER 11 AM. THE HRRR ALSO SUPPORTS THIS. AS HAS BEEN THE CASE FOR THE PAST SEVERAL DAYS...STORMS CAN BE STRONG AND CAPABLE OF FREQUENT...POTENTIALLY DEADLY LIGHTNING...STRONG WIND GUSTS FROM 45 TO 55 MPH...LOCALLY HEAVY RAINS AND SMALL HAIL. A FEW COULD ALSO INTENSIFY BRIEFLY TO SEVERE LEVELS WITH DAMAGING WINDS IN EXCESS OF 60 MPH AND HAIL TO AROUND QUARTER SIZE. STORM MOTION IS FORECAST TO BE GENERALLY SOUTHWARD AT 15 TO 20 MPH. BEFORE THE ONSET OF STORMS...HIGHS TODAY FORECAST INTO THE MID 90S OVER THE INTERIOR AND CLOSER TO 90 ALONG THE COAST. TONIGHT`S LOWS IN THE LOWER/MID 70S. /10 THE WET MICROBURST RISK FOR TODAY IS HIGH. [THIS WEEKEND]...WE WILL START OFF THE UPCOMING WEEKEND WITH AN AREA OF UPPER WEAKNESS OVER THE EASTERN HALF OF THE FORECAST AREA SITUATED BETWEEN TWO LARGE UPPER HIGHS...ONE OVER THE SOUTHERN PLAINS AND ONE OVER THE WESTERN ATLANTIC. THIS UPPER WEAKNESS...IN THE FORM OF AN INVERTED TROUGH...WILL CREEP SLOWLY WESTWARD THROUGH MONDAY MORNING AS AN UPPER TROUGH MOVES ACROSS THE NORTHEAST CONUS AND THE SOUTHERN PLAINS HIGH RETROGRADES TOWARD THE WEST. WE WILL CONTINUE TO SEE SEVERAL DISTURBANCES ROUNDING THE EASTERN PERIPHERY OF THE SOUTHERN PLAINS UPPER HIGH...AND APPROACH THE FORECAST AREA FROM THE NORTH...RESULTING IN A MAINLY DIURNAL PATTERN OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE WEEKEND. THE ENVIRONMENT WILL ALSO REMAIN FAVORABLE FOR STRONG TO POSSIBLY SEVERE CONVECTION BOTH AFTERNOONS AS MLCAPES APPROACH 2000 TO 2500 J/KG ACROSS THE ENTIRE FORECAST AREA. MAIN THREATS WILL MAINLY BE STRONG WET MICROBURST WINDS...LIGHTNING...AND PROLONGED PERIODS OF HEAVY RAIN AND LOCALIZED FLOODING DUE TO A SLOWER AND ERRATIC MOVEMENT OF THE STORMS. HIGH TEMPERATURES BOTH DAYS WILL REMAIN NEAR NORMAL...RANGING FROM 87 TO 92 DEGREES. HIGHEST AFTERNOON HEAT INDICES WILL RANGE FROM 96 TO 101 DEGREES. LOWS BOTH NIGHTS WILL BE IN THE LOWER TO MID 70S INLAND AREAS...WITH UPPER 70S ALONG THE BEACHES. AS FOR TROPICAL STORM ERNESTO...THE OFFICIAL FORECAST DOES HAVE THE SYSTEM MOVING ACROSS THE CARIBBEAN SEA OVER THE WEEKEND...AND STRENGTHENING INTO A HURRICANE SOUTH OF JAMAICA BY MIDNIGHT SUNDAY NIGHT. THE EXPECTED INCREASE IN INTENSITY OF ERNESTO IS ATTRIBUTED TO THE SYSTEM MOVING INTO AN AREA OF VERY LOW WIND SHEAR AND OVER SEA SURFACE TEMPERATURES NEAR 83 DEGREES. /22 && .LONG TERM [MONDAY THROUGH THURSDAY]...ERNESTO IS FORECAST TO CONTINUE ON ITS WESTWARD TRACK AS A HURRICANE THROUGH EARLY NEXT WEEK...REACHING NEAR THE TIP THE YUCATAN PENINSULA TUESDAY NIGHT. IN THE MEANTIME...THE UPPER WEAKNESS WILL REMAIN OVER THE FORECAST AREA THROUGHOUT THE LONG TERM. TYPICAL MID SUMMER CONVECTION WILL PERSIST THROUGH THE LONG TERM...WITH MAINLY DIURNAL DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS FORECAST EACH DAY AS NUMEROUS DISTURBANCES CONTINUE TO MOVE OVER THE FORECAST AREA. HIGH TEMPERATURES EACH DAY WILL REMAIN NEAR OR SLIGHTLY ABOVE NORMAL RANGING FROM 90 TO 95 DEGREES. HIGHEST AFTERNOON HEAT INDICES EACH AFTERNOON WILL CONTINUE TO RANGE FROM 96 TO 101 DEGREES. LOWS EACH NIGHT THROUGH THE ENTIRE LONG TERM WILL BE IN THE LOWER TO MID 70S INLAND AREAS...WITH UPPER 70S ALONG THE BEACHES. /22 && .AVIATION [03.12Z KMOB/KBFM/KPNS TAF ISSUANCES]...EXPECT OCCASIONAL IFR CONDITIONS DUE TO CIGS/VSBYS IN SCATTERED TSRA MAINLY AFTER 16Z. ALTHOUGH TSRA WILL BE FORMING OVER LAND WHILE MOVING SOUTH DURING THE LATE MORNING AND EARLY AFTERNOON HOURS...THE ENHANCEMENT OF TSRA ALONG THE COAST DUE TO THE SEABREEZE WILL PROVIDE SLIGHTLY MORE COVERAGE ACROSS COASTAL TERMINALS. /10 && .MARINE...A BROAD RIDGE OF SURFACE HIGH PRESSURE OVER THE SOUTHWEST ATLANTIC NOSES WESTWARD INTO THE GULF THROUGH THE EARLY HALF OF NEXT WEEK. THIS WILL MAINTAIN A GENERAL LIGHT ONSHORE FLOW WITH SIGNIFICANT WAVE HEIGHTS 2 FEET OR LESS. WINDS...WAVES AND SEAS LOCALLY HIGHER NEAR STORMS. /10 && .FIRE...SURFACE HIGH PRESSURE WILL REMAIN OVER THE GULF THROUGH THE WEEKEND WITH A LIGHT SOUTH TO SOUTHWESTERLY FLOW EXPECTED. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE FORECAST MAINLY DURING THE AFTERNOONS THROUGH THE WEEKEND AS WELL. DISPERSIONS WILL BE FAIR TO GOOD IN THE AFTERNOON PRIMARILY DUE TO HOT TEMPERATURES AND DEEP MIXING HEIGHTS. FOG POTENTIAL AND OTHER REMARKS...LIGHT PATCHY FOG IS POSSIBLE DURING THE EARLY MORNING HOURS...BUT IS NOT FORECAST TO BE A WIDESPREAD CONCERN. /22 && .PRELIMINARY POINT TEMPS/POPS... MOBILE 92 76 88 74 / 50 20 60 30 PENSACOLA 90 75 88 76 / 50 20 50 30 DESTIN 90 77 87 77 / 40 20 40 30 EVERGREEN 94 73 87 72 / 50 30 60 30 WAYNESBORO 94 74 90 73 / 50 20 60 30 CAMDEN 94 75 89 73 / 50 30 60 30 CRESTVIEW 93 73 87 71 / 50 20 60 30 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$ |
| #531539 (Received by flhurricane at: 3:17 PM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 315 PM EDT FRI AUG 3 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL STALL OVER THE REGION TONIGHT... BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HOT AND HUMID CONDITIONS WILL CONTINUE TOMORROW AND SUNDAY. A STRONGER COLD FRONT WILL CROSS THE REGION LATE SUNDAY NIGHT OR MONDAY BRINGING ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE AREA. HIGH PRESSURE BUILDS OVER THE REGION MONDAY THROUGH WEDNESDAY WITH DRIER CONDITIONS EXPECTED. && .NEAR TERM /TONIGHT/... WEAK FRONTAL BOUNDARY APPROACHING THE AREA THIS AFTERNOON FROM THE NORTHWEST. VISIBLE SATELLITE IMAGERY SHOWS DECENT CLEARING ACROSS MOST OF THE FORECAST AREA. MODIFIED 12Z KGYX SOUNDING INDICATES UPWARDS OF 2500J/KG WORTH OF CAPE TO WORK WITH. ALTHOUGH SHEAR IS WEAK...EXPECT SOME SCATTERED STORMS TO DEVELOP THIS AFTERNOON AND EVENING. SOME MAY BE STRONG ENOUGH TO REACH SEVERE LIMITS...BUT THEY SHOULD BE PRETTY ISOLATED. ONCE DIURNAL HEATING FADES CONVECTION SHOULD DIE OFF PRETTY QUICKLY. WITH DEWPOINTS STILL WELL INTO THE 60S...EXPECT FOG TO SET UP AGAIN ACROSS MUCH OF THE AREA. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... FOG AND STRATUS SHOULD BURN OFF DURING THE MORNING HOURS TOMORROW. FRONTAL BOUNDARY STALLED TO OUR SOUTH WILL START TO MAKE ITS WAY NORTHWARD AS A WEAK WARM FRONT. NOT MUCH LEFT IN THE WAY OF DYNAMICS WITH THE BOUNDARY AND SHOWERS AND THUNDERSTORMS MAY BE LIMITED TO WESTERN PORTIONS OF CWA AND THE MOUNTAINS. EXPECT CLEARING GOING INTO SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... SOUTHERLY FLOW TRANSPORTS MORE MOISTURE INTO THE REGION ON SUNDAY IN ADVANCE OF AN APPROACHING TROUGH. WILL PROBABLY SEE FOG ALONG THE COAST WHICH MAY LAST INTO THE AFTERNOON ESPECIALLY ON THE MIDCOAST. OUTSIDE OF FOGGY AREAS... TEMPERATURES WILL WARM WELL INTO THE 80S. TIMING OF THE TROUGH AND ASSOCIATED COLD FRONT SEEM TO SUGGEST THAT PRECIPITATION WILL BE LATER IN ARRIVING. SHOULD SEE A CHANCE OF SHOWERS AND THUNDERSTORMS LATE SUNDAY AFTERNOON AND THROUGH SUNDAY NIGHT. THIS TIMING MEANS THE SEVERE WEATHER THREAT WILL BE MINIMIZED. HOWEVER... EVEN WITH THE PASSAGE DURING THE NIGHTTIME HOURS IN THE ABSENCE OF SURFACE BASED INSTABILITY... INSTABILITY ALOFT GENERATED BY THE TROUGH AND COLD ADVECTION ALOFT MAY BE ENOUGH TO KEEP THUNDERSTORMS GOING. SHEAR WOULD BE SUFFICIENT FOR SUPERCELLS AND BOWING MULTICELL STORMS GIVEN ENOUGH INSTABILITY. COLD FRONT MAKES A FULL PASSAGE THROUGH THE AREA BY MONDAY MORNING OR EARLY MONDAY AFTERNOON. MAY STILL SEE SOME SHOWERS AND STORMS LINGERING AHEAD OF THE FRONT THROUGH EARLY MONDAY. OTHERWISE WILL SEE A CLEARING AND DRYING TREND AS HIGH PRESSURE BUILDS IN FROM THE WEST. HIGH PRESSURE GENERALLY HOLDS THROUGH TUESDAY... ALTHOUGH A WEAK SHORTWAVE TROUGH CROSSES JUST NORTH OF THE INTERNATIONAL BORDER. ANOTHER SHORTWAVE TROUGH DIGS FURTHER SOUTH ON WEDNESDAY AND THURSDAY... WITH SHOWERS AND THUNDERSTORMS POSSIBLE PRIMARILY DURING THE AFTERNOON EACH DAY OVER INTERIOR LOCATIONS. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM...EXPECT VFR CONDITIONS TO DETERIORATE TONIGHT TO IFR/LIFR CONDITIONS IN FOG. FOG WILL LIFT BY MID-MORNING TOMORROW WITH VFR CONDITIONS RETURNING AND REMAINING IN PLACE FOR THE REMAINDER OF THE SHORT TERM PERIOD. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...WILL PROBABLY SEE FOG RETURN SATURDAY NIGHT INTO EARLY SUNDAY ALONG THE COAST. FOG WILL LINGER LONGEST ALONG THE MIDCOAST NEAR ROCKLAND AND MAY EVEN LAST THROUGH THE AFTERNOON. EXPECT SHOWERS AND THUNDERSTORMS LATE SUNDAY THROUGH EARLY MONDAY. GENERALLY VFR AFTER THE COLD FRONT MOVES THROUGH ON MONDAY THROUGH THE MIDDLE OF THE WEEK. && .MARINE... SHORT TERM /THROUGH SATURDAY...A WEAK FRONT DROPS INTO THE GULF OF MAINE ON FRIDAY BEFORE DISSIPATING. WINDS AND SEAS SHOULD REMAIN FAIRLY QUIET. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...SOUTHERLY FLOW WILL INCREASE IN ADVANCE OF AN APPROACHING COLD FRONT ON SUNDAY. ALTHOUGH WINDS MAY STAY BELOW 25 KT... SEAS WILL GRADUALLY BUILD ON THE SOUTHERLY FETCH AND WAVE HEIGHTS MAY EXCEED 5 FEET. THE COLD FRONT WILL CROSS THE WATERS ON MONDAY WITH A RETURN TO MORE TRANQUIL CONDITIONS. && .CLIMATE... THE MONTHLY CLIMATE SUMMARIES FOR JULY FOR PORTLAND, CONCORD AND GRAY WERE ISSUED THIS AFTERNOON. THEY ARE UNDER THE AWIPS IDENTIFIERS PWMCLMPWM, PWMCLMCON AND PWMCLMGYX RESPECTIVELY. THEY ARE ALSO AVAILABLE ON OUR WEB SITE AT WWW.WEATHER.GOV && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ |
| #531538 (Received by flhurricane at: 3:17 PM 03.Aug.2012) AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 316 PM EDT Fri Aug 3 2012 .NEAR TERM [Through Tonight]... Typical sea breeze day across the region with convective outflows moving into South Georgia/Alabama as of 3 pm ET. Expect storms to continue to initiate along and ahead of this boundary through 8 pm ET before the atmosphere slowly stabilizes with the loss of daytime heating. With the weak steering flow aloft, more organized convective complex across West Central Alabama is not anticipated to affect the area overnight. With light winds and a very moist surface airmass in place, included mention of patchy fog in the forecast overnight. It would not be surprising to see a repeat of the last couple of nights with areas of dense fog developing before sunrise, but the exact placement of any dense fog remains uncertain at this time. && .SHORT TERM [Saturday Through Sunday Night]... The main feature of concern over the short-range period will be the tropical wave currently situated over the northern Bahamas. This feature is expected to move west across the FL Peninsula tonight into Saturday and then across the eastern Gulf of Mexico from Sunday into Monday. The NAM continues to want to develop a tropical cyclone as early as tonight. This is on the deep end of the spectrum of solutions as is still not accepted. We favor a solution similar to a GFS/ECMWF blend which maintains an open wave as the system crosses FL and the Gulf. For Saturday, we will not quite yet be feeling any impacts from the tropical wave. Instead, a short wave currently over the TN Valley will drop down the east side of the large Southern Plains ridge and enhance PoPs across our zones, particularly out west. Most of the area is getting a likely PoP. By Sunday, the wave will begin pulling in deep tropical moisture into the area from the southeast. Likely PoPs are forecast for the southeastern half of the forecast area. Temps will generally run a degree or two above normal. Eastern areas will be a couple of degrees cooler on Sunday due to abundant cloud cover and numerous showers. && .LONG TERM [Monday through Friday]... Weak tropical wave axis is forecast to pass across the forecast area late Sunday into Monday. With the southeasterly flow in the wake of the wave and a weakness aloft between subtropical ridges to the east and west, expect deep layer moisture to remain elevated on Monday with at least scattered showers and thunderstorms across the entire forecast area. The onshore low-level flow trajectory is expected to continue through at least Thursday, keeping PoPs elevated and temperatures near seasonal norms. && .AVIATION... [through 12Z Saturday] Tempos included at TLH/ECP through the mid afternoon hours with vicinity groups elsewhere to account for sea breeze convection. Thus far, storm coverage has been to scattered to include tempos further inland at ABY/DHN. Overnight...expect at least MVFR conditions to develop at all sites except ECP. IFR conditions are possible prior to sunrise, but confidence is too low to include in the forecast at this time. Any restrictions should end by 14z with thunderstorms on Saturday developing around 18z. && .MARINE... A ridge of high pressure south of the area is expected to shift north as a tropical wave over the Bahamas approaches from the east. This wave is expected to cross the FL Peninsula tonight into Saturday and then move westward across the eastern Gulf of Mexico from Sunday into Monday. This system will back winds to the east and possibly northeast from Saturday into Sunday night. At this point, the wave is not forecast to develop into a tropical cyclone and we keep winds 15 knots or less. However, interests in the eastern Gulf of Mexico should monitor the latest outlooks from the National Hurricane Center on this feature over the weekend. Once the wave moves away into the central gulf, the ridge will re-establish itself over the area swinging winds back to onshore. && .FIRE WEATHER... Afternoon Relative Humidity levels are expected to remain above critical thresholds for the next week, so red flag conditions are not expected. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 75 93 74 93 74 / 30 60 40 70 50 Panama City 77 91 75 92 77 / 30 40 20 50 40 Dothan 76 92 74 93 74 / 40 60 40 50 30 Albany 75 93 73 93 75 / 40 60 30 50 30 Valdosta 73 93 72 91 73 / 30 50 30 70 40 Cross City 72 94 72 91 74 / 20 50 40 70 50 Apalachicola 75 90 75 91 76 / 30 40 20 60 50 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ |
| #531535 (Received by flhurricane at: 3:11 PM 03.Aug.2012) AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 259 PM EDT FRI AUG 3 2012 .SHORT TERM...(TONIGHT-MONDAY) THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING NORTH- NORTHEAST JUST EAST OF SOUTH FLORIDA TO THE NW BAHAMAS WITH MOST OF THE SHOWER/TSTM COVERAGE REMAINING AROUND THE TROUGH AXIS...INCLUDING OUR ADJACENT ATLANTIC WATERS. THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS SURFACE TROUGH JUST EAST OF THE LOCAL AREA AND GENERALLY INDICATES IT CONTINUING WESTWARD OVER SOUTH FLORIDA THROUGH THE DAY SATURDAY...POSSIBLY AS A WEAK LOW. AS A RESULT...WE WILL ADJUST THE RAINFALL CHANCES UP THROUGH THIS PERIOD OVER THE WEEKEND FROM WHAT WAS ADVERTISED IN THE PREVIOUS PACKAGE. THE NAM SOLUTION REMAINS THE OUTLIER AND INDICATES THIS FEATURE DEVELOPING A WELL DEFINED LOW-LEVEL CIRCULATION CENTER AND ADVANCING NW AND MOVING ASHORE ALONG THE EAST-CENTRAL PORTION OF THE FLORIDA PENINSULA LATER SATURDAY NIGHT. FOR THIS PACKAGE...WE WILL REMAIN CLOSER TO THE LATEST GFS/ECMWF SOLUTIONS AND GENERALLY SHOW IT CONTINUING WEST ACROSS THE AREA OVER THE WEEKEND. SUNDAY THROUGH MONDAY...MOIST SOUTHEAST FLOW WILL BE EXPECTED AS THE AFOREMENTIONED SURFACE TROUGH/UPPER LOW CONTINUES WEST AND AWAY FROM THE FL PENINSULA AND ERNESTO CONTINUES ITS WESTWARD TRACK ACROSS THE CARIBBEAN. MODERATE EASTERLY FLOW DUE TO AN ENHANCED GRADIENT BETWEEN ERNESTO TO THE SOUTH AND THE SUBTROPICAL RIDGE TO THE NORTH COMBINED WITH PRECIPITABLE WATER VALUES AROUND THE TWO INCH MARK WILL KEEP THE RAIN CHANCES IN THE FORECAST THROUGH THE PERIOD. .LONG TERM...(MONDAY NIGHT-THURSDAY)... THE CHANCE OF RAIN TAPERS OFF FROM MIDWEEK ON AS THE ATLC HIGH CENTER MOVES WESTWARD PULLING SOME DRIER AIR OVER S FLA. A DEEP EASTERLY WIND FLOW DICTATES THAT THE HIGHER POPS WILL BE IN THE W INTERIOR AND W COAST. FORECASTED HURRICANE ERNESTO APPROACHES THE YUCATAN PENINSULA BY MID WEEK. AS ERNESTO TRACKS WESTWARD...AT THIS TIME...THE ONLY EFFECT TO S FLA WILL BE AN INCREASE IN THE LOW LEVEL EASTERLY WINDS FROM MIDWEEK ON. BUT KEEP AWARE OF NHC FORECASTS OF THE DEVELOPMENT AND FORECASTED MOVEMENT OF THIS STORM. && .MARINE... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE EXPECTED ACROSS THE ATLANTIC WATERS TONIGHT THROUGH SATURDAY AS A TROUGH OF LOW PRESSURE TRACKS WEST OVER THE AREA. WINDS AND SEAS WILL BE LOCALLY HIGHER IN AND AROUND THE HEAVIER SHOWERS AND STORMS THROUGH THIS TIME. EASTERLY WINDS ARE EXPECTED TO REACH THE MODERATE LEVELS INTO THE UPCOMING WEEK AS THIS TROUGH SHIFTS WEST OF THE MARINE AREAS AND TROPICAL STORM ERNESTO PASSES WELL SOUTH. && .FIRE WEATHER... NO CONCERNS THROUGH THE WEEKEND AND INTO THE UPCOMING WEEK AS PLENTY OF MOISTURE AND RAIN CHANCES REMAIN IN THE FORECAST. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 89 77 88 / 50 70 50 40 FORT LAUDERDALE 79 90 79 89 / 40 70 50 40 MIAMI 78 89 78 90 / 40 70 50 40 NAPLES 76 91 76 92 / 30 50 50 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ |
| #531534 (Received by flhurricane at: 3:02 PM 03.Aug.2012) AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 251 PM EDT FRI AUG 3 2012 .SHORT TERM /TONIGHT THROUGH SUNDAY/... SCATTERED SHOWERS AND TSTMS ARE DEVELOPING ALONG THE ATLANTIC SEABREEZE ACROSS NE FL...AND IN PROXIMITY OF A WEAK MID LEVEL TROUGH ACROSS SE GA. SMALL SCALE BOUNDARY COLLISIONS...ALONG WITH ABUNDANT MOISTURE/INSTABILITY WILL RESULT IN ADDITIONAL STORMS FIRING LATE THIS AFTERNOON INTO EARLY EVENING. WILL USE MID END SCATTERED POPS FOR THIS ACTIVITY. CONVECTION WILL DISSIPATE BY MIDNIGHT FOR MOST AREAS...WITH PERHAPS A COASTAL SHOWER OR TWO IN THE OVERNIGHT. A TROPICAL WAVE CURRENTLY JUST NORTH OF THE BAHAMAS WILL MOVE TO THE WEST-NORTHWEST THROUGH SATURDAY. SOME OF THE MOISTURE FROM THE WAVE WILL APPROACH THE AREA BY SATURDAY AFTERNOON. WITH THE WAVE STILL TO THE SOUTH OF THE AREA...WILL KEEP POPS SCATTERED FOR NOW...WITH THE GREATEST COVERAGE ALONG SOUTHERN PORTIONS OF THE NE FL COAST...AND INLAND ACROSS THE REST OF NE FL AND SE GA WITH SEABREEZE/SMALL SCALE BOUNDARY INTERACTIONS. SOME ADDITIONAL CLOUDS...HIGHER COVERAGE...AND ONSHORE FLOW WILL KEEP TEMPERATURES DOWN SLIGHTLY ALONG THE COAST...WITH NEAR NORMAL VALUES EXPECTED. ANOTHER HOT DAY IN STORE INLAND...WITH LOWER TO MID 90S. SATURDAY NIGHT AND SUNDAY...MODELS CONTINUE TO OFFER DIFFERING SOLUTIONS WITH REGARDS TO INTENSITY...TRACK AND TIMING OF THE TROPICAL WAVE MOVING OUT OF THE BAHAMAS. THE NAM BRINGS A WEAK BUT CLOSED LOW INTO CENTRAL FLORIDA SATURDAY NIGHT....AND WITH WIDESPREAD HEAVY RAINFALL POSSIBLE ON THE NORTHEAST SIDE OF THE LOW...THIS SOLUTION WOULD BE THE WETTEST SCENARIO FOR OUR AREA. THE UNWAVERING GFS INSISTS ON A MUCH FLATTER WAVE ACROSS SOUTHERN FLORIDA. REGARDLESS OF THE SOLUTION...ALL MODELS SHOW DEEP TROPICAL MOISTURE SPREADING NORTH ACROSS THE AREA. OUR LATEST FORECAST WILL CONTINUE TO SIDE MOSTLY WITH THE GFS WITH A SLIGHT NOD GIVEN TO THE HIGHER POPS OFFERED UP BY THE NAM. THE PRIMARY CHANGES TO THE FORECAST WAS TO INCREASE POPS A BIT ALONG THE COAST AND ACROSS THE SOUTH DURING THE PREDAWN HOURS EARLY SUNDAY MORNING. SKY GRIDS WERE ALSO INCREASED TO REFLECT AN INCREASE IN CLOUD COVER BROM SOUTHEAST TO NORTHWEST BEGINNING SATURDAY NIGHT. CURRENT THINKING IS THAT SUNDAY WILL BEGIN WITH SCATTERED TO NUMEROUS SHOWERS AND STORMS ALONG THE ATLANTIC COAST AND END WITH NUMEROUS TO PERHAPS WIDESPREAD COVERAGE OVER THE INTERIOR AND WESTERN PORTIONS OF NORTHEAST FLORIDA. MAX POPS WERE INCREASED TO 70 PERCENT ACROSS THE SOUTHWESTERN PORTIONS OF THE AREA SUNDAY AFTERNOON. MULTILAYER CLOUDS AND INCREASED COVERAGE OF PRECIP WILL TAME HIGHS A BIT AND HAVE LOWERED TEMPS A FEW DEGREES ON SUNDAY. IN FACT...MANY AREAS OF NORTHEAST FLORIDA WILL LIKELY STRUGGLE TO REACH 90. TROPICAL WAVE TO EXIT WEST INTO THE GULF BY SUNDAY NIGHT AND PRECIP SHOULD WANE FROM EAST TO WEST DURING THE AFTERNOON. && .LONG TERM...MONDAY THROUGH FRIDAY WE WILL TRANSITION BACK TO A MORE TYPICAL SEABREEZE DOMINATED DIURNAL THUNDERSTORM PATTERN ON MONDAY AND TUESDAY. WITH DEEP TROPICAL MOISTURE LINGERING OVER THE AREA...COVERAGE SHOULD BE AT LEAST SCATTERED ALONG THE MORE DOMINANT EAST COAST SEABREEZE EACH AFTERNOON ACROSS THE INTERIOR. TEMPERATURES WILL TOP OUT IN THE LOW 90S EACH DAY...RIGHT WHERE WE WOULD EXPECT TO BE THIS TIME OF YEAR. THE LATEST GFS SHOWS SOME DRIER AIR WORKING IN FROM THE EAST MID TO LATE NEXT WEEK AND THIS COULD CUT BACK ON AFTERNOON THUNDERSTORMS A BIT...ESPECIALLY ACROSS NORTHEAST FLORIDA. WILL RESIST LOWERING POPS UNTIL THIS BECOMES MORE CERTAIN. && .AVIATION... ATLANTIC SEABREEZE HAS ALREADY PUSHED INLAND PAST JAX...SO CRG AND SSI FOR THE MOST PART SHOULD BE IN THE CLEAR AS FAR AS CONVECTION IS CONCERNED THIS AFTERNOON. WILL CONTINUE WITH VCTS AT THE OTHER 3 TERMINALS...WITH GNV STANDING THE BEST CHANCE OF SEEING AN AMENDMENT TO ADD TSRA. ANY THUNDERSTORM WILL BE CAPABLE OF BRIEF IFR CONDITIONS IN HEAVY RAINFALL. OTHERWISE...VFR WILL PREVAIL THROUGH TOMORROW MORNING. && .MARINE... A RIDGE OF HIGH PRESSURE OVER THE REGION WILL CONTINUE TO LIFT NORTH OF THE WATERS THIS WEEKEND...WITH A TROPICAL WAVE CROSSING JUST TO THE SOUTH OF THE WATERS. S/SE FLOW WILL BACK TOWARDS THE E/SE SATURDAY INTO EARLY NEXT WEEK. EXPECT WIND SPEEDS TO REMAIN UNDER SCEC CRITERIA...10 TO 15 KNOTS. SHOWER/TSTM COVERAGE WILL INCREASE TO SCATTERED THIS WEEKEND AS THE WAVE MOVES OFF TO THE WEST. RIP CURRENTS: LOW RISK THROUGH SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 71 93 72 92 / 30 40 20 50 SSI 77 87 79 88 / 20 30 40 50 JAX 73 91 76 89 / 30 30 30 60 SGJ 75 89 79 87 / 20 30 40 60 GNV 70 92 73 89 / 30 40 30 70 OCF 71 92 74 89 / 30 40 30 70 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ |
| #531533 (Received by flhurricane at: 2:57 PM 03.Aug.2012) AFDBRO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 144 PM CDT FRI AUG 3 2012 .SHORT TERM.../THIS AFTERNOON THROUGH SATURDAY NIGHT/...STRONG MID AND UPPER RIDING PERSISTS OVER CENTRAL TEXAS...AND IS BASICALLY UNMOVED FROM 24 HOURS AGO. WEAKENING SURFACE RIDGING CENTERED A FEW HUNDRED MILES EAST OF THE LOWER TEXAS COAST IS CONTINUING TO PROVIDE A BREEZY DAY ACROSS THE REGION WITH THE THERMAL LOW SET UP EAST OF THE SIERRA MADRE MOUNTAINS. WITH THIS PATTERN WE REMAIN HOT AND BREEZY WITH FLOW FROM THE SOUTH SOUTHEAST. LOW LEVEL MOISTURE IS SLOWLY CREEPING IN...AND WE DO HAVE A LITTLE BETTER CUMULUS COVERAGE THAN WE DID THURSDAY...WITH SLIGHTLY MORE VERTICAL EXTENT...BUT THE SUBSIDENCE FROM UPPER RIDGING AND CONTINUAL MIXING OF DRIER AIR FROM THE MID AND LOWER LEVELS TO THE SURFACE IS KEEPING US DRY. A BUMP UP IN 700-850MB WINDS TONIGHT SHOULD KEEP BREEZES GOING A LITTLE LATER THAN NORMAL TODAY...LIKELY NOT SUBSIDING TOTALLY UNTIL AROUND 10 PM OR MIDNIGHT. A FEW VERY ISOLATED SHOWER MAY SPREAD INTO THE GULF WATERS...BUT EXPECT LAND AREAS TO STAY DRY. TOMORROW LITTLE CHANGE IS ANTICIPATED IN THE SYNOPTIC PATTERN...WITH THE UPPER RIDGE MOVING VERY SLIGHTLY WESTWARD IF AT ALL...AND THE SURFACE RIDGING TO THE EAST SLACKENING SLIGHTLY. OUR OVERALL MOISTURE NUDGES UPWARD A BIT...BUT FORECAST SOUNDINGS SHOW WE WOULD STILL NEED MECHANICAL LIFTING TO GET PARCELS GOING AND OUR GRADIENT SHOULD BE TOO STRONG TO GET A SOLID SEABREEZE BOUNDARY SET UP SO KEPT FORECAST HOT AND DRY. ANOTHER ROUND OF ISOLATED GULF SHOWERS IS POSSIBLE SATURDAY NIGHT. .LONG TERM.../SUNDAY THROUGH FRIDAY/... UPPER LEVEL RIDGE OVER CENTRAL TEXAS FLATTENS AND MOVES WEST INTO THE FOUR CORNERS REGION SUNDAY INTO MONDAY. SURFACE HIGH OVER THE GULF WEAKENS PROVIDING A MORE LIGHTER SE FLOW ALONG THE WEST GULF COAST SUNDAY AFTERNOON. NAM12 SHOWS THE LATEST PWATS VALUES ABOVE 2 INCHES ALONG THE COASTAL COUNTIES SUNDAY. THIS WILL SET THE STAGE FOR SEABREEZE CONVECTION SUNDAY AFTERNOON. CHANCES OF RAIN WILL REPEAT MONDAY AS CONDITIONS ARE FAVORABLE FOR A FEW SHOWERS ONCE AGAIN. CHANCES DECREASE BY MID WEEK AS PWATS LOWER AROUND 1.5 IN AFTER WEDNESDAY WITH A STRENGTHENING CAP OVER THE RGV. THROUGH THE WEEK REALLY HOT TEMPERATURES CONTINUE FOR THE CWA REMAINING IN THE MID TO UPPER 100S WITH LOWS REACHING THE MID TO UPPER 70S. RIDGE WILL SHIFT FURTHER WEST KEEPING DRIER AIR INTO THE PACIFIC NORTHWEST. TROPICAL STORM ERNESTO SOUTH OF THE GREAT ANTILLES WILL MOVE WNW IN THE NEXT COUPLE OF DAYS. AT THIS TIME COOLER AND DRY AIR MAY INHIBIT ANY GROWTH IN THE NEXT COUPLE OF DAYS. && .MARINE...SMALL CRAFT EXERCISE CAUTION CONDITIONS WILL CONTINUE THIS AFTERNOON ON THE LAGUNA WITH SCEC CONDITIONS...AND POSSIBLY WIND CRITERIA FOR SMALL CRAFT ADVISORY BEING MET OVERNIGHT ON THE GULF WATERS. SEAS SHOULD NOT HAVE TIME TO RISE SIGNIFICANTLY WITH WAVE HEIGHTS UP TO AROUND 5 FEET BY SUNRISE IN PLACES. ANOTHER DAY OF SCEC CONDITIONS ON THE LAGUNA DURING THE DAY AND GULF WATERS DURING THE NIGHT IS LIKELY ON SATURDAY. SUNDAY THROUGH FRIDAY... MARINE CONDITIONS REMAIN QUIET THROUGH THE LONG TERM PERIOD AT THIS TIME. HIGH PRESSURE OVER THE GULF SHIFT EAST WEAKENING PRESSURE GRADIENT ALONG THE COASTLINE. EXPECT A LIGHT EASTERLY FLOW THROUGH THE WEEK WITH LIGHT TO MODERATE SEAS. ISOLATED SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP SUNDAY AFTERNOON THROUGH TUESDAY. && .FIRE WEATHER...ANOTHER DAY OF ENHANCED FIRE DANGER IS POSSIBLE ON SATURDAY. AFTERNOON MIN RH VALUES SHOULD BE A LITTLE HIGHER THAN FRIDAY...AND WINDS ARE EXPECTED TO REMAIN BELOW CRITICAL THRESHOLDS. HOWEVER PERSISTENT SOUTHEAST WINDS AND LOW RH MAY COMBINE WITH DRY FUELS...ESPECIALLY ALONG AND JUST WEST OF THE HIGHWAY 281 CORRIDOR TO CREATE ELEVATED FIRE GROWTH POTENTIAL ON SATURDAY AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 95 80 95 81 / 10 10 10 20 BROWNSVILLE 97 79 96 79 / 10 10 10 10 HARLINGEN 101 78 100 78 / 10 10 10 10 MCALLEN 104 79 102 79 / 0 0 10 10 RIO GRANDE CITY 105 80 103 79 / 0 0 0 10 SOUTH PADRE ISLAND 87 81 89 82 / 10 10 10 20 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531526 (Received by flhurricane at: 2:24 PM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 216 PM EDT FRI AUG 3 2012 .SYNOPSIS... VERY WARM AND HUMID WEATHER WILL PERSIST THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND THUNDERSTORMS...BUT SHOWERS AND THUNDERSTORMS ARE MORE LIKELY MONDAY WHEN A COLD FRONT CROSSES SOUTHERN NEW ENGLAND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST BY THURSDAY. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... 215 PM UPDATE... NOT MUCH CHANGE FROM PREVIOUS FORECAST...VERY WARM AND HUMID WEATHER CONTINUES WITH HIGHS ALREADY IN THE L90S AWAY FROM THE IMMEDIATE COAST. FOG/STRATUS HAS FINALLY BURNED OFF ACROSS THE CAPE AND ISLANDS. CONVECTION CONTINUES TO STRUGGLE TO FIRE ANYWHERE ACROSS NEW ENGLAND. ONLY STORMS SO FAR OCCURRED OVER LONG ISLAND NY ON SEABREEZE BOUNDARY. MODELS /INCLUDING 15Z HRRR/ CONTINUE TO FOCUS ANY CONVECTION THIS AFTERNOON INTO EARLY EVENING ACROSS NORTHERN MA INTO SOUTHWEST NH AS WEAK SURFACE TROUGH OVER THIS AREA PROVIDES SOME CONVERGENCE AS A FOCUS. GIVEN DEEP LAYER SHEAR IS ALMOST NIL ANY CONVECTION WILL BE DISORGANIZED AND MAINLY SUB- SEVERE WITH MAIN HAZARD BEING BRIEF HEAVY RAIN. && .SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/... ISOLATED SHOWERS/STORMS WILL BE SLOW TO DIMINISH THIS EVENING DESPITE LOSS OF DAYTIME HEATING DUE TO PLENTY OF LOW LEVEL MOISTURE AND WEAK CONVERGENCE ALONG DISSIPATING FRONT. SHOULD SEE ANOTHER NIGHT OF LOW CLOUDS AND PATCHY FOG...MAINLY NEAR S COAST. USED A BLEND OF GFS/NAM MOS WHICH ARE CLOSE TO EACH OTHER. COLD FRONT WILL HAVE WASHED OUT OVER SOUTHERN NEW ENGLAND SAT...BUT SHOULD STILL BECOME A FOCUS FOR SCATTERED SHOWERS AND STORMS ONCE AGAIN. MODELS INDICATE THIS MAY BEGIN A BIT EARLIER THAN TODAY...BY MID TO LATE MORNING...AS SOME WEAKENING UPSTREAM CONVECTION COMES INTO PLAY. LOOKS LIKE ANOTHER DAY WITH POTENTIALLY HIGH CAPE AND WEAK SHEAR BUT WITH BETTER MID LEVEL LAPSE RATES...SO POTENTIAL FOR GUSTY WINDS AND HAIL MAY BE A LITTLE HIGHER THAN TODAY. LEANED CLOSER TO GFS MOS FOR HIGHS GIVEN EXPECTED CLOUD COVER AND A POSSIBLE EARLIER START TO CONVECTION...IN 80S TO AROUND 90. && .LONG TERM /SUNDAY THROUGH THURSDAY/... HIGHLIGHTS... * QUIET AND MILD SAT NGT * RAIN BECOMING WIDESPREAD SUN-MON ALONG AND AHEAD OF A COLD FRNT * HEAVY RAIN EXPECTED...FLOODING IS A DISTINCT POSSIBILITY * ENERGY OFFSHORE AROUND TUE MORN...QUIET WX EXPECTED INTO WED * ANOTHER DISTURBANCE PSBL INTO THE END OF THE WEEK MODEL DIAGNOSIS... MDL SOLNS ARE STILL TRENDING WITH A PERSISTENT GENERAL PATTERN OF A DEEP POLAR VORTEX ACROSS THE NRN HUDSON BAY RGN WITH A SERIES OF DISTURBANCES ROTATING AROUND THE PERIMETER AND ACROSS THE NERN CONUS. MEANWHILE STRONG RIDGING PERSISTS THRU THE ATLANTIC AND WRN ROCKIES. THE MID-HIGH LATITUDE BLOCKING PATTERN KEEPS AN ACTIVE PATTERN FOR THE FCST. BUT WATCHING A PSBL EWD SHIFT IN THE PATTERN OVER THE NWRN CONUS BY THE FOLLOWING WEEK AS A SERIES OF DISTURBANCES PROMOTE DEEP TROUGHING THRU THE GULF OF ALASKA...CONSEQUENTIALLY SHIFTING THE MAIN RIDGE OF HIGH PRES ACROSS THE CENTRAL CONUS TOWARDS THE ERN CONUS. OVERALL...WHILE MDL SOLN CONTINUITY HAS PERSISTED INTO THE BEGINNING OF NEXT WEEK WITH THE 02/12Z GUIDANCE...THEREAFTER IT HAS REMAINED UNCERTAIN DUE TO RUN TO RUN VARIABILITY OF TIMING/PHASING OF KEY FEATURES ACROSS THE MID-HIGH LATITUDES. HPC HAS EMPHASIZED A MORE CONSENSUS APPROACH WITH EQUAL WEIGHTING OF DETERMINISTIC AND ENSEMBLE MDL SOLNS. OF GREATER CERTAINTY...MDL SOLNS IN BETTER AGREEMENT OF ACTIVITY INITIATING SUNDAY AND CONTINUING SUNDAY NIGHT INTO MONDAY WITH THE APPROACH OF A SFC COLD FRNT. AM STILL CONCERNED OVER THE PROLONGED PERIOD OF SUB-TROPICAL MOISTURE FETCH NEWD ACROSS NEW ENGLAND AHEAD OF THE COLD FRNT /PWATS AROUND 2.25 IN/ WARRANTING THE POSSIBILITY OF FLOOD WATCHES. BETTER AGREEMENT OF THE COLD FRNT AND ATTENDANT ENERGY OFFSHORE BY TUE MORN. AND FINALLY...THERE IS ALSO SLIGHTLY BETTER CONSENSUS OF A FOLLOW UP DISTURBANCE BY THE END OF THE WEEK. SATURDAY NIGHT... CONVECTIVE ELEMENTS DURING THE DAY DIMINISH AS WEAK HIGH PRES TAKES CONTROL. SLY FLOW ENHANCING THRU THE EVNG IN RESPONSE TO THE APPROACHING SYNOPTIC SYS ACROSS THE GRT LKS BY SUNDAY MORN. WILL SEE A SURGE OF LOW 70 DEWPOINTS TOWARDS THE S SHORE OF NEW ENGLAND. CANT RULE OUT THE DEVELOPMENT OF LOW STRATUS AND FOG FOR SHORELINE COMMUNITIES. SHOULD BE A MILD NIGHT WITH MINS RANGING FROM THE UPR 60S TO LOW 70S /MID 70S PSBL/. SUNDAY THROUGH MONDAY... THE COMBINATION OF ENHANCED LOW-MID LVL FLOW OF SUB-TROPICAL AIR FROM THE SERN CONUS ON SUNDAY CONVERGENT ALONG A PSBL PRE-FRONTAL TROUGH...AND DESTABILIZATION OF THE LOCAL BOUNDARY LYR...WARRANTS CHC POPS FOR SUNDAY INTO SUNDAY NGT. ADVERTISED PWATS DURING THIS TIMEFRAME ARE AROUND 2 INCHES WITH MDL SOUNDINGS INDICATED A FAIRLY MOIST ADIABATIC PROFILE WITH THIN ELONGATED CAPE THRU THE ATMOS COLUMN OF 500-1000 J/KG. PRESENT THINKING IS FOR SHOWERS AND THUNDERSTORMS TO INCREASE IN AERIAL COVERAGE THRU THE DAY ACROSS THE MID-ATLANTIC NEWD INTO NEW ENGLAND. BEST POP CHCS WILL BE OVER WRN AND CENTRAL NEW ENGLAND. WHILE STORMS /LIKELY PULSY IN NATURE/ ARE EXPECTED TO BE SUB-SEVERE...HEAVY RAIN WILL BE A THREAT. ACTIVITY SHOULD CONTINUE SUNDAY NIGHT INTO MONDAY ALONG AND AHEAD OF THE COLD FRNT FCST TO SLIDE THRU THE RGN AND OFFSHORE BY TUE MORN. FRONTOGENETICAL FORCING OF CONTINUED LOW-MID LVL SWLY ADVECTION OF SUB-TROPICAL AIR SHOULD LEND TO LIKELY POPS FOR SHOWERS AND THUNDERSTORMS. SOME UNCERTAINTY AS TO WHETHER CLOUDS WILL BREAK ALLOWING FOR DESTABILIZATION OF THE BOUNDARY LYR ON MONDAY. NEVERTHELESS THE POSSIBILITY FOR ELEVATED CONVECTION EXISTS WITH CAPE VALUES HOVERING AROUND 500-1000 J/KG WITHIN A VERY MOIST ADIABATIC ENVIRONMENT. EXPECTED EMBEDDED HEAVIER RAINS WITH PULSE TYPE CONVECTION. PWATS ADVERTISED AROUND 2.25 INCHES AHEAD OF THE COLD FRNT WARRANT THE POSSIBILITY OF FLOODING. TUESDAY AND TUESDAY NIGHT... LOOKS TO REMAIN DRY WITH WEAK HIGH PRES ACROSS THE RGN IN WAKE OF MONDAYS DISTURBANCE SITTING OFFSHORE OF NEW ENGLAND. SLIGHTLY COOLER AND DRIER AIR BUILDS INTO THE RGN /H85 TEMPS AROUND +14C/. LGT AND VRB W/SWLY FLOW. WEDNESDAY THROUGH FRIDAY... A SECOND DISTURBANCE WITH ATTENDANT COLD FRNT IS EXPECTED TO SLIDE THRU THE RGN...USURPING ONCE AGAIN BETTER SUB-TROPICAL MOISTURE FROM THE SERN CONUS. MDL SOLNS VARY WITH OUTCOMES BASED ON EVOLUTION OF MID-LYR FEATURES THRU THE MID-HIGH LATITUDES. AM SOMEWHAT HESITANT TO ACCEPT THE 03/0Z GFS SOLN...RATHER AM MORE FAVORABLE TO THE SIMILAR TRENDS PER 03/0Z CANADIAN AND 02/12Z ECMWF. WILL HINT AT PRECIP FOR WED-THURS...WITH IMPROVEMENT FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND WITH ACTIVITY SHUNTED OFFSHORE BY HIGH PRES BUILDING S OUT OF CANADA. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW...MODERATE CONFIDENCE. VFR THROUGH THIS EVENING WITH JUST A LOW PROB OF BRIEF MVFR IN ISOLATED TSTM TIL 01Z. TONIGHT...CONFIDENCE IS LOW ON IFR REDEVELOPING. THINKING ANY IFR CONDITIONS WILL BE CONFINED TO SOUTH COAST INCLUDING CAPE COD AND THE ISLANDS. SAT...ANY IFR CAPE COD AND ISLANDS WILL BURN OFF BY MIDDAY. OTHERWISE VFR WITH JUST A LOW PROB OF AN ISOLATED TSTM IN THE AFTN. KBOS TAF...MODERATE CONFIDENCE. VFR WITH JUST A LOW PROB OF A BRIEF MVFR IN TSTM TIL 01Z. OTHERWISE VFR TONIGHT AND SAT. LOW PROB AGAIN OF AN ISOLATED TSTM SAT AFTN. KBDL TAF...MODERATE CONFIDENCE. VFR MUCH OF THE TIME. THE EXCEPTIONS WILL BE A LOW PROB OF BRIEF MVFR IN TSTM TODAY TIL 01Z...THEN LOW PROB OF IFR CONDITIONS IN FOG TONIGHT 06Z-12Z AND THEN AGAIN LOW PROB OF AN ISOLATED MVFR TSTM SAT AFTN. VFR LIKELY SAT NIGHT. OUTLOOK...SUNDAY THROUGH TUESDAY... SUNDAY THROUGH MONDAY...MODERATE CONFIDENCE. INCREASING AERIAL EXTENT OF SHRA/TSRA ALONG AND AHEAD OF AN APPROACHING COLD FRNT FROM THE W. SHRA/TSRA MAY BE HEAVY AT TIMES... ESPECIALLY MONDAY AS THE COLD FRNT TRAVERSES THE TERMINALS... PUSHING OFFSHORE BY TUE MORN. PREVAILING MVFR-VFR...TEMPO IFR VSBY IMPACTS WITH +SHRA/+TSRA. ESPECIALLY DURING EVNG PDS...EXPECTING FOG AND LOW STRATUS ALONG THE S COAST WITH IFR-LIFR IMPACTS. STRONG SLY FLOW WITH GUSTS UP TO 25 KTS THRU THE ENTIRE PD. TUESDAY...MODERATE CONFIDENCE. WLY WIND FLOW. PREVAIL VFR. LESSER CHCS FOR FOG AND LOW STRATUS. && .MARINE... FAIRLY CONFIDENT WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH SAT. SW WINDS GUST TO 20KT ALONG S COAST THIS AFTERNOON...WHICH INCLUDES BUZZARDS BAY AND VINEYARD SOUND...BUT PROBABILITY OF REACHING 25KT IS LOW. SEAS WILL CONTINUE TO BUILD SLOWLY ON S COASTAL WATERS DUE TO PERSISTENT SW FLOW BUT ARE NOT EXPECTED TO REACH 5 FT. MAIN HAZARDS INCLUDE SCATTERED TSTMS THIS AFTERNOON AND SAT AFTERNOON...MAINLY FROM NARRAGANSETT BAY TO BOSTON HARBOR AND MERRIMACK RIVER...AND PATCHY DENSE FOG ON S COASTAL WATERS LATE TONIGHT AND SAT MORNING. OUTLOOK...SUNDAY THROUGH TUESDAY... INCREASING SLY FLOW ALONG AND AHEAD OF AN APPROACHING COLD FRNT WILL RESULT IN SWELL AND HIGH SEAS ACROSS THE S WATERS /WAVE HEIGHTS OF AROUND 7 FT FOR THE OUTER WATERS...WITH 5-7 FT FOR THE INNER WATERS ALONG THE S COAST/. E WATERS WILL GRADUALLY RISE AS WELL. GUSTS UP TO 25 KTS CAN BE EXPECTED BEGINNING LATE SUNDAY THROUGH TUE BY WHICH POINT THE COLD FRNT WILL HAVE SHUNTED E...TRANSITIONING OUT TO SEA. AERIAL EXTENT OF SHOWERS AND THUNDERSTORMS WILL INCREASE THRU THE PD...BEGINNING SUNDAY. SOME OF THESE STORMS...ESPECIALLY ALONG AND AHEAD OF THE COLD FRNT...WILL BE ASSOC WITH HEAVY RAIN AND REDUCED VSBYS. RAINS AND ACTIVITY SHOULD BE E OF THE WATERS BY LATE MORN INTO MIDDAY TUE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ004>006- 009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...SIPPRELL/JWD |
| #531525 (Received by flhurricane at: 2:23 PM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 220 PM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL INTO EARLY NEXT WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A STATIONARY FRONT WILL STALL NORTH OF THE AREA MID TO LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HAVE MADE A FEW ADJUSTMENTS TO LOWER TEMPS 1-2 DEGREES OVER THE FORECAST AREA BASED ON EXPANSIVE THIN CIRRUS SEEN ON THE LATEST VIS SAT IMAGERY. OVERALL HIGHS WILL STILL REACH THE LOW 90S FOR MANY LOCATIONS OVER INLAND SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA...BUT LOCATIONS OVER DORCHESTER AND BERKELEY COUNTY WILL STRUGGLE TO REACH 90 DEGREES THIS AFTERNOON DUE TO A SMALL CLUSTER OF THUNDERSTORMS MOVING OVER THE AREA. ONCE THESE THUNDERSTORMS SHIFT NORTH OF THE FORECAST AREA...THE MAIN FOCUS OF DEVELOPING CONVECTION WILL LIKELY BE ALONG THE SEABREEZE. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP OVER THE NEXT COUPLE HOURS AS CONVECTIVE TEMPS ARE MET. LOCATIONS WEST OF INTERSTATE 95 IN SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA WILL LIKELY HAVE THE GREATEST COVERAGE OF SHOWER/THUNDERSTORM ACTIVITY THROUGH THE EVENING. CONDITIONS ARE FAVORABLE FOR SBCAPES TO APPROACH 3000-3500 J/KG AND LIFTED INDICES TO REACH AS LOW AS -8C. SHEAR PROFILES WILL REMAIN WEAK THROUGH THIS EVENING. WITH THE LACK OF ANY SIGNIFICANT UPPER SUPPORT ALOFT...PULSE TYPE THUNDERSTORMS WILL BE THE PRIMARY FORM OF CONVECTION ALONG AND AHEAD OF AN INLAND MOVING SEABREEZE. ACTIVITY MAY EVOLVE INTO MORE OF A MULTICELL SCENARIO AS CONVECTIVE OUTFLOWS BEGIN TO INTERACT...ESPECIALLY OVER INLAND LOCATIONS. GIVEN THE AMOUNT OF INSTABILITY ALONG WITH DCAPES BETWEEN 800-1100 J/KG...WBZ HEIGHTS AROUND 12500 FT AND ANTICIPATED BOUNDARY INTERACTIONS...A FEW STORMS MAY BECOME STRONG WITH DAMAGING WINDS AND MARGINAL HAIL UNTIL SUNSET. THE BEST CHANCE OF STRONGER STORMS WILL LAST UNTIL 8 PM THIS AFTERNOON/EVENING. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... ANY LINGERING CONVECTION WILL DISSIPATE BY LATE EVENING WITH THE LOSS OF INSOLATION AND CONVECTIVE OVERTURNING. CAN NOT COMPLETELY RULE OUT AN ISOLATED SHOWER/TSTM FIRING OVERNIGHT GIVEN THE NATURE OF THE AIRMASS IN PLACE...BUT PROBABILITIES FOR MEASURABLE RAINFALL WILL GENERALLY REMAIN LESS THAN 20 PERCENT. DEPENDING ON HOW QUICKLY DEBRIS CLOUDINESS WILL THIN...PATCHY FOG COULD DEVELOP WITHIN A LIGHT WIND REGIME. LOWS WILL RANGE FROM THE LOWER 70S INLAND TO THE UPPER 70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON. THE SOUTHEAST STATES WILL REMAIN BETWEEN TWO UPPER LEVEL RIDGES THROUGH THE WEEKEND...WITH THE WESTERN RIDGE LOCATED OVER THE CENTRAL PLAINS AND THE EASTERN RIDGE CENTERED OVER THE ATLANTIC WATERS. AT THE SURFACE...ATLANTIC HIGH PRESSURE WILL EXTEND OVER THE MID ATLANTIC AND SOUTHEAST STATES...AS A WEAK INLAND TROUGH TAKES SHAPE BY MONDAY. THIS TYPICAL SUMMERTIME PATTERN WILL SUPPORT A GENERAL SOUTH- SOUTHEAST ONSHORE FLOW AND ALLOW THE DAILY INLAND PROGRESSION OF THE SEABREEZE. EXPECT PULSE TYPE SHOWERS AND THUNDERSTORMS TO INITIATE EACH AFTERNOON AND EVENING...DRIVEN MAINLY BY SEABREEZE CONVERGENCE...MESOSCALE BOUNDARY INTERACTIONS AND DIURNAL HEATING/INSTABILITY. WEAK SHORTWAVE ENERGY ON SATURDAY WILL MOVE OUT OF THE AREA BY SUNDAY AND MONDAY AS THE ATLANTIC RIDGE BUILDS WESTWARD...LEAVING LITTLE UPPER LEVEL SUPPORT THROUGH THE SHORT TERM PERIOD. AS A RESULT...ANY ISOLATED TO SCATTERED CONVECTION WILL DIMINISH IN COVERAGE WITHIN WANING HEATING/INSTABILITY BY SUNSET. HAVE MAINTAIN SHOWER/THUNDERSTORM CHANCES IN THE 20 TO 30 PERCENT RANGE EACH DAY. ALTHOUGH AN ISOLATED STRONG STORM IS POSSIBLE WITH THIS PULSE TYPE CONVECTION AND BOUNDARY INTERACTIONS...THE OVERALL SEVERE WEATHER THREAT WILL REMAIN LOW OVER THE PERIOD. HIGH TEMPERATURES WILL REACH THE LOWER 90S EACH AFTERNOON AWAY FROM THE LOCALLY COOLER COASTLINE...WHILE LOW TEMPERATURES ONLY FALL INTO THE LOW TO MID 70S. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... UPPER LEVEL RIDGING WILL BEGIN TO WEAKEN EARLY NEXT WEEK...AS A TROUGH ALOFT AND SEVERAL SHORTWAVES MOVE ACROSS THE NEW ENGLAND STATES. AN ASSOCIATED COLD FRONT WILL LIKELY STALL WELL TO THE NORTH OF THE FORECAST AREA BY THE MIDDLE OF NEXT WEEK. AT THE SURFACE...THE INLAND TROUGH COULD BECOME MORE PROMINENT BETWEEN SURFACE HIGH PRESSURE OVER THE CENTRAL UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. CONSIDERING THE INCREASED FORCING FROM THE STALLED FRONT TO THE NORTH...COMBINED WITH INFLUENCES FROM THE LEE TROUGH AND BOUNDARY/SEABREEZE INTERACTIONS...CONVECTIVE POTENTIAL COULD BE GREATER THROUGH THE EXTENDED PERIOD. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS...WITH HIGH TEMPERATURES IN THE LOW TO MID 90S DURING THE AFTERNOON FALLING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... PRIMARILY VFR AT BOTH TERMINALS. ONCE AGAIN...THUNDERSTORMS WILL BE AROUND BOTH KCHS AND KSAV TODAY BUT COVERAGE AND INTENSITY LOOK TO BE LESS TODAY COMPARED TO THE LAST FEW DAYS. THE CONTINUOUS SOUTHERLY FLOW TODAY SHOULD LIMIT THE CONVERGENCE WITH THE SEABREEZE. HOWEVER...THE PRESENCE OF OUTFLOW BOUNDARIES FROM PREVIOUS STORMS COULD TRIGGER THUNDERSTORM DEVELOPMENT. MODELS HAVE THE BULK OF THE ACTIVITY FURTHER INLAND...THUS...WILL HOLD OFF ON THUNDER OVER THE TERMINALS. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER THAN 30 PERCENT CONFIDENCE LEVEL AT THIS TIME. && .MARINE... THERE ARE NO MARINE CONCERNS THROUGH TONIGHT. A BROAD SOUTHERLY FLOW REGIME WILL DOMINATE WITH WINDS GENERALLY 10-15 KT AND SEAS 2-3 FT. ATLANTIC HIGH PRESSURE WILL EXPAND OVER THE WATERS THIS WEEKEND...SUPPORTING CONDITIONS BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO EARLY NEXT WEEK. IN GENERAL...SOUTH WINDS BETWEEN 10-15 KT WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE...WITH HIGHEST WINDS EXPECTED NEAR THE INLAND MOVING SEABREEZE CIRCULATIONS AND EARLY NOCTURNAL SURGES. WINDS COULD BRIEFLY BECOME SOUTHEAST EACH AFTERNOON/EVENING AS THE SEABREEZE PUSHES INLAND. SEAS WILL REMAIN BETWEEN 1-3 FT...WITH SWELLS FROM THE SOUTH/SOUTHEAST. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531524 (Received by flhurricane at: 2:12 PM 03.Aug.2012) AFDSJU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 211 PM AST FRI AUG 3 2012 .SYNOPSIS...AT 2 PM AST...TROPICAL STORM ERNESTO WAS LOCATED NEAR LATITUDE 13.7 NORTH...LONGITUDE 62.3 WEST AND WAS MOVING TOWARD THE WEST AT NEAR 21 MPH. ERNESTO IS EXPECTED TO MOVE GENERALLY WEST FOR THE NEXT COUPLE OF DAYS...WITH A GRADUAL DECREASE IN FORWARD SPEED. ON THE FORECAST TRACK...ERNESTO WILL MOVE ACROSS THE EASTERN CARIBBEAN OVERNIGHT THROUGH SATURDAY...BRINGING OUTER BANDS OF MOISTURE TO THE LOCAL AREA...WITH CLOUDINESS...SHOWERS AND THUNDERSTORMS AND INCREASINGLY BREEZY TO WINDY CONDITIONS.. UPPER LEVEL HIGH PRESSURE RIDGE WILL REMAIN IN PLACE ACROSS THE NORTHEASTERN CARIBBEAN THROUGH AT LEAST SATURDAY. IT IS THEN EXPECTED TO GRADUALLY ERODE LATE SUNDAY INTO EARLY NEXT WEEK...AS TUTT AND ASSOCIATED LOW ACROSS THE CENTRAL ATLANTIC RETROGRESSES WESTWARD OVER THE REGION. SURFACE HIGH PRESSURE NORTH OF THE AREA AND TROPICAL STORM ERNESTO NOW ENTERING THE EASTERN CARIBBEAN WILL MAINTAIN AN EAST TO NORTHEAST WIND FLOW ACROSS THE REGION. THIS WILL RESULT IN THE SURFACE PRESSURE GRADIENT RAPIDLY TIGHTENING OVERNIGHT THROUGH SATURDAY. LATEST VISIBLE SATELLITE IMAGERY AND BLENDED TOTAL PRECIPITABLE WATER SHOWED THAT MID TO UPPER LEVEL MOISTURE ACROSS THE NORTHEAST HAS BEGUN TO INCREASE DURING THE AFTERNOON IN ADVANCE OF THE TROPICAL STORM. && .DISCUSSION...OVERALL FAIR AND STABLE WEATHER CONDITIONS DOMINATED THE LOCAL AREA TODAY AS HIGH PRESSURE RIDGING AND SUBSIDENCE IN ADVANCE OF TROPICAL STORM ERNESTO LIMITED SHOWER DEVELOPMENT. EXPECT PARTLY CLOUDY SKIES TO VARIABLY CLOUDY DURING THE EARLY EVENING WITH INCREASING CLOUDINESS AND DETERIORATING CONDITIONS LATER THIS EVENING AND OVERNIGHT THROUGH SATURDAY AS ERNESTO AND ASSOCIATED MOISTURE FIELD SPREADS ACROSS THE EASTERN CARIBBEAN. THE TIGHTENING OF THE LOCAL PRESSURE GRADIENT WILL BRING BREEZY TO LOCALLY WINDY CONDITIONS TO THE REGION. IN ADDITION...DEEP MOISTURE ALONG THE NORTH AND EAST PERIPHERY OF THE TROPICAL STORM WILL BE LIFTED UP ACROSS THE AREA...INCREASING THE CHANCES FOR ACTIVE AND INCLEMENT WEATHER CONDITIONS. BASED ON PRESENT LATEST MODEL GUIDANCE...EXPECT THESE CONDITIONS TO BEGIN DURING THE EARLY EVENING ACROSS THE NORTHERN LEEWARD AND VIRGIN ISLANDS. THEREAFTER...IT WILL PROGRESSIVELY INCREASE IN COVERAGE AND SPREAD WEST AND NORTH ACROSS PUERTO RICO AND ADJACENT ISLANDS ON SATURDAY. INFREQUENT BURSTS OF GUSTY WINDS AND LOCALLY HEAVY RAINFALL MAY OCCUR FROM TIME TO TIME OVERNIGHT ACROSS THE COASTAL WATERS AND THE COASTAL SECTIONS OF THE ISLANDS.HOWEVER... THE HEAVIEST RAINFALL IS EXPECTED EARLY SATURDAY MORNING AND CONTINUING INTO EARLY SUNDAY. DURING THAT TIME...PERIODS OF NUMEROUS SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL AND STRONG GUSTY WINDS ALONG WITH SQUALLS ACCOMPANYING THE BANDS OF SHOWERS AND THUNDERSTORMS. && .AVIATION...TROPICAL STORM ERNESTO WILL CONTINUE TO MOVE SOUTH OF THE LOCAL ISLANDS THIS EVENING THROUGH SATURDAY. SOME OF THE OUTER BANDS WILL AFFECT THE VI TAF SITES LATE THIS EVENING SPREADING OVER PR TOMORROW MORNING. LLVL WINDS WILL REMAIN FROM THE NORTHEAST THRU TONIGHT...VEERING FROM THE EAST TO SOUTHEAST EARLY SATURDAY THRU SUNDAY. SFC WINDS OF 15 TO 25 KTS WITH HIGHER GUSTS UP TO 40 KTS WILL REMAIN POSSIBLE DURG THE NEXT 24-48 HRS DURG PASSAGE OF TS ERNESTO. && .PRELIMINARY POINT TEMPS/POPS... SJU 88 78 87 78 / 50 80 80 60 STT 81 79 88 79 / 50 50 50 30 && .SJU WATCHES/WARNINGS/ADVISORIES... PR... VI...NONE. COASTAL WATERS...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM AST SUNDAY FOR ANEGADA PASSAGE SOUTHWARD TO 17N. SMALL CRAFT ADVISORY FROM 11 AM TO NOON AST SATURDAY FOR COASTAL WATERS OF NORTHERN PUERTO RICO OUT 10 NM-COASTAL WATERS OF NORTHWESTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM AST SUNDAY FOR COASTAL WATERS OF SOUTHERN USVI VIEQUES AND EASTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO NOON AST SUNDAY FOR CARIBBEAN WATERS OF PUERTO RICO FROM 10 NM TO 17N. SMALL CRAFT ADVISORY FROM 2 AM SATURDAY TO NOON AST SUNDAY FOR COASTAL WATERS OF SOUTHERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM NOON SATURDAY TO NOON AST SUNDAY FOR COASTAL WATERS OF SOUTHWESTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON AST SUNDAY FOR ATLC WATERS OF PUERTO RICO AND USVI FROM 10NM TO 19.5N- MONA PASSAGE SOUTHWARD TO 17N. SMALL CRAFT ADVISORY FROM 6 AM SATURDAY TO 6 AM AST SUNDAY FOR COASTAL WATERS OF NORTHERN USVI AND CULEBRA OUT 10 NM. && $$ |
| #531523 (Received by flhurricane at: 2:09 PM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 158 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHENS OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARM TO HOT TEMPS...HIGH DEW POINTS IN THE 70S HAVE RESULTED IN SFC BASED CAPES AROUND 3K TO 4K J/KG ACROSS LONG ISLAND. ISOLATED SHOWERS AND TSTMS COULD CONTINUE TO FORM ON THE SEA BREEZE BOUNDARY...AND THE MAIN FORMATION SHOULD BE ACROSS THE INTERIOR AS THE AFTERNOON PROGRESSES. THE OTHER TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA. HEAT INDEX VALUES ALREADY AROUND 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. TEMPS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD WITH MAINLY VFR EXPECTED. THE ONLY EXCEPTION WILL BE SOME EARLY MORNING MVFR OR IFR FOG. ANY SUB-VFR CIGS ARE EXPECTED TO IMPROVE TO VFR BY 13Z-15Z. AN ISOLATED THUNDERSTORM IS POSSIBLE AT ANY TIME FROM THIS AFTERNOON INTO THE EARLY EVENING. ANY ADDITIONAL DEVELOPMENT WOULD LIKELY BE ALONG THE SEA BREEZE CONVERGENCE OVER LONG ISLAND OR ACROSS THE LOWER HUDSON VALLEY. HRRR KEEPS LOOKING TO BRING SOME ACTIVITY ACROSS THE LOWER HUDSON VALLEY AND WESTERN NJ ACROSS NYC LATER THIS AFTERNOON HOWEVER STILL NOT CONFIDENT ENOUGH CONFIDENCE TO INCLUDE ANY ACTIVITY IN THE TAFS. CIRRUS STREAKING EASTWARD ACROSS PA ATTM MAY ALSO HELP TO INHIBIT ADDITIONAL CU DEVELOPMENT IN THE IMMEDIATE VICINTY OF THE TERMINALS. WINDS ARE GENERALLY SW UNDER 10 KT THROUGH THE PERIOD. DURING THE AFTERNOON...SEA BREEZES ARE EXPECTED TO SHIFT WINDS MORE SOUTHERLY AND INCREASE SLIGHTLY. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: FORECAST ON TRACK. NO UNSCHEDULED AMENDMENTS ANTICIPATED. KLGA FCSTER COMMENTS: FORECAST ON TRACK. NO UNSCHEDULED AMENDMENTS ANTICIPATED. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFTS. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFTS. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFTS. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFTS. ALSO NEARBY ISOLATED SHOWERS MAY REQUIRE AMENDMENTS IF THEY PASS NEAR THE AIRPORT. OUTLOOK FOR 18Z SAT THROUGH WED... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS....MAINLY IN THE AFTERNOON. LATE DAY TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE/WED...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...NV/DW |
| #531521 (Received by flhurricane at: 2:08 PM 03.Aug.2012) AFDTBW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL 200 PM EDT FRI AUG 3 2012 .SYNOPSIS)... 18Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE FLORIDA PENINSULA CONTINUES TO RESIDE UNDERNEATH A SUBTLE WEAKNESS IN THE HEIGHT FIELDS TO THE EAST OF AN IMPRESSIVE AND DOMINANT UPPER LEVEL RIDGE ACROSS THE SOUTHERN PLAINS. THIS UPPER RIDGE IS ACTUALLY ONE OF THE MORE VISUALLY IMPRESSIVE ANTICYCLONES ON WV IMAGERY THAT THIS FORECASTER HAS SEEN...WITH A VERY SYMMETRIC LOOK OF DRY AIR/SUPPRESSION AT ITS CORE AND RINGED BY A MID/UPPER LEVEL MOISTURE BELT. AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS HAS SHIFTED NORTHWARD OVER THE PAST 24 HOURS AND IS NOW ALIGNED OVER THE NORTHERN FL PENINSULA/NE GULF OF MEXICO. ROTATING AROUND THE SOUTHERN PERIPHERY OF THIS RIDGE WE FIND A RATHER WELL DEFINED INVERTED TROUGH/TROPICAL WAVE FEATURES CROSSING THE BAHAMAS AND APPROACHING THE FL EAST COAST. && .SHORT TERM (THIS EVENING THROUGH SUNDAY NIGHT)... LATE AFTERNOON/EVENING...THE CURRENT THINKING ON THE MOST LIKELY CONVECTIVE CYCLE THROUGH THE EVENING IS FOR ISOLATED-WDLY SCT SHOWERS/STORMS EARLY/MID AFTERNOON MOVING SLOWLY INLAND FROM THE I-75 CORRIDOR. THEREAFTER...WITH THE APPROACH OF THE SURFACE WAVE FROM THE EAST...WILL SEE OUR 1000-700MB FLOW TRANSITION TO A MORE EASTERLY DIRECTION. THIS SYNOPTIC INFLUENCE SHOULD HELP PROPEL THE EAST COAST SEA-BREEZE ACROSS THE PENINSULA BY EARLY EVENING. THE INTERACTION OF BOTH SEA-BREEZES SHOULD BE GREATEST FROM TAMPA BAY SOUTHWARD WHERE A SECOND ROUND OF CONVECTION MAY ACTUALLY PUSH BACK TOWARD THE WEST COAST WITH TIME. MID-LEVEL CONVECTIVE POTENTIAL IS ACTUALLY VERY FAVORABLE FOR DEEP CONVECTION WITH THETAE VALUES IN THE LOWER 330S. OUR LOCAL HIRES GUIDANCE ALONG WITH SEVERAL OF THE NATIONAL HI-RES MEMBERS ARE SHOWING SOMETHING SIMILAR TO THIS SCENARIO. REST OF THE OVERNIGHT...DEVELOPING EASTERLY FLOW WILL PUSH ANY LINGERING CONVECTION OFFSHORE ALLOWING FOR A MOSTLY DRY OVERNIGHT PERIOD AFTER 02-03Z. NOT IMPOSSIBLE THAT A FEW SHOWERS MOVING ASHORE ALONG THE FL EAST COAST WITHIN THE EASTERLY FLOW COULD REACH FAR EASTERN PORTIONS OF THE AREA...HOWEVER MOST OF THIS ACTIVITY SHOULD DISSIPATE SHORTLY AFTER MOVING INLAND. SATURDAY/SATURDAY NIGHT... TROUGH/WAVE PASSES OVER THE CENTRAL/SOUTHERN PENINSULA AND REACHES THE WESTERN COAST BY EARLY EVENING. THE COMBINATION OF INCREASING COLUMN MOISTURE AND ENHANCED LOW LEVEL FOCUS ASSOCIATED WITH THIS FEATURE IS LIKELY TO RESULT IN A GOOD COVERAGE OF SHOWERS/STORMS DURING THE AFTERNOON/EVENING HOURS. CURRENT GRIDS SHOWING 40-50% POPS NORTH OF TAMPA BAY AND LIKELY 60% POPS FURTHER SOUTH. THE EASTERLY FLOW SHOULD ALSO HELP KEEP THE MAIN CONVECTIVE AXIS FROM MOVING INLAND AND AWAY FROM THE COAST. THEREFORE...WILL KEEP EQUAL CHANCES FOR RAIN THROUGH THE AFTERNOON FOR BOTH COASTAL AND INLAND ZONES. TEMPERATURES WILL BE HIGHLY DEPENDENT ON JUST HOW FAST THE CONVECTION GETS ACTIVE. DO ANTICIPATE QUITE A BIT OF DEBRIS CLOUD COVER BY THE END OF THE DAY. WILL ALLOW TEMPS TO REACH THE LOWER 90S FOR MOST LOCATIONS...HOWEVER ACTUAL HIGHS MAY BE A BIT LOWER. EVENING SHOWER AND STORMS WILL MIGRATE BACK OFFSHORE WITHIN THE EASTERLY FLOW BY THE LATER EVENING HOURS. MOST INLAND LOCATIONS WILL SEE A DRY OVERNIGHT PERIOD...WHILE PLENTY OF SHOWERS/STORMS ARE LIKELY TO BE ONGOING OVER THE COASTAL WATERS. ONE THING TO MENTION...AND ONE POTENTIAL ISSUE WITH THE FORECAST WOULD BE IF THE NAM SOLUTION WERE TO VERIFY. THE NAM IS CONSOLIDATING THE SURFACE WAVE MORE AS IT APPROACHES THE EAST COAST AND ACTUALLY CLOSING OFF A LOW. THIS PATTERN SLOWS THE OVERALL PROGRESS AND MOISTURE INFLUX. THE RESULT WOULD A DRIER FORECAST...ESPECIALLY SINCE THE LACK OF EASTERLY FLOW WOULD LESSEN THE OVERALL CONVERGENCE. AT THIS TIME...THIS SOLUTION IS AN OUTLIER AND WAS NOT CONSIDERED WITH THIS FORECAST PACKAGE. IT IS HARD TO ARGUE WITH A GUIDANCE CONSENSUS WHICH INCLUDES THE GFS/ECMWF/CMC AND SREF. SUNDAY...ANOTHER ACTIVE CONVECTIVE DAY APPEARS ON TAP. THE MAIN AXIS OF THE TROPICAL WAVE WILL HAVE MOVED OFFSHORE INTO THE EASTERN GULF...HOWEVER STILL SOME ENHANCED FOCUS AND A MOIST COLUMN WILL KEEP THE ATMOSPHERE FAVORABLE FOR DEEP CONVECTION. A 1000-700MB LOW LEVEL FLOW WILL ALSO KEEP THE BEST LOW LEVEL CONVERGENCE ALIGNED WITH THE WEST COAST SEA-BREEZE. OVERALL WE ARE NOT ANTICIPATING A WASHOUT OF A WEEKEND...BUT THOSE WITH OUTDOOR PLANS THE NEXT COUPLE OF DAYS SHOULD PREPARE FOR AT LEAST SOME RAINFALL. && .LONG TERM (MONDAY-THURSDAY)... AN U/L RIDGE WILL PERSIST OVER THE ATLANTIC EXTENDING OVER THE SOUTHERN PLAINS THROUGH THE PERIOD. SURFACE HIGH PRESSURE OVER THE WESTERN ATLANTIC WITH THE RIDGE AXIS NORTH OF FLORIDA WILL ALSO PERSIST THROUGH THE PERIOD. EASTERLY BOUNDARY LAYER FLOW WILL HOLD THE WEST COAST SEA BREEZE NEAR THE COAST WITH AFTERNOON BOUNDARY COLLISIONS OVER WEST CENTRAL AND SOUTHWEST FLORIDA. DEEP TROPICAL MOISTURE OVER THE REGION WILL ALLOW NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP MONDAY AND TUESDAY AFTERNOONS. A FEW PULSE SEVERE STORMS ARE POSSIBLE EACH DAY. WILL HAVE TO MONITOR PROGRESS OF TROPICAL STORM ERNESTO NEAR THE WINDWARD ISLANDS AS CURRENT FORECAST TRACKS THE STORM INTO THE WESTERN CARIBBEAN TUESDAY AND WEDNESDAY. SUBSIDENCE AROUND THE PERIPHERY OF THE TROPICAL SYSTEM WILL INCREASE OVER THE FORECAST AREA WEDNESDAY AND THURSDAY WITH DECREASING AREAL COVERAGE OF AFTERNOON THUNDERSTORMS WITH INCREASING DAYTIME TEMPERATURES. DEPENDING ON STRENGTH OF ERNESTO...STRONG SUBSIDENCE AND EASTERLY BOUNDARY LAYER FLOW ACROSS WEST CENTRAL FLORIDA COULD ALLOW AFTERNOON TEMPERATURES TO CLIMB INTO THE MID 90S IN MANY AREAS WEDNESDAY AND THURSDAY. && .AVIATION... HIGHER CONFIDENCE NOW IN THUNDERSTORM ACTIVITY IMPACTING PGD..FMY...RSW AND LAL TAF SITES. TPA...PIE AND SRQ MAY SEE IMPACTS LATER IN THE AFTERNOON OR EVEN INTO THE EARLY EVENING AS EAST COAST ACTIVITY PUSHES WESTWARD. VFR OVERNIGHT AND THROUGH MID-DAY SATURDAY. && .MARINE... THE SUBTROPICAL RIDGE AXIS WILL CONTINUE TO MIGRATE NORTHWARD IN RESPONSE TO THE APPROACH OF A TROPICAL WAVE FROM THE EAST. THIS TROUGH WILL CROSS THE FL PENINSULA INTO THE SOUTHEAST GULF OF MEXICO TONIGHT AND SATURDAY AND THEN REMAIN OVER THE CENTRAL AND EASTERN GULF THROUGH THE REMAINDER OF THE WEEKEND. WINDS WILL BECOME MORE EASTERLY WITH TIME AND ARE GENERALLY EXPECTED TO REMAIN BELOW HEADLINE CRITERIA...HOWEVER THE PRESENCE OF THE SURFACE TROUGH WILL LIKELY INCREASE THE COVERAGE OF SHOWERS AND STORMS OVER THE FORECAST WATERS. && .FIRE WEATHER... AN INFLUX OF LOW LEVEL MOISTURE ASSOCIATED WITH A PASSING TROPICAL WAVE WILL KEEP RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS INTO THE EARLY PORTION OF NEXT WEEK...ALONG WITH DECENT CHANCES FOR MAINLY AFTERNOON AND EVENING SHOWERS AND STORMS. && .PRELIMINARY POINT TEMPS/POPS... TPA 77 92 77 91 / 30 50 20 50 FMY 76 93 76 93 / 30 60 30 50 GIF 74 94 75 94 / 30 50 20 50 SRQ 75 93 75 92 / 30 60 20 50 BKV 71 93 74 92 / 30 50 20 50 SPG 79 92 79 91 / 30 50 20 50 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ |
| #531520 (Received by flhurricane at: 1:57 PM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 149 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... SHORTWAVE TROUGH LOCATED NORTHERN KY/SOUTHERN OH WITH STATIONARY FRONT LOCATED WESTERN VA STRETCHING BACK ACROSS MIDWEST. WEAK UPPER LEVEL LOW CURRENTLY OVER EASTERN NC. SFC HIGH PRESSURE/SOUTHERLY FLOW WILL REINFORCE WARM/HUMID AIRMASS ACROSS THE REGION THIS AFTERNOON RESULTING IN AFTERNOON AND EARLY EVENING SHOWERS/THUNDERSTORMS. STARTING TO SEE SOME CU DEVELOPING ACROSS CENTRAL/WESTERN VA ALREADY. LATEST KWAL SOUNDING DEPICTS PRECIP WATERS AROUND 1.4 INCHES WITH MUCH LESS INSTABILITY THAN YESTERDAY...CAPE VALUES 1500-2000 J/KG AND LI -3 TO -5. TEMPERATURES IN THE 600MB TO 400MB LAYER HAVE WARMED 3-5C OVER THE PAST 24 HRS. LATEST KLWX SOUNDING MORE UNSTABLE WITH BETTER PRECIP WATERS AND LAPSE RATES. LATEST HI RES MODELS/SREF INITIATE CONVECTION IN EASTERN NC NEAR SHORTWAVE/VORT MAX AND LIFT PRECIP NORTHEAST. OUTFLOWS FROM CONVECTION WILL SPREAD SHOWERS/THUNDERSTORMS EWD TOWARD WARM AND UNSTABLE AIRMASS IN PLACE ACROSS CENTRAL VA. HAVE OPTED TO PLACE SCATTERED POPS FROM THE BAY WWD WITH ISOLATED POPS BAY EWD. LATEST MET/MAV GUIDANCE WELL BELOW CLIMO WITH POPS IN THE 10 TO 15 PCT RANGE SO SOME UNCERTAINTY EXISTS. WILL CONTINUE TO WATCH HOW CU FIELD EVOLVES AND ADJUST POPS ACCORDINGLY. CURRENT TEMPS RUNNING 2 TO 4 DEGS BELOW 24 HOURS AGO DUE TO YESTERDAY AFTERNOON/EVENING RAINFALL AND COOLER OVERNIGHT TEMPERATURES. HOWEVER...SOUTHERLY FLOW AND HEIGHT/THICKNESS VALUE INCREASES WILL RESULT IN AFTERNOON TEMPERATURES UPPER 80S TO LOW/MID 90S WITH HEAT INDEX VALUES MID/UPPER 90S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 8-10KT TODAY. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED THROUGH THE AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE. VERY ISOLATED FOG IS POSSIBLE DUE TO RESIDUAL MOISTURE FROM SHOWERS AND TSTMS. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531519 (Received by flhurricane at: 1:57 PM 03.Aug.2012) AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1252 PM CDT FRI AUG 3 2012 .DISCUSSION...UPDATED FOR 18Z AVIATION SECTION BELOW. && .AVIATION...VFR CONDITIONS GENERALLY EXPECTED TO PREVAIL THROUGH THE NEXT 24 HOURS. WINDS INCREASING ONCE AGAIN THIS AFTERNOON AND SHOULD CONTINUE THROUGH THE EARLY EVENING WITH GUSTS TO AROUND 20KTS. FEW/SCT CLOUDS ACROSS THE EAST THIS AFTERNOON AS WELL. WINDS WILL INCREASE OUT WEST THIS EVENING AND OVERNIGHT...FEW/SCT CLOUDS EXPECTED ACROSS THE EAST EARLY SATURDAY MORNING. A BRIEF BKN DECK MAY FORM...BUT CONFIDENCE REMAINS LOW SO WILL KEEP SCT CLOUDS AT THIS TIME. THEN...NEAR REPEAT AGAIN FOR SATURDAY LATE MORNING AND AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 79 96 79 97 77 / 10 20 10 20 10 VICTORIA 76 95 76 96 75 / 0 20 10 30 10 LAREDO 79 103 80 102 79 / 0 10 10 10 10 ALICE 77 100 77 100 76 / 0 10 10 20 10 ROCKPORT 80 93 81 93 79 / 10 20 10 30 10 COTULLA 75 102 76 103 75 / 0 10 10 10 10 KINGSVILLE 78 99 78 99 76 / 0 10 10 20 10 NAVY CORPUS 80 93 81 92 80 / 10 20 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531518 (Received by flhurricane at: 1:56 PM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 152 PM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TODAY AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM FRI...CONVECTIVE INITIATION BEGAN A FEW HOURS EARLY TODAY...SIMILAR TO YESTERDAY...ALONG A WEAK CONVERGENCE LINE FROM PENDER COUNTY NORTH TO GREENE COUNTY. SHOWERS AND WEAK THUNDERSTORMS CONTINUE TO FORM BEHIND AN EASTWARD MOVING OUTFLOW BOUNDARY. THUS HAVE INCREASED POPS TO 50 PERCENT FOR COASTAL PLAIN COUNTIES. TEMPS AND DEWPOINTS ARE FAIRLY CLOSE TO LATEST OBS TO NO CHANGES NEEDED. STILL EXPECT LOWS IN THE LOWER 90S INLAND TODAY. LATEST MSAS ANALYSIS INDICATES A WEAK UPPER LEVEL VORTMAX ACROSS EASTERN NC MIGRATING NORTH...ASSOCIATED WITH A WEAK UPPER LOW WHICH WILL GRADUALLY LIFT OUT TO THE NORTH TODAY. LAPS SOUNDINGS INDICATE A VERY UNSTABLE AIRMASS WITH CAPES OVER 4000 J/KG...LIFTED INDICES NEAR -10 C AND PWATS OF 1.75 INCHES. RECEIVED A COCORAHS HEAVY RAIN REPORT IN ADJACENT PENDER COUNTY EARLIER WITH OVER 1.20 INCHES OF RAIN IN 40 MINS. EXPECT SCATTERED TSTMS TO CONTINUE ALONG INLAND AREAS ASSOCIATED WITH THE ONGOING CONVECTION...THEN WANE THIS EVENING WITH LOSS OF DAYTIME HEATING. OVERNIGHT SHOULD SEE DIMINISHING SHOWERS AND THUNDERSTORMS INLAND WITH WIDELY SCATTERED SHOWERS AND TSTMS POSSIBLE OFF THE COAST. SW FLOW WILL KEEP TEMPS MILD OVERNIGHT WITH LOWS IN THE LOW 70S INLAND TO MID/UPPER 70S ALONG THE COAST. && .SHORT TERM /SATURDAY/... AS OF 140 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON HOURS. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL SHOWERS AND THUNDERSTORMS. && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 12Z SATURDAY/... AS OF 145 PM FRI...MAINLY VFR CONDITIONS EXPECTED TODAY ALTHOUGH MAY SEE BRIEF MVFR IN REDUCED VSBYS AND CEILINGS DUE TO CONVECTION MAINLY FOR OAJ/EWN/ISO. GUIDANCE SUGGEST FOG FORMATION OVERNIGHT GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER. ONLY MINOR MVFR HAS BEEN OBSERVED RECENTLY SO HEDGED TOWARDS CLIMO OF RECENT NIGHTS AND KEPT LOW MVFR FOR FOG OVERNIGHT. SAT WILL SEE CONTINUED S FLOW WITH DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON. LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/ AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH LOCALLY LOWER CEILINGS/VISIBILITIES. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 130 PM FRI...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE LIGHT SE BREEZE 5-10 KNOTS WITH MEDIUM PERIOD SWELLS 2-3 FEET AT 8-9 SECONDS. A LIGHT S/SW WIND AT 10 KNOTS OR LESS WITH A GENTLE SOUTHEAST SWELL COMPONENT WILL MAKE FOR GOOD BOATING CONDITIONS THIS AFTERNOON THROUGH SAT. WAVEWATCH AND LOCAL SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TODAY AND TONIGHT AND WINDS WILL GENERALLY NOT EXCEED ABOUT 10 OR 12 KNOTS FROM THE SOUTH TO SOUTHWEST THROUGH EARLY SATURDAY MORNING. LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/ AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND. THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DAG |
| #531517 (Received by flhurricane at: 1:56 PM 03.Aug.2012) AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 1248 PM CDT FRI AUG 3 2012 .AVIATION...VFR CONDITIONS WILL PREVAIL OUTSIDE OF ANY CONVECTION THROUGH THE REMAINDER OF THE AFTN AND EVNG HRS. BEST CHANCE FOR CONVECTION WILL BE ALONG THE ERN HALF OF THE CWA MAINLY TERMINALS EAST OF THE I-55 CORRIDOR. ONCE SHRA/TSRA DISSIPATE LOOK FOR VFR CONDITIONS THROUGH THE NIGHT. ONLY ISSUE COULD BE THE TYPICAL PROBLEM SITES THAT SEE MVFR VISBIES DURING THE EARLY MORNING HRS. /CAB/ $$ |
| #531516 (Received by flhurricane at: 1:56 PM 03.Aug.2012) AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 1247 PM CDT FRI AUG 3 2012 .AVIATION...A WEAK SHORT WAVE OFF THE COAST IS HELPING TO SET OFF A FEW SHOWERS IN AND AROUND LFT AND ARA. SHOULD NOT GET ANY WORSE THAN TEMPO MVFR IN SHOWERS FOR LFT. OTHERWISE VFR WITH HIGH PRESSURE TO THE EAST THAT WILL MAINTAIN A LIGHT SOUTHERLY FLOW. COULD SEE A FEW MORE SHOWERS AROUND DAYBREAK SATURDAY AND POSSIBLY A RUMBLE OF THUNDER AS THE SHORT WAVE MOVES SLOWLY NORTH. SWEENEY && .PREV DISCUSSION... /ISSUED 1037 AM CDT FRI AUG 3 2012/ DISCUSSION... CURRENT FORECAST IS GENERALLY ON TARGET. ONLY SIGNIFICANT CHANGE WAS TO START THE INHERITED SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS NOW RATHER THAN JUST CONFINE IT TO THE AFTERNOON HOURS...WITH ISOLATED ACTIVITY ALREADY EVIDENT ON RADAR OVER PARTS OF SOUTH CENTRAL LOUISIANA AND THE ADJACENT GULF WATERS. HEAT INDICES WILL NEAR 108 DEGREES IN SOME LOCATIONS THIS AFTERNOON...BUT DUE TO LIMITED AREAL EXTENT/TEMPORAL DURATION...WILL HOLD OFF ISSUING A HEAT ADVISORY AT THIS TIME. 13 PREV DISCUSSION... /ISSUED 726 AM CDT FRI AUG 3 2012/ DISCUSSION... FOR 12Z TAF ISSUANCE. AVIATION... ANOTHER DAY OF PERSISTENCE TERMINAL FORECASTS. UPPER RIDGE AXIS LINGERING OVER THE SRN PLAINS COULD ALLOW SOME CONVECTION TO DEVELOP PRIMARILY OVER THE ERN TERMINALS THIS AFTERNOON...BUT COVERAGE SHOULD REMAIN LOW SO REMOVED MENTION OF THUNDER FROM INHERITED KARA TAF. OTHERWISE SCATTERED CU SHOULD DEVELOP BY AFTERNOON BEFORE SEA BREEZE DEVELOPS AND SRLY WINDS PICK UP. 25 PREV DISCUSSION... /ISSUED 352 AM CDT FRI AUG 3 2012/ DISCUSSION... ONE MORE RELATIVELY QUIET WEATHER DAY...BEFORE RAIN CHANCE INCREASE FOR THIS WEEKEND. MID/UPPER LEVEL RIDGE IS EXPECTED TO SHIFT FURTHER WEST...ALLOWING SHORTWAVES ROTATING AROUND IT TO TRAVERSE OUR AREA...STARTING SATURDAY...AND CONTINUING TO AT LEAST MONDAY. BEYOND THAT...GOING WITH MORE TYPICAL LATE MORNING/AFTERNOON SHOWERS AND THUNDERSTORMS ASSOCIATED WITH SEA BREEZE. TEMPERATURE FORECASTS MAY BE MORE TRICKY DUE TO LOCATION AND TIMING OF SHOWERS AND THUNDERSTORMS THAT CAN CHANGE A MID 90S HIGH TO AN UPPER 80S READING...SO THERE IS SOME UNCERTAINTY IN THE MAX TEMPS THIS WEEK...BUT GOING WITH A NEAR NORMAL TO A DEGREE OR TWO ABOVE NORMAL. LOW TEMPS ALSO CAN BE INFLUENCED BY THE CONVECTION...BUT CLIMO LOWS IN THE MID AND UPPER 70S APPEAR REASONABLE. OF COURSE...ALSO MONITORING THE PROGRESS OF TROPICAL STORM ERNESTO...WHICH BEARS WATCHING FOR POSSIBLE GULF OF MEXICO ENTRANCE BY THE MIDDLE OF NEXT WEEK...IF IT CAN HOLD TOGETHER WITH AS MUCH SHEAR/DRY AIR IN ITS ENVIRONMENT TODAY. 15 && .PRELIMINARY POINT TEMPS/POPS... KLCH 93 79 93 77 93 / 10 10 20 20 30 KBPT 93 78 93 77 93 / 10 10 20 20 30 KAEX 96 75 96 75 95 / 20 10 20 20 50 KLFT 94 78 91 76 91 / 20 10 30 20 50 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ |
| #531514 (Received by flhurricane at: 1:56 PM 03.Aug.2012) AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 149 PM EDT FRI AUG 3 2012 .AVIATION...SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN TERMINALS ARE EXPECTED THIS AFTERNOON AS THE SEA BREEZE CONTINUES TO PUSH INLAND. AT THIS MOMENT...MOST OF THE ACTIVITY IS WEAKENING...BUT THE INTERACTION OF OUTFLOW BOUNDARIES COULD HELP IN THE DEVELOPMENT OF MORE THUNDERSTORMS. KEPT EASTERN TERMINALS EXCEPT KPBI WITH GUSTS UP TO 20 KTS AND TSRA UNTIL 03/1830Z...AFTER THAT EXPECT VCTS AND LIGHTER WINDS. WILL AMEND IF NECESARY. FOR KAPF...EXPECT ACTIVITY TO PUSH WEST TOWARDS THE TERMINAL BY 03/19Z THROUGH THE EVENING. A TROPICAL WAVE IS EXPECTED TO APPROACH THE AREA LATE TONIGHT...FOR THIS REASON EXPECT VCSH OVERNIGHT AND VCTS TO BEGIN AS EARLY AS 04/12Z. && .PREV DISCUSSION... /ISSUED 948 AM EDT FRI AUG 3 2012/ UPDATE... RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A WEAKNESS WITHIN THE RIDGE AXIS DUE TO AN UPPER TROUGH EXTENDING SOUTH FROM A WEAK UPPER LOW NEAR THE CAROLINA COAST. THE EARLY MORNING UPPER-AIR SOUNDING AT MIAMI INDICATED THIS WITH PRIMARILY WNW WINDS ALOFT. THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING NORTH-NORTHEAST OVER THE BAHAMAS WITH MOST OF THE SHOWER/TSTM COVERAGE REMAINING JUST EAST OF THE AXIS. THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS SURFACE TROUGH JUST EAST OF THE LOCAL AREA AND GENERALLY INDICATES IT CONTINUING WESTWARD OVER SOUTH FLORIDA THROUGH THE DAY SATURDAY. AS A RESULT...WILL LIKELY SLIGHTLY ADJUST THE RAINFALL CHANCES UP THROUGH THIS TIME SATURDAY IN THE AFTERNOON FORECAST PACKAGE. OTHERWISE...NO CHANGES WERE NECESSARY TO THE PREVIOUS PACKAGE. 85/AG PREV DISCUSSION... /ISSUED 724 AM EDT FRI AUG 3 2012/ AVIATION...VFR WILL PREVAIL UNTIL SCATTERED TSRA DEVELOPS THIS AFTERNOON. SO HAVE VCTS ALL SITES. MORNING SHOWERS COULD MOVE ONSHORE THE ATLANTIC COAST THIS MORNING. MVFR OR IFR IS POSSIBLE WITH THE AFTERNOON TSRA, BUT THOSE CONDITIONS WOULD BE BRIEF. LIGHT WINDS WILL BECOME ONSHORE NEAR 10 KT THIS AFTERNOON. DG/KOB PREV DISCUSSION... /ISSUED 359 AM EDT FRI AUG 3 2012/ LONG TERM...MONDAY THROUGH THURSDAY...THE CHANCE OF RAIN TAPERS DOWNWARD FROM MIDWEEK ON AS THE ATLC HIGH CENTER MOVES WESTWARD PULLING SOME DRIER AIR OVER S FLA. A DEEP EASTERLY WIND FLOW DICTATES THAT THE HIGHER POPS WILL BE IN THE W INTERIOR AND W COAST AS HURRICANE ERNESTO APPROACHES THE YUCATAN PENINSULA BY MID WEEK. AS ERNESTO TRACKS WESTWARD...AT THIS TIME...THE ONLY EFFECT TO S FLA WILL BE AN INCREASE IN THE LOW LEVEL EASTERLY WINDS FROM MIDWEEK ON. BUT KEEP AWARE OF NHC FORECASTS OF THE DEVELOPMENT AND FORECAST MOVEMENT OF THIS STORM. MARINE...AT THIS TIME...EASTERLY WINDS WILL BE BELOW 15 KNOTS WITH SEAS 3 FEET OR LESS TODAY AND THROUGH THE WEEKEND. WINDS AND SEAS WILL BEGIN TO INCREASE EARLY NEXT WEEK BUT AT THIS TIME NO HIGHLIGHTS ARE EXPECTED. FIRE WEATHER...NO CONCERNS AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 79 89 77 88 / 30 50 40 40 FORT LAUDERDALE 79 89 79 88 / 30 50 40 40 MIAMI 78 90 79 89 / 30 50 40 40 NAPLES 77 91 77 89 / 20 50 40 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ |
| #531515 (Received by flhurricane at: 1:56 PM 03.Aug.2012) AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 147 PM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TODAY WITH POSSIBLE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN FOR SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE: 17Z SFC ANALYSIS HAD THE COLD FRONT PUSHING ACROSS QUEBEC WITH GYX/CANADIAN RADARS INDICATING SOME SHOWERS/TSTMS DEVELOPING ACROSS THE NORTHERN AND WESTERN AREAS AHEAD OF THE BOUNDARY. STILL LOOKING FOR SOME STORMS TO BE STRONG W/VERY HEAVY RAINFALL AND STRONG WIND GUSTS. INCLUDED NORTHERN PISCATAQUIS AND NE AROOSTOOK COUNTY IN THE LATEST HWO FOR STRONG TSTMS. ACTIVITY SHOULD WIND DOWN BY EVENING AS FRONT MOVES EAST AND BEST INSTABILITY SHIFTS EAST. JUST ABOUT EVERYWHERE HAS HIT THE CONVECTIVE TEMPERATURE. MID LEVEL LAPSE RATES FROM SPC MESO-ANALYSIS PAGE INDICATE 6.0 TO 6.5C/KM ACROSS THE NORTH-CENTRAL AND DOWEAST REGIONS. SBCAPES HITTING 2000 JOULES IN THESE AREAS AS WELL SO BUOYANCY IS THERE. TWEAKED QPF USING NERFC AND GFS AND THEN ADJUSTED MANUALLY. PREVIOUS DISCUSSION... MAIN FOCUS FOR TODAY WILL BE ON THE NEXT...SOMEWHAT STRONGER COLD FRONT WHICH CURRENTLY XTNDS NE-SW FROM CENTRAL QUEBEC DOWN INTO THE ERN GRT LAKES AND IS STILL EXPECTED TO SWING SEWRD ACROSS THE REGION LATER TODAY. SFC CONVERGENCE ALONG AND IN ADVANCE OF THIS BNDRY WILL INTERACT W/ TDS IN THE MID TO UPPER 60S AND A HEALTHY UPPER SHORT WAVE TO TRIGGER THE THREAT OF SOME CONVECTION ACROSS THE AREA BY LATE AM INTO THE AFTN W/ ACTIVITY WINDING DOWN FROM NW-SE LATER THIS AFTN AS DRIER AIR BEGINS TO WORK INTO THE REGION. WHILE SHEAR VALS NOT VERY IMPRESSIVE...SFC BASED CAPES JUMP UP NR 2000 J/KG ACROSS CENTRAL/E CENTRAL AREAS BY ERLY AFTN SO EXPECT THE THREAT OF AN ISOLD STRONG TO SVR TSTM CAN NOT BE RULED OUT AND WILL CONT ENHANCED WORDING... SIMILAR TO THE LAST FEW DYS...ANY ERLY AM FOG/STRATUS TODAY SHOULD LIFT/BURN OFF RATHER QUICKLY THIS AM W/ OUR COASTAL AREAS BEING THE SLOWEST TO IMPROVE. A MORE SWRLY LOW-LEVEL FLOW SHOULD ALLOW HIGH TEMPS TO REACH THE LOWER TO MID 80S N AND MID TO UPPER 80S S AWAY FROM THE COAST... WHILE DRIER AIR OVERSPREADS THE AREA FROM NW-SE TNGT...CLRG SKIES AND LGT WINDS WILL ALLOW FOR SIGNIFICANT COOLING LIKELY ALLOWING TEMPS TO REACH TDS AND INCREASING THE POTENTIAL FOR SOME FOG AGAIN TNGT. IN THESE SCENARIOS IT IS ALWAYS A RACE BTWN THE DRYING AND COOLING AND WHICH FACTOR WINS OUT. FOR NOW...WILL CARRY PATCHY FOG N AND CENTRAL W/ AREAS DOWNEAST AS THESE WILL BE THE LAST TO SEE THE DRIER AIR... EXPECT LOWS TNGT TO BE SIGNIFICANTLY COOLER THAN THE LAST FEW DYS...AT LEAST FOR OUR CENTRAL AND NRN AREAS W/ LOWS RANGING FROM THE LOWER TO MID 50S N TO THE LOWERS 60S S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... EXPECT THE WEEKEND TO BE MAINLY DRY WITH ABOVE NORMAL TEMPERATURES AS HIGH PRESSURE BUILDS OVER THE REGION. SATURDAY WILL START OUT MOSTLY SUNNY, BUT CLOUDS WILL INCREASE FROM THE SOUTH LATE IN THE DAY AS A WARM FRONT LIFTS NORTHWARD. THIS BOUNDARY WILL MOVE ACROSS THE STATE SATURDAY NIGHT AND MAY PRODUCE A FEW SHOWERS OVER THE HIGHER TERRAIN AS IT DOES SO. MUGGIER AIR WILL SPREAD INTO THE REGION BEHIND THE FRONT WITH A RETURN OF MID 60S DEWPOINTS BY SUNDAY AFTERNOON. A COLD FRONT WILL APPROACH THE REGION FROM QUEBEC SUNDAY AFTERNOON, BUT MOST OF THE PRECIPITATION WILL HOLD OFF UNTIL LATE IN THE DAY, EXCEPT PERHAPS IN FAR WESTERN AREAS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE AFOREMENTIONED COLD FRONT WILL MOVE THROUGH THE STATE LATE SUNDAY NIGHT INTO MONDAY MORNING. THE TIMING OF THE FRONTAL PASSAGE IS NOT OPTIMAL FOR INSTABILITY, THOUGH 0-6 KM SHEAR INCREASES TO AROUND 30 KT JUST AHEAD OF THE FRONT. DOWNEAST AREAS WOULD HAVE THE BEST CHANCES OF SEEING ANY ORGANIZED CONVECTION, AS STORMS WOULD MOST LIKELY BE ELEVATED ACROSS THE NORTH. ALSO OF CONCERN IS INCREASING MOISTURE TRANSPORT AHEAD OF THE FRONT; MODELS ARE INDICATING PWATS OF 2+ INCHES AREAWIDE SUNDAY NIGHT INTO MONDAY MORNING. IN ADDITION, THE WARM CLOUD LAYER LOOKS TO BE DEEP, AROUND 13-14 KFT. THIS MEANS THAT ANY STORMS WOULD BE CAPABLE OF PRODUCING HEAVY RAIN. ONCE THE FRONT GOES BY, HIGH PRESSURE AND DRIER WEATHER RETURNS MONDAY NIGHT AND TUESDAY. THEN ANOTHER COLD FRONT WILL GRADUALLY MOVE SOUTH TUESDAY NIGHT, BECOMING NEARLY STATIONARY NEAR THE SAINT JOHN VALLEY WEDNESDAY BEFORE FINALLY PUSHING SOUTH INTO DOWNEAST MAINE WEDNESDAY NIGHT/THURSDAY. THE LONGER-TERM MODELS ARE SHOWING SOME DIFFERENCES IN TIMING OF THIS FEATURE AND ITS ASSOCIATED PRECIPITATION, SO HAVE STUCK WITH 20-30 POPS FOR MID WEEK. TEMPERATURES WILL BE SEASONABLE THROUGH THE WEEK. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... NEAR TERM: ALL TAF SITES IFR ATTM XCPT KPQI WHICH IS CURRENTLY MVFR. THIS RATHER IRONIC CONSIDERING A TSTM DROPPED SIGNIFICANT RAINFALL ON PQI THU AFTN WHERE MOST OTHER AREAS SO LITTLE OR NO RAINFALL... IN ANY CASE...THINK KPQI WILL JOIN THE REST SHORTLY. IFR CONDS SHOULD THEN PERSIST INTO THE AM HRS SIMILAR TO LAST SEVERAL DAYS W/ KBHB NEAR THE SRN COAST THE SLOWEST TO IMPROVE. DESPITE THE PASSAGE OF A COLD FRONT LATER TODAY AND THE INFLUX OF LOWER TDS...LGT WINDS BEHIND THE FRONT TNGT AND CLR SKIES WILL LEAD TO GOOD COOLING AND WILL LIKELY RESULT IN PATCHY FOG ACROSS THE NRN TAF SITES W/ MORE WDSPRD FOG S... SHORT TERM: VFR IS EXPECTED THROUGH THE WEEKEND, WITH EXCEPTION OF IFR DUE TO PATCHY FOG LATE SATURDAY NIGHT, ESPECIALLY AT THE TERMINALS. A COLD FRONT WILL MOVE ACROSS THE AREA EARLY MONDAY, PRODUCING SHOWERS AND THUNDERSTORMS. WHILE VFR SHOULD PREVAIL THROUGH MIDWEEK, MVFR CONDITIONS ARE POSSIBLE IN ANY PRECIPITATION SUNDAY NIGHT AND MONDAY. && .MARINE... NEAR TERM: WINDS/SEAS SHOULD REMAIN BLO SCA LEVELS THRU TNGT. FOG WILL CONT TO BE AN ISSUE THRU TNGT. SHORT TERM: A SMALL CRAFT ADVISORY MAY BE NEEDED LATE SUNDAY THROUGH MONDAY AS SOUTH WINDS INCREASE AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL BE BORDERLINE /GUSTS AROUND 20 KT/ BUT WAVES LOOK TO REACH 5-6 FT LATE SUNDAY EVENING AND REMAIN SO INTO EARLY MONDAY NIGHT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT |
| #531511 (Received by flhurricane at: 1:29 PM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 124 PM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...ONLY CHANGE AT THIS TIME WAS TO BUMP POPS UP ALONG A STRIPE OF REAL ESTATE ROUGHLY FOLLOWING THE COAST AND ABOUT 20 MILES INLAND. THERE IS SOME MODEL AGREEMENT THAT THIS WILL BE WHERE CONVECTION FIRES THIS AFTERNOON. THE UPPER LOW WILL PROVIDE COOL AIR ALOFT AND SOME MID LEVEL INSTABILITY BUT NOT REALLY ANY FORCING TO MENTION SINCE IT WILL BARELY BE MOVING. STORM INITIATION THUS SEEMS TO MAINLY BE DRIVEN BY LOW LEVEL PROCESSES WHICH IN THIS CASE WILL BE NOT ONLY THE SEABREEZE BUT ALSO SOME DIFFERENTIAL HEATING ON THE EAST SIDE OF A CLOUD MASS NOW SEE OVER INLAND NC ZONES. SLIGHT CHANCE POPS WILL REMAIN ELSEWHERE DUE TO THE SLIGHTLY COOL MID LEVELS AND ALSO THE PRESENCE OF SOME HARD-TO-DETECT OUTFLOW BOUNDARIES FROM YESTERDAYS CONVECTION. PREVIOUS DISCUSSION: AS OF 700 AM FRIDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA WITH POSSIBLE THUNDER...OVER INLAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE CONTINUED DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND THE MID LEVEL DYNAMICS FROM THE VORT...WILL ALL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 12Z...ISOLATED TO SCATTERED STORMS HAVE FORMED ALONG THE SEA BREEZE NEAR ILM AND TO THE WEST OF CRE AND MYR. CONVECTIVE POTENTIAL AT THESE SITES PRESENTLY AT ITS HIGHEST WITH THE FOCUS SHIFTING WESTWARD AS THE AFTERNOON PROGRESSES. HAVING SAID THAT...THE PROBABILITY AT EACH SITE IS LOW ENOUGH THAT INCLUSION IN THE TAFS IS NOT WARRANTED. PILOTS NAVIGATING TO AREA TERMINALS ARE LIKELY TO ENCOUNTER CONVECTION ENROUTE THOUGH. AFTER SUNSET...STORMS SHOULD WANE AND THE REMAINDER OF THE TAF PERIOD IS EXPECTED TO BE VFR. LIGHT AND VARIABLE WINDS ARE EXPECTED AFTER SUNSET WITH DAYLIGHT WINDS DURING THE PERIOD EXPECTED TO BE S-SE INVOF 10KT. EXTENDED OUTLOOK...PREDOMINANTLY VFR BUT THERE IS A CHANCE OF MORNING MVFR VSBYS IN BR AND A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...NO CHANGES AT ALL AT THIS TIME. AS OF 700 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WIND DIRECTIONS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531508 (Received by flhurricane at: 1:24 PM 03.Aug.2012) AFDBRO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 1220 PM CDT FRI AUG 3 2012 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...GUSTY SOUTHEAST WINDS AT 20 TO 25 KNOTS ARE EXPECTED THROUGH THIS EVENING...UP TO 3 OR 4Z BEFORE DIMINISHING TO AROUND 10 KNOTS. A FEW CLOUDS IN THE 2500 FOOT RANGE WILL BE POSSIBLE TONIGHT...BUT PREDOMINANT VFR CONDITIONS ARE EXPECTED. WINDS ARE EXPECTED TO BE A LITTLE LIGHTER ON SATURDAY...WITH GUSTS IN THE 17 TO 22 KNOT RANGE FROM THE SOUTHEAST. /68-JGG/ && .PREV DISCUSSION... /ISSUED 618 AM CDT FRI AUG 3 2012/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...VFR CONDITIONS TO PREVAIL THE NEXT 24 HOURS AS HIGH PRESSURE AT THE SURFACE AND ALOFT MAINTAIN SUBSIDENCE ACROSS ALL OF SOUTH TEXAS. MAIN CUMULUS FIELD TO EXTEND ALONG AND EAST OF HIGHWAY 281. A LOCAL PRESSURE GRADIENT WILL ALLOW FOR THE SOUTHEAST WINDS TO BECOME GUSTY DURING THE AFTERNOON WITH SOME GUSTY PERIODS OF 20 TO 25 KNOTS BETWEEN 18Z TODAY AND 03Z SATURDAY. PREV DISCUSSION... /ISSUED 518 AM CDT FRI AUG 3 2012/ DISCUSSION...AN ERROR OCCURED DURING SOME PROCEDURE CHECK OF THE GRIDS BEFORE ISSUANCE OF EARLIER FORECAST PACKAGE. HIGH TEMPERATURES ON SATURDAY WHERE SOMEHOW LOWERED BY 2 TO 5 DEGREES OVER WHAT THEY SHOULD DEPICT. A CORRECTED VERSION IS OUT AND THE TEMP/POP TABLE BELOW HAS BEEN UPDATED. WE APOLOGIZE FOR ANY FOR ANY INCONVENIENCE THAT THIS MAY HAVE OCCURRED. PREV DISCUSSION... /ISSUED 345 AM CDT FRI AUG 3 2012/ SHORT TERM /TODAY THROUGH SATURDAY/...LATEST MODEL PACKAGE SHOWS LITTLE CHANGE IN UPPER RIDGE STRUCTURE OVER THE NEXT 36 HOURS. THE CENTER OF THE DEEP LAYERED RIDGE TO REMAIN OVER NORTH CENTRAL TO NORTHWEST TEXAS MAINTAINING STRONG SUBSIDENCE AIR ACROSS SOUTH TEXAS. PLENTY OF HEAT AND DRY AIR TO REMAIN IN PLACE TODAY AND SATURDAY WITH LITTLE TO NO RAIN EXPECTED. ANY ADDED MOISTURE ON SATURDAY IS NOT LIKELY TO KICK OFF ANYTHING MORE THEN ONE OR TWO SHOWERS OR THUNDERSTORMS. WARM AIR ALOFT TO MAINTAIN A CAP. INVERTED TROUGH THAT HAS BEEN TALKED ABOUT HAS BECOME STRETCHED OUT AND WEAKER AND STRONGER THEN USUAL SOUTH WINDS ARE NOT CONDUCIVE FOR AN ACTIVE SEA BREEZE. WITH THIS SAID...LOWERED SATURDAY POPS BELOW 20 PERCENT WITH KENEDY COUNTY THE BEST AREA TO SEE ISOLATED CONVECTION. TEMPERATURES TO REMAIN WELL ABOVE NORMAL WITH GOING FORECAST REMAINING ABOVE ALL GUIDANCE VALUES. SOUTHEAST WINDS TO INCREASE FRIDAY AND SATURDAY AFTERNOON WITH INLAND AREAS SEEING GUSTS BETWEEN 25 TO 30 MPH. LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...PATTERN SHIFT NEXT WEEK STILL EXPECTED TO BRING SOME CHANGES TO THE STAGNANT DOLDRUMS THAT HAVE BEEN THE PAST WEEK. THE UPPER RIDGE WILL SHIFT WESTWARD TO THE FOUR CORNERS REGION STARTING SUNDAY...TAKING THE CORE OF THE SUBSIDENCE WITH IT. AN INVERTED TROUGH WILL SHARPEN ACROSS THE SOUTHEASTERN US AND CHASE THE RIDGE WESTWARD ACROSS THE NORTHERN GULF. THIS WILL INTRODUCE DEEPER MOISTURE. THIS MOISTURE AND INSTABILITY FROM THE TROUGH WILL ALLOW THE SEABREEZE TO ACTIVATE EACH DAY AND PERSIST THROUGH THE WEEK. TEMPERATURES WILL REMAIN ABOVE NORMAL...BUT WILL BE HELD DOWN SLIGHTLY DUE TO DEEPER MOISTURE IN THE REGION. AS THE RIDGE MOVES WEST...THE HEAT LOW THAT HAS PERSISTED IN NORTH TEXAS WILL ALSO DEPART...ALLOWING WINDS TO SLACKEN FOR MOST OF THE WEEK. MARINE...NOW THROUGH SATURDAY...LOCAL PRESSURE GRADIENT WILL CONTINUE TO PRODUCE SMALL CRAFT EXERCISE CAUTION WINDS MAINLY OVER THE OPEN GULF DURING THE OVERNIGHT HOURS AND ACROSS THE LAGUNA DURING THE LATE MORNING AND AFTERNOON HOURS. A FEW AREAS NEAR PORT MANSFIELD COULD SEE INTERMITTENT SMALL CRAFT ADVISORY CONDITIONS BUT DURATION IS NOT LIKELY TO BE LONG ENOUGH TO WARRANT AN ADVISORY AT THIS TIME. SEAS CONSIST OF MAINLY WIND WAVES WHICH WILL FLUCTUATE 1 TO 3 FEET DURING THE DAY AND 3 TO 5 FEET OVERNIGHT. SATURDAY NIGHT THROUGH WEDNESDAY...LOW PRESSURE THAT HAS BEEN MEANDERING ACROSS NORTH TEXAS WILL WEAKEN AND SHIFT FURTHER WEST FOR THE EXTENDED PERIOD...ALLOWING WINDS TO SLACKEN TO AROUND 10 KNOTS. THIS WILL BRING LIGHTER SEAS 3 FEET OR LESS FOR THE FORECAST PERIOD. SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE EACH DAY DUE TO INSTABILITY ALOFT AND DEEPER MOISTURE. FIRE WEATHER...ENHANCED FIRE DANGER CONDITIONS WILL BE POSSIBLE MAINLY FROM 281 WESTWARD TODAY AND SATURDAY AFTERNOON. DRY AIR LOFT TO MIX DOWN TO THE SURFACE WITH DEW POINTS AND RELATIVE HUMIDITY VALUES TO FALL RAPIDLY THROUGH THE AFTERNOON. RH VALUES TO DROP BETWEEN 20 AND 30 PERCENT AND POSSIBLY BELOW 20 PERCENT IN ZAPATA, STARR AND JIM HOGG COUNTIES. 20FT WINDS ARE EXPECTED TO BE BELOW CRITICAL FIRE DANGER LEVELS...BUT CRITICAL GROWTH CONDITIONS ARE WARRANTED AS GUSTS RANGE FROM 20 TO 25 MPH LATE IN THE AFTERNOON AND VEGETATION REMAINS VERY DRY. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531506 (Received by flhurricane at: 1:15 PM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1247 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHENS OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARM TO HOT TEMPS...HIGH DEW POINTS IN THE 70S HAVE RESULTED IN SFC BASED CAPES AROUND 3 TO 4 J/KG ACROSS LONG ISLAND. ISOLATED SHOWERS AND TSTMS COULD CONTINUE TO FORM ON THE SEA BREEZE BOUNDARY...AND THE MAIN FORMATION SHOULD BE ACROSS THE INTERIOR AS THE AFTERNOON PROGRESSES. THE OTHER TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA. HEAT INDEX VALUES ALREADY AROUND 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. TEMPS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD WITH VFR EXPECTED. THE ONLY EXCEPTION WILL BE SOME EARLY MORNING MVFR OR IFR FOG. ANY SUB-VFR CIGS ARE EXPECTED TO IMPROVE TO VFR BY 13Z-15Z. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IN THE TAFS. WINDS ARE GENERALLY SW UNDER 10 KT THROUGH THE PERIOD. DURING THE AFTERNOON...SEA BREEZES ARE EXPECTED TO SHIFT WINDS MORE SOUTHERLY AND INCREASE SLIGHTLY. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS MORNING OR EARLY THIS AFTERNOON FOR TIMING OF SEABREEZE. OUTLOOK FOR 12Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS....MAINLY IN THE AFTERNOON. LATE DAY TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...NV/DW |
| #531505 (Received by flhurricane at: 1:14 PM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 1256 PM EDT FRI AUG 3 2012 .SYNOPSIS... AN APPROACHING COLD FRONT WILL STALL OVER THE REGION TONIGHT...BRINGING A CHANCE FOR SHOWERS AND THUNDERSTORMS. HOT AND HUMID CONDITIONS WILL CONTINUE TOMORROW AND SUNDAY. A STRONGER COLD FRONT WILL CROSS THE REGION LATE SUNDAY NIGHT OR MONDAY BRINGING ADDITIONAL SHOWERS AND THUNDERSTORMS TO THE AREA. HIGH PRESSURE BUILDS OVER THE REGION MONDAY THROUGH WEDNESDAY WITH DRIER CONDITIONS EXPECTED. && .NEAR TERM /THROUGH TONIGHT/... WEAK FRONTAL BOUNDARY APPROACHING THE CWA THIS AFTERNOON FROM THE NORTHWEST. VISIBLE SATELLITE IMAGERY SHOWS DECENT CLEARING ACROSS MOST OF THE FORECAST AREA. MODIFIED 12Z KGYX SOUNDING INDICATES UPWARDS OF 2500J/KG WORTH OF CAPE TO WORK WITH. ALTHOUGH SHEAR IS WEAK...EXPECT SOME SCATTERED STORMS TO DEVELOP THIS AFTERNOON AND EVENING. SOME MAY BE STRONG ENOUGH TO REACH SEVERE LIMITS...BUT THEY SHOULD BE PRETTY ISOLATED. ONCE DIURNAL HEATING FADES CONVECTION SHOULD DIE OFF PRETTY QUICKLY. WITH DEWPOINTS STILL WELL INTO THE 60S...EXPECT FOG TO SET UP AGAIN ACROSS MUCH OF THE AREA. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... FOG AND STRATUS SHOULD BURN OFF DURING THE MORNING HOURS TOMORROW. FRONTAL BOUNDARY STALLED TO OUR SOUTH WILL START TO MAKE ITS WAY NORTHWARD AS A WEAK WARM FRONT. NOT MUCH LEFT IN THE WAY OF DYNAMICS WITH THE BOUNDARY AND SHOWERS AND THUNDERSTORMS MAY BE LIMITED TO WESTERN PORTIONS OF CWA AND THE MOUNTAINS. EXPECT CLEARING GOING INTO SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A WARM AND VERY MOIST AIRMASS WILL BE TRANSPORTED NORTHWARD INTO NORTHERN NEW ENGLAND SATURDAY NIGHT THROUGH SUNDAY NIGHT AS THE AREA WILL BE SANDWICHED IN BETWEEN A LARGE HIGH PRESSURE SYSTEM OVER THE WESTERN ATLC AND AN APPROACHING COLD FRONT FROM THE WEST. THIS MAY MEAN A DECENT AMOUNT OF FOG/HAZE AND STRATUS SATURDAY NIGHT AND SUNDAY NIGHT. DEWPOINTS WILL PROBABLY REACH THE 70-75F RANGE SOMETIME SUNDAY AND SUNDAY NIGHT WHICH WILL MAKE IT VERY MUGGY. AS FAR AS POPS GO...LOOKS MAINLY DRY SATURDAY NIGHT AND SUNDAY ALTHOUGH A FEW THUNDERSTORMS MAY START IMPINGING ON THE AREA LATER SUNDAY AFTERNOON...ESPECIALLY IN NH. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS APPEARS TO BE SUNDAY NIGHT AND MONDAY MORNING WHEN THE SHORT WAVE AND COLD FRONTAL FORCING APPROACHES AND SUBSEQUENTLY MOVES ON THROUGH. THESE THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE VERY HEAVY RAINFALL RATES DUE TO THE VERY MOIST COLUMN. CAN/T RULE OUT A FEW STRONG STORMS AS WELL...ESPECIALLY IN TERMS OF WIND DESPITE BEST FORCING APPROACHING AT NIGHT. FRONT LOOKS TO MOVE OFFSHORE MONDAY WITH THE BEST CHANCE OF SHOWERS AND STORMS BEING IN THE MORNING. HOWEVER...WOULDN/T BE SURPRISED TO SEE THE FRONT ACTUALLY COME THROUGH SLOWER THAN CURRENTLY PROGGED...WHICH COULD MEAN HIGHER POPS MONDAY AFTERNOON AND LESSER POPS SUNDAY NIGHT. THEREAFTER...FAIR AND DRIER WEATHER IS EXPECTED INTO MIDWEEK. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM...EXPECT VFR CONDITIONS TO DETERIORATE TONIGHT TO IFR/LIFR CONDITIONS IN FOG. FOG WILL LIFT BY MID-MORNING TOMORROW WITH VFR CONDITIONS RETURNING AND REMAINING IN PLACE FOR THE REMAINDER OF THE SHORT TERM PERIOD. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...LOCAL IFR CONDITIONS POSSIBLE IN STRATUS AND FOG SATURDAY NIGHT THROUGH MONDAY MORNING AS VERY MOIST AIRMASS SITS ACROSS THE AREA. BEST CHANCE OF LOW CIGS AND VSBYS WILL BE AT NIGHT. SHOWERS AND STORMS A GOOD BET SUNDAY NIGHT AND MONDAY MORNING. THEREAFTER...CIGS AND VSBYS LOOK TO IMPROVE. && .MARINE... SHORT TERM /THROUGH SATURDAY...NO FLAGS EXPECTED. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...COLD FRONT WILL APPROACH THE WATERS FROM THE WEST SUNDAY NIGHT AND CROSS MONDAY. AHEAD OF THE FRONT...A LONG SOUTHERLY FETCH OF WIND MAY BRING SEAS UP TO SCA LEVELS BY LATER SUNDAY AFTERNOON WHICH COULD LAST THROUGH MONDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ |
| #531503 (Received by flhurricane at: 12:47 PM 03.Aug.2012) AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 1037 AM CDT FRI AUG 3 2012 .DISCUSSION... CURRENT FORECAST IS GENERALLY ON TARGET. ONLY SIGNIFICANT CHANGE WAS TO START THE INHERITED SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS NOW RATHER THAN JUST CONFINE IT TO THE AFTERNOON HOURS...WITH ISOLATED ACTIVITY ALREADY EVIDENT ON RADAR OVER PARTS OF SOUTH CENTRAL LOUISIANA AND THE ADJACENT GULF WATERS. HEAT INDICES WILL NEAR 108 DEGREES IN SOME LOCATIONS THIS AFTERNOON...BUT DUE TO LIMITED AREAL EXTENT/TEMPORAL DURATION...WILL HOLD OFF ISSUING A HEAT ADVISORY AT THIS TIME. 13 && .PREV DISCUSSION... /ISSUED 726 AM CDT FRI AUG 3 2012/ DISCUSSION... FOR 12Z TAF ISSUANCE. AVIATION... ANOTHER DAY OF PERSISTENCE TERMINAL FORECASTS. UPPER RIDGE AXIS LINGERING OVER THE SRN PLAINS COULD ALLOW SOME CONVECTION TO DEVELOP PRIMARILY OVER THE ERN TERMINALS THIS AFTERNOON...BUT COVERAGE SHOULD REMAIN LOW SO REMOVED MENTION OF THUNDER FROM INHERITED KARA TAF. OTHERWISE SCATTERED CU SHOULD DEVELOP BY AFTERNOON BEFORE SEA BREEZE DEVELOPS AND SRLY WINDS PICK UP. 25 PREV DISCUSSION... /ISSUED 352 AM CDT FRI AUG 3 2012/ DISCUSSION... ONE MORE RELATIVELY QUIET WEATHER DAY...BEFORE RAIN CHANCE INCREASE FOR THIS WEEKEND. MID/UPPER LEVEL RIDGE IS EXPECTED TO SHIFT FURTHER WEST...ALLOWING SHORTWAVES ROTATING AROUND IT TO TRAVERSE OUR AREA...STARTING SATURDAY...AND CONTINUING TO AT LEAST MONDAY. BEYOND THAT...GOING WITH MORE TYPICAL LATE MORNING/AFTERNOON SHOWERS AND THUNDERSTORMS ASSOCIATED WITH SEA BREEZE. TEMPERATURE FORECASTS MAY BE MORE TRICKY DUE TO LOCATION AND TIMING OF SHOWERS AND THUNDERSTORMS THAT CAN CHANGE A MID 90S HIGH TO AN UPPER 80S READING...SO THERE IS SOME UNCERTAINTY IN THE MAX TEMPS THIS WEEK...BUT GOING WITH A NEAR NORMAL TO A DEGREE OR TWO ABOVE NORMAL. LOW TEMPS ALSO CAN BE INFLUENCED BY THE CONVECTION...BUT CLIMO LOWS IN THE MID AND UPPER 70S APPEAR REASONABLE. OF COURSE...ALSO MONITORING THE PROGRESS OF TROPICAL STORM ERNESTO...WHICH BEARS WATCHING FOR POSSIBLE GULF OF MEXICO ENTRANCE BY THE MIDDLE OF NEXT WEEK...IF IT CAN HOLD TOGETHER WITH AS MUCH SHEAR/DRY AIR IN ITS ENVIRONMENT TODAY. && .PRELIMINARY POINT TEMPS/POPS... KLCH 94 78 93 77 / 10 10 20 20 KBPT 93 78 93 77 / 10 10 20 20 KAEX 96 75 96 75 / 20 10 20 20 KLFT 94 78 91 76 / 20 10 30 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ |
| #531502 (Received by flhurricane at: 12:35 PM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1216 PM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... SHORTWAVE TROUGH LOCATED NORTHERN KY/SOUTHERN OH WITH STATIONARY FRONT LOCATED WESTERN VA STRETCHING BACK ACROSS MIDWEST. WEAK UPPER LEVEL LOW CURRENTLY OVER EASTERN NC. SFC HIGH PRESSURE/SOUTHERLY FLOW WILL REINFORCE WARM/HUMID AIRMASS ACROSS THE REGION THIS AFTERNOON RESULTING IN AFTERNOON AND EARLY EVENING SHOWERS/THUNDERSTORMS. STARTING TO SEE SOME CU DEVELOPING ACROSS CENTRAL/WESTERN VA ALREADY. LATEST KWAL SOUNDING DEPICTS PRECIP WATERS AROUND 1.4 INCHES WITH MUCH LESS INSTABILITY THAN YESTERDAY...CAPE VALUES 1500-2000 J/KG AND LI -3 TO -5. TEMPERATURES IN THE 600MB TO 400MB LAYER HAVE WARMED 3-5C OVER THE PAST 24 HRS. LATEST KLWX SOUNDING MORE UNSTABLE WITH BETTER PRECIP WATERS AND LAPSE RATES. LATEST HI RES MODELS/SREF INITIATE CONVECTION IN EASTERN NC NEAR SHORTWAVE/VORT MAX AND LIFT PRECIP NORTHEAST. OUTFLOWS FROM CONVECTION WILL SPREAD SHOWERS/THUNDERSTORMS EWD TOWARD WARM AND UNSTABLE AIRMASS IN PLACE ACROSS CENTRAL VA. HAVE OPTED TO PLACE SCATTERED POPS FROM THE BAY WWD WITH ISOLATED POPS BAY EWD. LATEST MET/MAV GUIDANCE WELL BELOW CLIMO WITH POPS IN THE 10 TO 15 PCT RANGE SO SOME UNCERTAINTY EXISTS. WILL CONTINUE TO WATCH HOW CU FIELD EVOLVES AND ADJUST POPS ACCORDINGLY. CURRENT TEMPS RUNNING 2 TO 4 DEGS BELOW 24 HOURS AGO DUE TO YESTERDAY AFTERNOON/EVENING RAINFALL AND COOLER OVERNIGHT TEMPERATURES. HOWEVER...SOUTHERLY FLOW AND HEIGHT/THICKNESS VALUE INCREASES WILL RESULT IN AFTERNOON TEMPERATURES UPPER 80S TO LOW/MID 90S WITH HEAT INDEX VALUES MID/UPPER 90S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 8-10KT TODAY. THE SKY SHOULD BE MOSTLY SUNNY THIS MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531501 (Received by flhurricane at: 12:33 PM 03.Aug.2012) AFDSJU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1219 PM AST FRI AUG 3 2012 .UPDATE...A FAIR WEATHER PATTERN WILL DOMINATE THE LOCAL AREA THIS AFTERNOON...AS HIGH PRESSURE RIDGE AND SUBSIDENCE ASSOCIATED WITH TS ERNESTO DOMINATE THE LOCAL WEATHER CONDITIONS. AS A RESULT...EXPECT PARTLY CLOUDY SKIES AND MINIMAL SHOWER ACTIVITY FOR THE NEXT COUPLE OF HOURS. ON THE OFFICIAL FORECAST TRACK...TROPICAL STORM ERNESTO WILL BE MAKING ITS CLOSEST APPROACH TO SAINT CROIX LATE THIS EVENING. AT THIS TIME...IMPACTS FROM THIS SYSTEM CONTINUE TO BE ROUGH SEAS ACROSS THE CARIBBEAN WATERS AND SOME OUTER RAINBANDS THAT MAY REACH PARTS OF THE LOCAL ISLANDS TONIGHT THROUGH SATURDAY EVENING... BRINGING GUSTY WINDS AND LOCALLY HEAVY RAINFALL. && .AVIATION...PREVAILING VFR CONDITIONS WILL CONTINUE. LLVL WINDS WILL REMAIN FROM THE NORTHEAST THRU TONIGHT... VEERING FROM THE EAST TO SOUTHEAST EARLY SATURDAY THRU SUNDAY. SUSTAIN WINDS OF 15 TO 25 KTS WITH HIGHER GUSTS UP TO 40 KTS ARE POSSIBLE DURING THE WEEKEND AS TS ERNESTO MOVES SOUTH OF THE FA. OUTER BANDS OF TS ERNESTO MAY AFFECT THE ISLANDS BTWN 04/06Z AND 05/12Z. && .PREV DISCUSSION... /ISSUED 614 AM AST FRI AUG 3 2012/ SYNOPSIS...AT 5 AM AST...TROPICAL STORM ERNESTO WAS LOCATED NEAR LATITUDE 13.5 NORTH...LONGITUDE 60.7 WEST AND WAS MOVING TOWARD THE WEST AT NEAR 24 MPH. ERNESTO IS EXPECTED TO MOVE GENERALLY WEST FOR THE NEXT COUPLE OF DAYS...WITH A GRADUAL DECREASE IN FORWARD SPEED. ON THE FORECAST TRACK...ERNESTO WILL MOVE ACROSS THE EASTERN CARIBBEAN TODAY THROUGH SATURDAY...EVENTUALLY BRINGING OUTER BANDS OF MOISTURE TO THE LOCAL AREA...WITH CLOUDINESS...SHOWERS AND THUNDERSTORMS AND INCREASINGLY BREEZY TO WINDY CONDITIONS. DISCUSSION...AS THE PREVIOUS FORECASTER HAD ALLUDED TO... ALTHOUGH THE CENTER OF ERNESTO IS EXPECTED TO PASS A SAFE DISTANCE TO THE SOUTH OF THE LOCAL AREA...THE COMBINATION OF THE FORECASTED STRENGTHENING OF ERNESTO AND STRENGTHENING SURFACE HIGH PRESSURE NORTH NORTHEAST OF THE LOCAL AREA...WILL RESULT IN A TIGHTENING LOCAL PRESSURE GRADIENT...PRODUCING INCREASING FRESH TO LOCALLY STRONG WINDS ACROSS THE LOCAL ISLANDS...WITH BREEZY TO LOCALLY WINDY CONDITIONS EXPECTED. IN ADDITION...MOISTURE ON THE NORTH AND EAST SIDES OF THE SYSTEM...WILL BE PULLED UP ACROSS THE FA... RESULTING IN INCREASINGLY ACTIVE CONDITIONS LOCALLY BEGINNING LATE THIS AFTERNOON/EARLY THIS EVENING IN THE EAST AND THEN SPREADING WEST NORTHWEST. STILL LOOKS LIKE THE STRONGEST WINDS AND MOST SIGNIFICANT BANDS OF SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS ST CROIX...VIEQUES...THE SOUTH HALF OF PUERTO RICO AND THE ADJACENT COASTAL WATERS TONIGHT THROUGH SATURDAY...BUT WITH ALL AREAS RECEIVING INCLEMENT CONDITIONS. GIVEN WIND GUIDANCE VALUES (WHICH WE REMAIN AT LEAST 5 KNOTS BELOW IN THE GRIDS)...STILL APPEARS THAT A FEW AREAS COULD NEED A WIND ADVISORY LATE TONIGHT THROUGH SATURDAY AFTERNOON. IN TERMS OF RAINFALL...DESPITE THE RATHER QUICK AND MAINLY WESTWARD MOTION OF ERNESTO...MODELS CONTINUE TO INDICATE A GOOD SLUG OF DEEP TROPICAL MOISTURE BEING PULLED UP ACROSS THE FA AND LONG TERM SATELLITE LOOPS AND TPW PRODUCT...SHOW THE OVERALL MOISTURE ENVELOPE OF THE SYSTEM LIFTING/GROWING WEST NORTHWEST IN SUCH A MANNER...THAT A GENERAL 6 TO 12 HOUR PERIOD OF ACTIVE WEATHER SHOULD ENCOMPASS THE LOCAL ISLANDS. WE BELIEVE THAT EARLIER RAINFALL ESTIMATES OF A FEW INCHES OVER PARTS OF EAST AND SOUTH PUERTO RICO SHOULD VERIFY...WITH A COUPLE OF SPOTS POSSIBLY RECEIVING 5 INCHES AND GENERALLY LESSER AMOUNTS TO THE NORTH AND WEST. AVIATION...VFR CONDITIONS EXPECTED AT ALL LOCAL TAF SITES THROUGH THE FORECAST PERIOD. LLVL WINDS WILL REMAIN FROM THE NORTHEAST THRU TONIGHT...VEERING FROM THE EAST TO SOUTHEAST EARLY SATURDAY THRU SUNDAY. SUSTAIN WINDS OF 15 TO 25 KTS WITH HIGHER GUSTS UP TO 40 KTS ARE POSSIBLE DURING THE WEEKEND AS TS ERNESTO MOVES SOUTH OF THE FA. OUTER BANDS OF TS ERNESTO MAY AFFECT THE ISLANDS BTWN 04/06Z AND AT LEAST 05/12Z. MARINE...EXPECT INCREASING FRESH TO STRONG WINDS AND BUILDING HAZARDOUS SEAS ACROSS MOST OF THE LOCAL COASTAL WATERS...SPREADING WEST NORTHWEST FROM THE ANEGADA PASSAGE AND SOUTHEAST CARIBBEAN LATE THIS AFTERNOON/EARLY TONIGHT AND THEN EXPANDING ACROSS MOST AREAS. THE WORST CONDITIONS...WITH SUSTAINED WINDS OF 21 TO 27 KNOTS WITH GUSTS OF 35 TO 40 KNOTS AND SEAS BUILDING TO 7 TO 10 FEET SHOULD BE REALIZED ACROSS PARTS OF THE ANEGADA PASSAGE... LOCAL CARIBBEAN WATERS AND THE MONA PASSAGE...WITH SLIGHTLY LESS WIND AND LOWER SEAS TO THE NORTH. SMALL BOAT OPERATORS SHOULD EXERCISE CAUTION ACROSS THESE AREAS TODAY...WITH SMALL CRAFT ADVISORIES BEGINNING THIS EVENING/TONIGHT AND ALSO EXPANDING WEST NORTHWEST. FOR FORECAST MARINE CONDITIONS...PLEASE REFER TO OUR LOCAL MARINE PRODUCTS. && .PRELIMINARY POINT TEMPS/POPS... SJU 88 78 86 78 / 50 80 80 60 STT 81 80 84 80 / 50 50 50 30 && .SJU WATCHES/WARNINGS/ADVISORIES... PR... VI...NONE. COASTAL WATERS...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM AST SUNDAY FOR ANEGADA PASSAGE SOUTHWARD TO 17N. SMALL CRAFT ADVISORY FROM 11 AM TO NOON AST SATURDAY FOR COASTAL WATERS OF NORTHERN PUERTO RICO OUT 10 NM-COASTAL WATERS OF NORTHWESTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM AST SUNDAY FOR COASTAL WATERS OF SOUTHERN USVI VIEQUES AND EASTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO NOON AST SUNDAY FOR CARIBBEAN WATERS OF PUERTO RICO FROM 10 NM TO 17N. SMALL CRAFT ADVISORY FROM 2 AM SATURDAY TO NOON AST SUNDAY FOR COASTAL WATERS OF SOUTHERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM NOON SATURDAY TO NOON AST SUNDAY FOR COASTAL WATERS OF SOUTHWESTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON AST SUNDAY FOR ATLC WATERS OF PUERTO RICO AND USVI FROM 10NM TO 19.5N- MONA PASSAGE SOUTHWARD TO 17N. SMALL CRAFT ADVISORY FROM 6 AM SATURDAY TO 6 AM AST SUNDAY FOR COASTAL WATERS OF NORTHERN USVI AND CULEBRA OUT 10 NM. && $$ |
| #531499 (Received by flhurricane at: 12:05 PM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 1148 AM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL INTO EARLY NEXT WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A STATIONARY FRONT WILL STALL NORTH OF THE AREA MID TO LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LITTLE CHANGE HAS BEEN MADE TO THE FORECAST TODAY WITH THE EXCEPTION OF LOWERING TEMPS 1-2 DEGREES AND INCREASING POPS TO SLIGHT CHANCE FOR A SMALL CLUSTER OF SHOWERS/THUNDERSTORMS THAT CONTINUE TO DRIFT INLAND OVER COLLETON...DORCHESTER...AND BERKELEY COUNTIES. ONCE THESE SHOWERS/THUNDERSTORMS SHIFT FURTHER INLAND AND OUT OF THE FORECAST AREA...THE MAIN FOCUS OF CONVECTION WILL TURN TO A DEVELOPING SEABREEZE ALONG THE COAST EARLY THIS AFTERNOON. THE MODIFIED 12Z CHS SOUNDING INDICATES THERE WILL BE PLENTY OF INSTABILITY THIS AFTERNOON WITH SBCAPES RANGING FROM 2500-3000 J/KG AND LIFTED INDICES AS LOW AS -8C. SHEAR PROFILES WILL REMAIN WEAK THROUGH THIS EVENING. WITH THE LACK OF ANY SIGNIFICANT UPPER SUPPORT ALOFT...PULSE TYPE THUNDERSTORMS WILL BE THE PRIMARY FORM OF CONVECTION ALONG AND AHEAD OF AN INLAND MOVING SEABREEZE. ACTIVITY MAY EVOLVE INTO MORE OF A MULTICELL SCENARIO SHOULD CONVECTIVE OUTFLOWS BEGIN TO INTERACT. GIVEN THE AMOUNT OF INSTABILITY ALONG WITH DCAPES NEAR 1100 J/KG...WBZ HEIGHTS AROUND 12500 FT AND ANTICIPATED BOUNDARY INTERACTIONS...A FEW STORMS MAY BECOME STRONG WITH DAMAGING WINDS AND MARGINAL HAIL UNTIL SUNSET. THE BEST CHANCE OF STRONGER STORMS REMAINS BETWEEN 2 PM AND 8 PM THIS AFTERNOON/EVENING. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... ANY LINGERING CONVECTION WILL DISSIPATE BY LATE EVENING WITH THE LOSS OF INSOLATION AND CONVECTIVE OVERTURNING. CAN NOT COMPLETELY RULE OUT AN ISOLATED SHOWER/TSTM FIRING OVERNIGHT GIVEN THE NATURE OF THE AIRMASS IN PLACE...BUT PROBABILITIES FOR MEASURABLE RAINFALL WILL GENERALLY REMAIN LESS THAN 20 PERCENT. DEPENDING ON HOW QUICKLY DEBRIS CLOUDINESS WILL THIN...PATCHY FOG COULD DEVELOP WITHIN A LIGHT WIND REGIME. LOWS WILL RANGE FROM THE LOWER 70S INLAND TO THE UPPER 70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON. THE SOUTHEAST STATES WILL REMAIN BETWEEN TWO UPPER LEVEL RIDGES THROUGH THE WEEKEND...WITH THE WESTERN RIDGE LOCATED OVER THE CENTRAL PLAINS AND THE EASTERN RIDGE CENTERED OVER THE ATLANTIC WATERS. AT THE SURFACE...ATLANTIC HIGH PRESSURE WILL EXTEND OVER THE MID ATLANTIC AND SOUTHEAST STATES...AS A WEAK INLAND TROUGH TAKES SHAPE BY MONDAY. THIS TYPICAL SUMMERTIME PATTERN WILL SUPPORT A GENERAL SOUTH- SOUTHEAST ONSHORE FLOW AND ALLOW THE DAILY INLAND PROGRESSION OF THE SEABREEZE. EXPECT PULSE TYPE SHOWERS AND THUNDERSTORMS TO INITIATE EACH AFTERNOON AND EVENING...DRIVEN MAINLY BY SEABREEZE CONVERGENCE...MESOSCALE BOUNDARY INTERACTIONS AND DIURNAL HEATING/INSTABILITY. WEAK SHORTWAVE ENERGY ON SATURDAY WILL MOVE OUT OF THE AREA BY SUNDAY AND MONDAY AS THE ATLANTIC RIDGE BUILDS WESTWARD...LEAVING LITTLE UPPER LEVEL SUPPORT THROUGH THE SHORT TERM PERIOD. AS A RESULT...ANY ISOLATED TO SCATTERED CONVECTION WILL DIMINISH IN COVERAGE WITHIN WANING HEATING/INSTABILITY BY SUNSET. HAVE MAINTAIN SHOWER/THUNDERSTORM CHANCES IN THE 20 TO 30 PERCENT RANGE EACH DAY. ALTHOUGH AN ISOLATED STRONG STORM IS POSSIBLE WITH THIS PULSE TYPE CONVECTION AND BOUNDARY INTERACTIONS...THE OVERALL SEVERE WEATHER THREAT WILL REMAIN LOW OVER THE PERIOD. HIGH TEMPERATURES WILL REACH THE LOWER 90S EACH AFTERNOON AWAY FROM THE LOCALLY COOLER COASTLINE...WHILE LOW TEMPERATURES ONLY FALL INTO THE LOW TO MID 70S. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... UPPER LEVEL RIDGING WILL BEGIN TO WEAKEN EARLY NEXT WEEK...AS A TROUGH ALOFT AND SEVERAL SHORTWAVES MOVE ACROSS THE NEW ENGLAND STATES. AN ASSOCIATED COLD FRONT WILL LIKELY STALL WELL TO THE NORTH OF THE FORECAST AREA BY THE MIDDLE OF NEXT WEEK. AT THE SURFACE...THE INLAND TROUGH COULD BECOME MORE PROMINENT BETWEEN SURFACE HIGH PRESSURE OVER THE CENTRAL UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. CONSIDERING THE INCREASED FORCING FROM THE STALLED FRONT TO THE NORTH...COMBINED WITH INFLUENCES FROM THE LEE TROUGH AND BOUNDARY/SEABREEZE INTERACTIONS...CONVECTIVE POTENTIAL COULD BE GREATER THROUGH THE EXTENDED PERIOD. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS...WITH HIGH TEMPERATURES IN THE LOW TO MID 90S DURING THE AFTERNOON FALLING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... VFR WILL DOMINATE MUCH OF THE TAF PERIOD AT BOTH KCHS AND KSAV. SCATTERED TSTMS ARE EXPECTED THIS AFTERNOON...MAINLY WEST OF THE TERMINALS SO WILL LEAVE ANY MENTION OUT OF THE 03/12Z TAFS. THE NEED FOR TSRA WILL BE REEVALUATED WITH THE 03/18Z TAF CYCLE. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER THAN 30 PERCENT CONFIDENCE LEVEL AT THIS TIME. && .MARINE... THERE ARE NO MARINE CONCERNS THROUGH TONIGHT. A BROAD SOUTHERLY FLOW REGIME WILL DOMINATE WITH WINDS GENERALLY 10-15 KT AND SEAS 2-3 FT. ATLANTIC HIGH PRESSURE WILL EXPAND OVER THE WATERS THIS WEEKEND...SUPPORTING CONDITIONS BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO EARLY NEXT WEEK. IN GENERAL...SOUTH WINDS BETWEEN 10-15 KT WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE...WITH HIGHEST WINDS EXPECTED NEAR THE INLAND MOVING SEABREEZE CIRCULATIONS AND EARLY NOCTURNAL SURGES. WINDS COULD BRIEFLY BECOME SOUTHEAST EACH AFTERNOON/EVENING AS THE SEABREEZE PUSHES INLAND. SEAS WILL REMAIN BETWEEN 1-3 FT...WITH SWELLS FROM THE SOUTH/SOUTHEAST. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531498 (Received by flhurricane at: 11:56 AM 03.Aug.2012) AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 1033 AM CDT FRI AUG 3 2012 .UPDATE... LATEST SURFACE SHOWED 75 DEGREE DEWPOINT READINGS AS FAR NORTH AS THE MID SOUTH. HEAT INDEX VALUES WERE AROUND THE CENTURY MARK AT BTR...ASD...MSY...NEW AND HUM. ISOLATED TO SCATTERED CONVECTION IS EXPECTED ACROSS THE EAST HALF OF THE FORECAST AREA BUT THIS MAY NOT PROVIDE ENOUGH RELIEF THROUGH THIS AFTERNOON. SOUTHWEST MISSISSIPPI INCLUDING MCB MANAGED TO DROP BELOW 75 FOR SOME TIME THIS MORNING AND PROVIDE SOME RELIEF FROM THE HEAT. ALL IN ALL...HEAT ADVISORY WILL BE ISSUED FOR FORECAST AREA EXCEPT SOUTHWEST MISSISSIPPI AND MCCOMB AREA FOR NOW. && .PREV DISCUSSION... /ISSUED 821 AM CDT FRI AUG 3 2012/ UPDATE... ..SOUNDING DISCUSSION... NO PROBLEMS WITH THE FLIGHT THIS MORNING. PW VALUES ARE UP SLIGHTLY TO 2.15 INCHES WITH A LARGE AMOUNT OF CAPE IN THE COLUMN. A POCKET OF DRIER AIR REMAINS IN THE MID LEVELS THIS MORNING WITH THE SURFACE WINDS REMAINING LIGHT WITH HIGH PRESSURE REMAINING IN CONTROL. ANY THUNDERSTORMS THAT DEVELOP WILL HAVE THE POSSIBILITY OF BECOMING STRONG WITH WIND GUSTS OF 35 TO 40 MPH AND SMALL HAIL POSSIBLE. 98/SO PREV DISCUSSION... /ISSUED 405 AM CDT FRI AUG 3 2012/ SHORT TERM... UPPER LEVEL RIDGE TO THE WEST OF THE AREA CONTINUES TO BE THE CONTROLLING FACTOR FOR LOCAL CONDITIONS. TEMPERATURES AND DEWPOINTS ARE IN GENERAL ABOUT A DEGREE OR SO COOLER AREAWIDE. LOOKING UPSTREAM...NOT MUCH IN THE WAY OF THICK CLOUD COVER AS WHAT OCCURRED YSTRDY. SO NOT THINKING THAT HIGHS WILL BE LIMITED AS MUCH AND SHOULD REACH CLOSER TO FCST. HAVE BUMPED UP TD/S FROM GUIDANCE DUE TO ITS LOW BIAS ALL WEEK LONG. COMBINATION OF T/TD WILL ONCE AGAIN BRING HEAT INDICIES RIGHT TO 100 TO 105 RANGE. HAVE QUITE WIDE RANGE IN GUIDANCE ON POPS TODAY. MAV IS ON THE DRIER SIDE WITH GENERALLY 20 PERCENT ACROSS THE AREA. MET/NAM IS MUCH HIGHER AT 50 TO 60 PERCENT AND ECMWF IS AROUND 40. MET/NAM JUST SEEMS TO BE WAY TO AGGRESSIVE...ESPECIALLY WHEN CONSIDERING HOW LITTLE CONVECTION HAS ACTUALLY DEVELOPED OVER THE LAST FEW DAYS. REALLY DONT SEE MUCH IN THE WAY OF A SIGNIFICANT SHORTWAVE NORTH OF THE AREA TO PRODUCE WIDESPREAD DEVELOPMENT. WHAT WILL MORE THAN LIKELY OCCUR IS JUST A FEW STORMS DEVELOPING ALONG SEA BREEZE AND OTHER BOUNDARIES LEFT OVER FROM YSTRDY. SO HAVE GONE WITH THE DRIER MAV FOR POPS TODAY. PROBABLY WILL BE JUST AS UNSTABLE AS YESTERDAY AND A FEW STRONG STORMS WITH SMALL HAIL ARE POSSIBLE. LONG TERM... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH DIGGING INTO THE PACIFIC NORTHWEST THIS MORNING. THIS SYSTEM IS EXPECTED TO SWIFTLY TRACK ACROSS THE NORTHERN HALF OF THE COUNTRY...REACHING THE UPPER MISSISSIPPI VALLEY BY LATE SATURDAY. THIS WILL SUBSTANTIALLY COMPRESS THE RIDGE OVER OUR AREA. SO ITS NO SURPRISE THAT CONVECTION WILL BE ON THE INCREASE THIS WEEKEND WITH LESS SUBSIDENCE. FOR NOW MAINTAINED PREVIOUS FCST POPS ON SATURDAY AT 30 TO 40 PCT BUT DID INCREASE SUNDAY TO 50 PCT COVERAGE WHICH MAY BE A LITTLE CONSERVATIVE. EARLIER NEXT WEEK...A WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE PROGRESSIVE UPPER TROUGH WILL SAG TOWARDS THE CWA. IT WILL BE THE FOCUS FOR CONTINUED INCREASED DAILY CONVECTION. REGARDING TROPICAL STORM ERNESTO...THE STORM IS STILL UNDER THE INFLUENCE OF QUITE A BIT OF SHEAR AND IT STRUGGLING TO MAINTAIN CONVECTION AROUND THE CENTER OF CIRCULATION. THE SHEAR IS EXPECTED TO BE MUCH LESS IN ABOUT 2 DAYS. FROM THAT POINT THE STORM WILL BE IN MORE FAVORABLE CONDITIONS FOR STRENGTHENING OR EVEN JUST REDEVELOPMENT IF IT CONTINUES TO WEAKEN OVER THE NEXT COUPLE DAYS. THE STRENGTH OF THIS STORM WILL BE A MORE IMPORTANT FACTOR IN ITS LONG TERM TRACK. WEAKER SYSTEM WOULD TEND TO STAY FURTHER SOUTH ON A MORE WESTERLY TRACK. STRONGER SYSTEM WOULD LIKELY FEEL THE WEAKNESS IN THE RIDGE TO THE NORTH AND WANT TO STEER ON A MORE WNW TRACK. WHATEVER IT MAY BE...THE SYSTEM SHOULD BE NEAR THE WESTERN CARRIBEAN BY EARLY TO MID NEXT WEEK. MEFFER AVIATION... MAINLY VFR CONDITIONS WILL CONTINUE TO PREVAIL AT THE TAF SITES THROUGH 12Z SATURDAY. ISOLATED TO SCATTERED CONVECTION MAY IMPACT THE TERMINALS IN THE EASTERN HALF OF THE FORECAST AREA THIS AFTERNOON. 11 $$ |
| #531497 (Received by flhurricane at: 11:56 AM 03.Aug.2012) AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 1110 AM EDT Fri Aug 3 2012 .NEAR TERM...[Today] For today we are expecting scattered showers across the area, with a 40 percent chance in the northeastern portion, and a 50 percent chance across the rest of the area. This was mainly based off of the sea breeze circulation, classifying today as a regime 6. Upper air data from 12 UTC does show an upper low developing off the Northeast Florida Coast, but this feature is a little far away today to create an impact on our local weather. The 12 UTC KTAE sounding shows the potential for moderate instability this afternoon (though not as high as what we saw on Thursday). The sounding also shows that storm motion at 0-6 km is essentially at 0 knots. This means that the convection that does develop today will most likely move very little. As a result, the strongest storms could produce areas of localized flooding. With a little more cloud cover today, temperatures will be in the low 90s all across our region. && .SHORT TERM... [Tonight through Sunday] Scattered diurnal convection will diminish tonight. On Saturday and Sunday, differences start to emerge between the NAM and the GFS. The NAM moves a weak tropical wave through the area on Saturday, and the GFS holds off until Sunday. Both models have an upper level shortwave dropping south and affecting the western zones on Saturday, so the likely PoPs from the previous forecast were maintained across that area. Elsewhere, scattered convection is expected on Saturday. PoPs were increased to likely on Sunday across northwest Florida in favor of the GFS with the expectation that a weak tropical wave will move westward through the area with increased moisture late in the day. This has some support from the 00z ECMWF as well. Seasonably warm temperatures are expected. && .LONG TERM... [Sunday night through next Friday] Weak tropical wave axis is forecast to pass across the forecast area late Sunday into Monday. With the southeasterly flow in the wake of the wave and a weakness aloft between subtropical ridges to the east and west, expect deep layer moisture to remain elevated on Monday with at least scattered showers and thunderstorms across the entire forecast area. The onshore low-level flow trajectory is expected to continue through at least Thursday, keeping PoPs elevated and temperatures near seasonal norms. && .AVIATION... [through 12Z Saturday] Fog has once again developed this morning across parts of Southwest and South Central GA. This fog has produced VLIFR conditions at ABY. IFR ceilings are being reported DHN with MVFR at ECP. The 12Z KTAE sounding shows that the surface inversion is very shallow this morning. Therefore, we expect the lowest conditions to improve rapidly, by around 13Z or possibly as late as 14Z. After VFR conditions establish themselves later this morning, a typical summertime pattern is expected for the rest of today, with scattered thunderstorms this afternoon and evening. Best chances for TSRA this afternoon appear to be at the FL terminals, where tempos are included in the forecast. && .MARINE... A ridge of high pressure south of the area is expected to keep light onshore winds through today. A tropical wave will then move west across the area late in the weekend swinging winds around to the east and southeast. A trough will establish itself north of the waters early next week with a ridge to the south. This will bring a return to light onshore winds. && .FIRE WEATHER... Afternoon Relative Humidity levels are expected to remain above critical thresholds for the next week, so red flag conditions are not expected. && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ |
| #531496 (Received by flhurricane at: 11:08 AM 03.Aug.2012) AFDTBW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL 1055 AM EDT FRI AUG 3 2012 .UPDATE (REST OF TODAY)... 14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE FLORIDA PENINSULA CONTINUES TO RESIDE UNDERNEATH A SUBTLE WEAKNESS IN THE HEIGHT FIELDS TO THE EAST OF AN IMPRESSIVE AND DOMINANT UPPER LEVEL RIDGE ACROSS THE SOUTHERN PLAINS. THIS UPPER RIDGE IS ACTUALLY ONE OF THE MORE VISUALLY IMPRESSIVE ANTICYCLONES ON WV IMAGERY THAT THIS FORECASTER HAS SEEN...WITH A VERY SYMMETRIC LOOK OF DRY AIR/SUPPRESSION AT ITS CORE AND RINGED BY A MID/UPPER LEVEL MOISTURE BELT. LOOKING AT THE LARGER PICTURE...THE MAIN NORTHERN STREAM FLOW IS HELD BY THIS RIDGE UP ALONG THE U.S/CANADIAN BORDER. AN IMPRESSIVE DISTURBANCE WITHIN THIS FLOW IS CURRENTLY DROPPING OUT OF THE CANADIAN ROCKIES INTO THE HIGH PLAINS. THIS ENERGY WILL LIKELY BE THE FOCUS FOR A ROUND OF STRONG/SEVERE STORMS ACROSS THE HIGH PLAINS STATES LATER TODAY. AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS HAS SHIFTED NORTHWARD OVER THE PAST 24 HOURS AND IS NOW ALIGNED OVER THE NORTHERN FL PENINSULA/NE GULF OF MEXICO. ROTATING AROUND THE SOUTHERN PERIPHERY OF THIS RIDGE WE FIND A RATHER WELL DEFINED INVERTED TROUGH/TROPICAL WAVE FEATURES CROSSING THE BAHAMAS AND APPROACHING THE FL EAST COAST. THIS FEATURE IS THE FOCUS FOR QUITE A BIT OF CONVECTION TO THE EAST OF FLORIDA...BUT SO FAR HAS NOT MOVES FAR ENOUGH WEST TO SIGNIFICANTLY INFLUENCE THE CONVECTIVE POTENTIAL FOR OUR REGION. MOSTLY SUNNY SKIES HAVE BEEN RULE ACROSS THE FL WEST COAST THIS MORNING. THIS NEAR MAX OF INSOLATION HAS ALLOWED TEMPS TO QUICKLY WARM INTO THE MID/UPPER 80S...AND WE ARE JUST ABOUT AT THE POINT TO INITIATE THE SEA-BREEZE. WILL SEE A SCT CU FIELD BEGIN DEVELOPING WITH THIS SEA-BREEZE WITHIN THE NEXT HOUR OR 2...ALONG WITH A FEW ISOLATED SHOWERS. THE CURRENT THINKING ON THE MOST LIKELY CONVECTIVE CYCLE FOR THE REMAINDER OF THE DAY WILL BE FOR ISOLATED-WDLY SCT SHOWERS/STORMS EARLY THIS AFTERNOON WHICH WILL MIGRATE INLAND FROM THE I-75 CORRIDOR. THEREAFTER...WITH THE APPROACH OF THE SURFACE WAVE FROM THE EAST...WILL SEE OUR 1000-700MB FLOW TRANSITION TO A MORE EASTERLY DIRECTION. THIS SYNOPTIC INFLUENCE SHOULD HELP PROPEL THE EAST COAST SEA-BREEZE ACROSS THE PENINSULA BY LATE AFTERNOON/EARLY EVENING. THE INTERACTION OF BOTH SEA-BREEZES SHOULD BE GREATEST FROM TAMPA BAY SOUTHWARD WHERE A SECOND ROUND OF CONVECTION MAY ACTUALLY PUSH BACK TOWARD THE WEST COAST WITH TIME. MID-LEVEL CONVECTIVE POTENTIAL IS ACTUALLY VERY FAVORABLE FOR DEEP CONVECTION WITH THETAE VALUES IN THE LOWER 330S. OUR LOCAL HIRES GUIDANCE ALONG WITH SEVERAL OF THE NATIONAL HI-RES MEMBERS ARE SHOWING SOMETHING SIMILAR TO THIS SCENARIO. && .PREVIOUS DISCUSSION (TONIGHT THROUGH SUNDAY)... THE TROUGHINESS ALOFT CONTINUES TO WEAKEN AS IT SLIDES WEST OVER THE GULF AS THE UPPER RIDGE IN THE ATLANTIC BEGIN TO BUILD SOUTHWESTWARD TODAY. THE SURFACE RIDGE AXIS LIFTS UP INTO NORTHERN FL AS THE TROPICAL WAVE APPROACHES THE EAST FL COAST. ON SAT - THE UPPER RIDGE SPREADS OVER FL AS THE SURFACE RIDGE AXIS MOVES INTO SOUTHERN GA WITH THE TROPICAL WAVES CROSSING THE STATE TO THE WEST COAST. FOR SUN - BOTH THE UPPER AND SURFACE RIDGES PIVOT NORTH... TO THE SE U,S. COAST AS THE WAVE SLIDES OUT OVER THE GULF. THE SW AND WEST LOW LEVEL FLOW OF THE PAST FEW DAYS WILL GIVE WAY TO SOUTHEAST AND THEN EASTERLY FLOW AS THE RIDGE AXIS MOVES NORTH AND THE WAVE CROSSES THE AREA. THE PREVAILING LOW LEVEL FLOW THEN BACKS TO SE SUN AS THE RIDGE CONTINUES NORTH AND THE WAVE MOVES AWAY. THE FLOW WILL BE LIGHT ENOUGH FOR SEA BREEZE CIRCULATIONS EACH DAY...HOWEVER THE MORE EASTERLY FLOW SAT WILL KEEP THE SEA BREEZE CLOSE TO THE COAST. THE ATMOSPHERE MOISTENS WITH PWAT VALES RUNNING OVER 2 INCHES THROUGH THE WEEKEND. THE FORECAST WILL BE TYPICAL FOR EARLY AUGUST. THE MOIST AIR MASS...SEA BREEZE CONVERGENCE...AND DAY TIME HEATING WILL RESULT IN ISOLATED BECOMING SCATTERED CONVECTION DURING THE DAY THAT LINGERS INTO THE EVENING. EXCEPT SUN WILL SEE NUMEROUS STORMS OVER COASTAL LOCATIONS DUE TO A MORE ROBUST SEA BREEZE. THIS PATTERN FAVORS A FEW STORMS BECOMING STRONG WITH THE GREATEST THREAT WIND. TEMPERATURES WILL RUN JUST ABOVE NORMAL ALTHOUGH THE HIGHS WILL DIP A DEGREE OR TWO BETWEEN THIS AFTERNOON AND SUN. && .AVIATION... MAINLY VFR TODAY WITH JUST ISOLATED TO WIDELY SCATTERED STORMS AROUND AFTER 15Z. CONFIDENCE IN COVERAGE AND TIMING TOO LOW TO INCLUDE TEMPO GROUPS AT THIS TIME. && .MARINE... SOUTH AND SW WINDS WITH AN AFTERNOON SEA BREEZE FOR TODAY WILL SHIFT TO SE AND EAST FOR THE WEEKEND AND EARLY NEXT WEEK...BUT WITH A SEA BREEZE NEAR THE COAST IN THE AFTERNOONS. WITH WIND SPEEDS OF 10 KT OR LESS THE MAIN MARINE HAZARD WILL BE ISOLATED TO SCATTERED THUNDERSTORMS. && .PRELIMINARY POINT TEMPS/POPS... TPA 92 77 92 76 / 40 20 40 30 FMY 93 75 92 75 / 40 20 50 30 GIF 94 74 93 74 / 40 30 50 20 SRQ 92 75 92 75 / 40 20 40 30 BKV 93 71 92 72 / 30 20 40 30 SPG 91 79 91 76 / 30 20 40 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ |
| #531495 (Received by flhurricane at: 10:57 AM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1048 AM EDT FRI AUG 3 2012 .SYNOPSIS... VERY WARM AND HUMID WEATHER WILL PERSIST THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND THUNDERSTORMS...BUT SHOWERS AND THUNDERSTORMS ARE MORE LIKELY MONDAY WHEN A COLD FRONT CROSSES SOUTHERN NEW ENGLAND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST BY THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... 1030 AM UPDATE... NOT MUCH CHANGE FROM PREVIOUS FORECAST SO LITTLE CHANGE EXPECTED. STRATUS AND FOG CONTINUE TO DISSIPATE ALONG THE SOUTH COAST AND SHOULD COMPLETELY ERODE BY MIDDAY. VERY WARM AND MUGGY DAY IN PROGRESS AND UPSTREAM 12Z ALY SOUNDING SUPPORTS CURRENT HIGH TEMPS OF U80S TO L90S. NEW 12Z NAM ONLY SUPPORTS ISOLATED TO WIDELY SCATTERED STORMS THIS AFTERNOON AND THIS SEEMS REASONABLE GIVEN WEAK DEEP LAYER SHEAR AND WEAK FORCING FOR ASCENT...DESPITE MODEST INSTABILITY. THIS SHOULD KEEP STORMS DISORGANIZED AND SHORT LIVED/PULSE TYPE. 12Z HRRR CONFINES MOST OF THE ACTIVITY TO NORTHERN MA AND SOUTHWEST NH AND DOESN/T DEVELOP MUCH UNTIL 20Z. THIS WILL PROVIDE A SHORT WINDOWN OF OPPORTUNITY AS CONVECTION SHOULD DISSIPATE TOWARD SUNSET. THUS MOST STORMS SHOULD REMAIN SUB- SEVERE WITH MAIN THREAT BEING HEAVY RAIN. ALTHOUGH GIVEN PULSE MODE STORMS SHOULD BE SHORT IN DURATION LIMITING FLOOD THREAT. PREVIOUS DISCUSSION... MAIN CONCERN TODAY DEALS WITH POTENTIAL FOR SHOWERS AND THUNDERSTORMS. 00Z MODELS SHOW PLENTY OF INSTABILITY WITH SURFACE BASED CAPES 1500-2500 J/KG AND MARGINAL MID LEVEL LAPSE RATES NEAR 6C/KM. HOWEVER WINDS ALOFT REMAIN RATHER WEAK WHICH LEADS TO POOR 0-6KM SHEAR. APPROACHING COLD FRONT IS EXPECTED TO WEAKEN AS IT REACHES SOUTHERN NEW ENGLAND THIS AFTERNOON...BUT SHOULD BECOME FOCUS FOR SCATTERED SHOWERS/STORMS TO DEVELOP. MAIN THREAT WILL BE LOCALLY HEAVY RAIN...BUT PER SPC DAY 1 OUTLOOK THERE IS ALSO A LOW PROBABILITY OF STRONG WIND GUSTS AND HAIL IF HIGHER CORES CAN MANAGE TO DEVELOP. PROBABLY LOOKING AT PULSE STORMS WHICH MAY ATTEMPT TO FORM INTO BOWING SEGMENTS. EXPECT INITIAL ACTIVITY TO REACH SW NH AND NW MA LATER THIS MORNING /HRRR LOOKS REASONABLE WITH 14Z-15Z ONSET/...BUT EXPECT MOST OF STORMS WILL OCCUR BETWEEN NOON AND 5 PM ALONG MASS PIKE CORRIDOR AND INTO HARTFORD AND PROVIDENCE. NOT CONFIDENT STORMS WILL FIRE CLOSER TO S COAST GIVEN STABILIZING SW FLOW...BUT WITH FAIRLY HIGH CAPE STORMS CANNOT BE RULED OUT DOWN THERE EITHER. 850 MB TEMPERATURES ARE PROGGED TO REACH 17-18C WHICH WOULD YIELD HIGHS IN 90S WITH FULL SUN. NAM MOS HAS LOW TO MID 90S ACROSS MUCH OF AREA WHICH LOOKS A LITTLE HIGH GIVEN SOME EXPECTED CLOUD COVER... SO LEANED MORE TOWARD GFS MOS TODAY WITH MID 80S TO MID 90S. DEWPOINTS NEAR 70 /ESPECIALLY S OF MASS PIKE/ YIELDS HEAT INDICES IN MID TO UPPER 90S WHICH IS BELOW HEAT ADVISORY CRITERIA. && .SHORT TERM /SATURDAY/... ISOLATED SHOWERS/STORMS WILL BE SLOW TO DIMINISH THIS EVENING DESPITE LOSS OF DAYTIME HEATING DUE TO PLENTY OF LOW LEVEL MOISTURE AND WEAK CONVERGENCE ALONG DISSIPATING FRONT. SHOULD SEE ANOTHER NIGHT OF LOW CLOUDS AND PATCHY FOG...MAINLY NEAR S COAST. USED A BLEND OF GFS/NAM MOS WHICH ARE CLOSE TO EACH OTHER. COLD FRONT WILL HAVE WASHED OUT OVER SOUTHERN NEW ENGLAND SAT...BUT SHOULD STILL BECOME A FOCUS FOR SCATTERED SHOWERS AND STORMS ONCE AGAIN. MODELS INDICATE THIS MAY BEGIN A BIT EARLIER THAN TODAY...BY MID TO LATE MORNING...AS SOME WEAKENING UPSTREAM CONVECTION COMES INTO PLAY. LOOKS LIKE ANOTHER DAY WITH POTENTIALLY HIGH CAPE AND WEAK SHEAR BUT WITH BETTER MID LEVEL LAPSE RATES...SO POTENTIAL FOR GUSTY WINDS AND HAIL MAY BE A LITTLE HIGHER THAN TODAY. LEANED CLOSER TO GFS MOS FOR HIGHS GIVEN EXPECTED CLOUD COVER AND A POSSIBLE EARLIER START TO CONVECTION...IN 80S TO AROUND 90. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... * QUIET AND MILD SAT NGT * RAIN BECOMING WIDESPREAD SUN-MON ALONG AND AHEAD OF A COLD FRNT * HEAVY RAIN EXPECTED...FLOODING IS A DISTINCT POSSIBILITY * ENERGY OFFSHORE AROUND TUE MORN...QUIET WX EXPECTED INTO WED * ANOTHER DISTURBANCE PSBL INTO THE END OF THE WEEK MODEL DIAGNOSIS... MDL SOLNS ARE STILL TRENDING WITH A PERSISTENT GENERAL PATTERN OF A DEEP POLAR VORTEX ACROSS THE NRN HUDSON BAY RGN WITH A SERIES OF DISTURBANCES ROTATING AROUND THE PERIMETER AND ACROSS THE NERN CONUS. MEANWHILE STRONG RIDGING PERSISTS THRU THE ATLANTIC AND WRN ROCKIES. THE MID-HIGH LATITUDE BLOCKING PATTERN KEEPS AN ACTIVE PATTERN FOR THE FCST. BUT WATCHING A PSBL EWD SHIFT IN THE PATTERN OVER THE NWRN CONUS BY THE FOLLOWING WEEK AS A SERIES OF DISTURBANCES PROMOTE DEEP TROUGHING THRU THE GULF OF ALASKA...CONSEQUENTIALLY SHIFTING THE MAIN RIDGE OF HIGH PRES ACROSS THE CENTRAL CONUS TOWARDS THE ERN CONUS. OVERALL...WHILE MDL SOLN CONTINUITY HAS PERSISTED INTO THE BEGINNING OF NEXT WEEK WITH THE 02/12Z GUIDANCE...THEREAFTER IT HAS REMAINED UNCERTAIN DUE TO RUN TO RUN VARIABILITY OF TIMING/PHASING OF KEY FEATURES ACROSS THE MID-HIGH LATITUDES. HPC HAS EMPHASIZED A MORE CONSENSUS APPROACH WITH EQUAL WEIGHTING OF DETERMINISTIC AND ENSEMBLE MDL SOLNS. OF GREATER CERTAINTY...MDL SOLNS IN BETTER AGREEMENT OF ACTIVITY INITIATING SUNDAY AND CONTINUING SUNDAY NIGHT INTO MONDAY WITH THE APPROACH OF A SFC COLD FRNT. AM STILL CONCERNED OVER THE PROLONGED PERIOD OF SUB-TROPICAL MOISTURE FETCH NEWD ACROSS NEW ENGLAND AHEAD OF THE COLD FRNT /PWATS AROUND 2.25 IN/ WARRANTING THE POSSIBILITY OF FLOOD WATCHES. BETTER AGREEMENT OF THE COLD FRNT AND ATTENDANT ENERGY OFFSHORE BY TUE MORN. AND FINALLY...THERE IS ALSO SLIGHTLY BETTER CONSENSUS OF A FOLLOW UP DISTURBANCE BY THE END OF THE WEEK. SATURDAY NIGHT... CONVECTIVE ELEMENTS DURING THE DAY DIMINISH AS WEAK HIGH PRES TAKES CONTROL. SLY FLOW ENHANCING THRU THE EVNG IN RESPONSE TO THE APPROACHING SYNOPTIC SYS ACROSS THE GRT LKS BY SUNDAY MORN. WILL SEE A SURGE OF LOW 70 DEWPOINTS TOWARDS THE S SHORE OF NEW ENGLAND. CANT RULE OUT THE DEVELOPMENT OF LOW STRATUS AND FOG FOR SHORELINE COMMUNITIES. SHOULD BE A MILD NIGHT WITH MINS RANGING FROM THE UPR 60S TO LOW 70S /MID 70S PSBL/. SUNDAY THROUGH MONDAY... THE COMBINATION OF ENHANCED LOW-MID LVL FLOW OF SUB-TROPICAL AIR FROM THE SERN CONUS ON SUNDAY CONVERGENT ALONG A PSBL PRE-FRONTAL TROUGH...AND DESTABILIZATION OF THE LOCAL BOUNDARY LYR...WARRANTS CHC POPS FOR SUNDAY INTO SUNDAY NGT. ADVERTISED PWATS DURING THIS TIMEFRAME ARE AROUND 2 INCHES WITH MDL SOUNDINGS INDICATED A FAIRLY MOIST ADIABATIC PROFILE WITH THIN ELONGATED CAPE THRU THE ATMOS COLUMN OF 500-1000 J/KG. PRESENT THINKING IS FOR SHOWERS AND THUNDERSTORMS TO INCREASE IN AERIAL COVERAGE THRU THE DAY ACROSS THE MID-ATLANTIC NEWD INTO NEW ENGLAND. BEST POP CHCS WILL BE OVER WRN AND CENTRAL NEW ENGLAND. WHILE STORMS /LIKELY PULSY IN NATURE/ ARE EXPECTED TO BE SUB-SEVERE...HEAVY RAIN WILL BE A THREAT. ACTIVITY SHOULD CONTINUE SUNDAY NIGHT INTO MONDAY ALONG AND AHEAD OF THE COLD FRNT FCST TO SLIDE THRU THE RGN AND OFFSHORE BY TUE MORN. FRONTOGENETICAL FORCING OF CONTINUED LOW-MID LVL SWLY ADVECTION OF SUB-TROPICAL AIR SHOULD LEND TO LIKELY POPS FOR SHOWERS AND THUNDERSTORMS. SOME UNCERTAINTY AS TO WHETHER CLOUDS WILL BREAK ALLOWING FOR DESTABILIZATION OF THE BOUNDARY LYR ON MONDAY. NEVERTHELESS THE POSSIBILITY FOR ELEVATED CONVECTION EXISTS WITH CAPE VALUES HOVERING AROUND 500-1000 J/KG WITHIN A VERY MOIST ADIABATIC ENVIRONMENT. EXPECTED EMBEDDED HEAVIER RAINS WITH PULSE TYPE CONVECTION. PWATS ADVERTISED AROUND 2.25 INCHES AHEAD OF THE COLD FRNT WARRANT THE POSSIBILITY OF FLOODING. TUESDAY AND TUESDAY NIGHT... LOOKS TO REMAIN DRY WITH WEAK HIGH PRES ACROSS THE RGN IN WAKE OF MONDAYS DISTURBANCE SITTING OFFSHORE OF NEW ENGLAND. SLIGHTLY COOLER AND DRIER AIR BUILDS INTO THE RGN /H85 TEMPS AROUND +14C/. LGT AND VRB W/SWLY FLOW. WEDNESDAY THROUGH FRIDAY... A SECOND DISTURBANCE WITH ATTENDANT COLD FRNT IS EXPECTED TO SLIDE THRU THE RGN...USURPING ONCE AGAIN BETTER SUB-TROPICAL MOISTURE FROM THE SERN CONUS. MDL SOLNS VARY WITH OUTCOMES BASED ON EVOLUTION OF MID-LYR FEATURES THRU THE MID-HIGH LATITUDES. AM SOMEWHAT HESITANT TO ACCEPT THE 03/0Z GFS SOLN...RATHER AM MORE FAVORABLE TO THE SIMILAR TRENDS PER 03/0Z CANADIAN AND 02/12Z ECMWF. WILL HINT AT PRECIP FOR WED-THURS...WITH IMPROVEMENT FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND WITH ACTIVITY SHUNTED OFFSHORE BY HIGH PRES BUILDING S OUT OF CANADA. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW...MODERATE CONFIDENCE. 1030 AM UPDATE... IFR CIGS ALONG THE SOUTH COAST CONTINUE TO ERODE AND SHOULD COMPLETELY DISSIPATE BY MIDDAY. OTHERWISE FOCUS WILL BE FOR A FEW AFTN ISOLATED TSRA 18-20Z THRU CENTRAL NEW ENGLAND...SLIDING SEWD TOWARDS SERN NEW ENGLAND TOWARDS 22-0Z. ANY IMPACTS TO TERMINALS MAY RESULT IN +SHRA/+TSRA WITH MVFR-IFR VSBYS. STORMS SHOULD DISSIPATE WITH SUNDOWN. WITH SLY FLOW CONTINUING... PERSISTENCE SHOULD DOMINATE AS WE HAVE SEEN THE PAST COUPLE OF EVNGS OF LOW STRATUS AND FOG DEVELOPING ACROSS THE S/SE COASTLINE OF NEW ENGLAND...BUILDING INTO THE INTERIOR. EXPECT LOCALES ACROSS THE S COAST TO FALTER TO VSBYS AROUND 1SM AND CIGS BELOW 500 FT AGL. INTO SATURDAY...LOW CIGS AND FOG DISSIPATE DURING THE MORNING HRS FOLLOWED BY MIDDAY-AFTN CONVECTION. KBOS TAF...MODERATE CONFIDENCE. NO CHANGES FROM PREVIOUS FORECAST...PREVAILING VFR WITH SCTD AFTN CONVECTION PSBL. AM NOT CONFIDENT OF ANY VSBY AND/OR LOW CIG IMPACTS FOR TONIGHT INTO SAT. KBDL TAF...MODERATE CONFIDENCE. NO CHANGES FROM PREVIOUS FORECAST...CONVECTION PSBL INTO THE AFTN HRS...DISSIPATING BY SUNDOWN. EXPECTING SOME MVFR VSBY IMPACTS CLOSER TO THE MORNING HRS SATURDAY. OUTLOOK...SUNDAY THROUGH TUESDAY... SATURDAY NIGHT...MODERATE TO HIGH CONFIDENCE. EXPECTING FOG AND LOW STRATUS /IFR-LIFR IMPACTS/ ALONG THE S COAST ADVECTED NWD BY INCREASING SLY FLOW. THRU THE INTERIOR...MID-UPR LVL CLOUDS ON THE INCREASE...PREVAILING VFR. SUNDAY THROUGH MONDAY...MODERATE CONFIDENCE. INCREASING AERIAL EXTENT OF SHRA/TSRA ALONG AND AHEAD OF AN APPROACHING COLD FRNT FROM THE W. SHRA/TSRA MAY BE HEAVY AT TIMES... ESPECIALLY MONDAY AS THE COLD FRNT TRAVERSES THE TERMINALS... PUSHING OFFSHORE BY TUE MORN. PREVAILING MVFR-VFR...TEMPO IFR VSBY IMPACTS WITH +SHRA/+TSRA. ESPECIALLY DURING EVNG PDS...EXPECTING FOG AND LOW STRATUS ALONG THE S COAST WITH IFR-LIFR IMPACTS. STRONG SLY FLOW WITH GUSTS UP TO 25 KTS THRU THE ENTIRE PD. TUESDAY...MODERATE CONFIDENCE. WLY WIND FLOW. PREVAIL VFR. LESSER CHCS FOR FOG AND LOW STRATUS. && .MARINE... FOG CONTINUES TO DISSIPATE ALONG THE SOUTH COAST AND SHOULD COMPLETELY ERODE BY MIDDAY. FAIRLY CONFIDENT WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH SAT. SW WINDS GUST TO 20KT ALONG S COAST THIS AFTERNOON...WHICH INCLUDES BUZZARDS BAY AND VINEYARD SOUND...BUT PROBABILITY OF REACHING 25KT IS LOW. SEAS WILL CONTINUE TO BUILD SLOWLY ON S COASTAL WATERS DUE TO PERSISTENT SW FLOW BUT ARE NOT EXPECTED TO REACH 5 FT. MAIN HAZARDS INCLUDE SCATTERED TSTMS THIS AFTERNOON AND SAT AFTERNOON...MAINLY FROM NARRAGANSETT BAY TO BOSTON HARBOR AND MERRIMACK RIVER...AND PATCHY DENSE FOG ON S COASTAL WATERS LATE TONIGHT AND SAT MORNING. OUTLOOK...SUNDAY THROUGH TUESDAY... INCREASING SLY FLOW ALONG AND AHEAD OF AN APPROACHING COLD FRNT WILL RESULT IN SWELL AND HIGH SEAS ACROSS THE S WATERS /WAVE HEIGHTS OF AROUND 7 FT FOR THE OUTER WATERS...WITH 5-7 FT FOR THE INNER WATERS ALONG THE S COAST/. E WATERS WILL GRADUALLY RISE AS WELL. GUSTS UP TO 25 KTS CAN BE EXPECTED BEGINNING LATE SUNDAY THROUGH TUE BY WHICH POINT THE COLD FRNT WILL HAVE SHUNTED E...TRANSITIONING OUT TO SEA. AERIAL EXTENT OF SHOWERS AND THUNDERSTORMS WILL INCREASE THRU THE PD...BEGINNING SUNDAY. SOME OF THESE STORMS...ESPECIALLY ALONG AND AHEAD OF THE COLD FRNT...WILL BE ASSOC WITH HEAVY RAIN AND REDUCED VSBYS. RAINS AND ACTIVITY SHOULD BE E OF THE WATERS BY LATE MORN INTO MIDDAY TUE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ004>006- 009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...SIPPRELL/JWD |
| #531490 (Received by flhurricane at: 10:47 AM 03.Aug.2012) AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1043 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE COAST TODAY....AND WILL REMAIN OFF THE COAST THIS WEEKEND. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION EARLY MONDAY. && .NEAR TERM /THROUGH TONIGHT/... VERY MUCH AN ERLY AUG MRNG TDA...BOTH IAD AND APG 12Z SNDGS SHOW A SLTLY WARMING ATMOSPHERE W/ LO LVL MOISTURE. ERLY MRNG LGT FOG HAS TURNED INTO A HAZY MRNG. HIGH PRES OFF THE CST WL KEEP DWPTS IN THE U60S/L70S. HIGH TEMPERATURES WILL AGAIN BE IN THE LM90S. HEAT INDICES COULD EXCEED 100 DEGREES BETWEEN 2 PM AND 5 PM ESPECIALLY IN THE METRO AREAS BUT CONDITIONS SHOULD FALL SHORT OF A HEAT ADVISORY. SHOWERS AND THUNDERSTORMS WILL FIRE UP ALONG THE WESTERN MOUNTAINS BY EARLY AFTERNOON. AN ISOLATED STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE LATER IN THE AFTERNOON AS MOISTURE AND INSTABILITY IS RECIRCULATED. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... THIS WKND CWFA WL BE BTWN HIPRES RDG IN THE WRN ATLC AND A CDFNT/H5 VORTMAX CROSSING THE GRTLKS. THE UPA PTTN FEATURES WLY FLOW MAINLY CONFINED TO THE NRN CONUS...W/ BROAD HIPRES ACRS THE SRN STATES. THAT/LL LEAD TO TYPICAL HEAT AND HUMIDITY...WHICH WL CULMINATE IN LT DAY TSRA. NO BIG CHGS TO TEMP FCSTS...PER MOS CONSISTENCY. SAT ACTIVITY WL FEED OFF OF TRRN CIRCULATIONS...THTE MAX...AND MESOSCALE BNDRYS-- THE LATTER OF WHICH WL BE DFCLT TO PIN DWN FM THIS STANDPOINT. HV BUMPED UP POPS AREAWIDE...AND ATTEMPTED TO ADD A LTL PLACEMENT/TIMING DETAIL NONETHELESS. USED CLIMO A BIT IN TIMING...ORIGINATING TSRA IN MTNS BY ELY AFTN...EVOLVING INTO LEE TROF ELY EVNG...AND THEN PUSHING TWD DELMARVA AFDK. SUN WL BE INFLUENCED MORE BY THE APPCHG BNDRY/UPR TROF...WORKING ON AN UNSTBL AMS. NAM/GFS/ECMWF SEEM TO HV DECENT HANDLE ON TIMING...W/ A SUN NGT CFP. DYNAMICS AND LAPSE RATES PREFERRED N OF CWFA...WHICH IS WHERE THE HIER POPS WERE PLACED. THAT/S NOT TO DISCOUNT STRENGTH OF ACTIVITY W/IN CWFA...AS THERE/S MORE THAN ADEQUATE INSTBY/SHEAR...SPCLY FOR NRN CNTYS. MENTION OF SVR IN HWO WUD APPEAR JUSTIFIED. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PATTERN WL BE DOMINATED BY AN UPPER LVL RDG OVR THE ROCKY MTNS AND SLT TROFFING IN THE ERN U.S. BECAUSE OF THIS THE REALLY HIGH HEAT IS XPCTD TO BE HELD AT BAY THRU THE 1ST WK OF AUG. AFTR THE FNT MOVES THRU...AND THERE`S NO GUARANTEE AT THIS TIME OF THE YR THAT IT WL...UPR TROF SHOULD BE A CONTROLLER. AS MENTIONED ABV TEMPS SHOULD NOT GO MUCH ABV THE CLIMO NORMS...BUT ALMOST ALL SUMMER MDL TEMP FCSTS HV NOT BEEN WARM ENUF. THE FLIP IS THERE WAS ONE TIME THIS SUMMER (THAT I CAN RECALL) WHERE AFTR A FNT WENT THRU WE MOVED INTO A CAD ENVIRONMENT AND TEMPS ACTUALLY WERE BLO NORMS. FOR TIME BEING WL KEEP HIGHS IN U80S/LOWS 65-70. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... CUMULUS CLOUDS BASES FL050 POSSIBLE BY LATE AFTERNOON WITH LESS THAN A 20 PERCENT CHANCE OF A TS AT THE MAJOR TERMINALS THRU 22Z. SFC WINDS 18010KT. THIS CHANCE INCREASES TO 30 PERCENT BETWEEN 22Z AND 03Z...THEN DECREASES OVERNIGHT. FLGT RESTRICTIONS PSBL W/IN MAINLY DIURNAL TSRA SAT AND SUN. CVRG SUN MAY BE TIMED A LTL LATER DUE TO CFP. REDUCTIONS WUD BE BRIEF... POTENTIALLY DOWN TO IFR. ALSO MAY HV ELY MRNG VSBY RESTRICTIONS... MVFR MOST LKLY...THO IFR PSBL INVOF AREAS WHICH RECVD TSRA FM THE PRVS DAY. && .MARINE... SOUTHERLY CHANNELING COULD CAUSE SOME BREEZY AFTERNOON WINDS TODAY BUT EXPECTED TO REMAIN BELOW SCA CONDITIONS. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN THIS AFTERNOON. LOCALLY GUSTY WINDS AND LIGHTNING ARE POSSIBLE NEAR STORMS. SLY CHANNELING PSBL SAT EVNG...AND AGN LT SUN AHD OF CDFNT. POTL SCA FOR EACH OCCASION. ALSO WL HV TSRA DAILY TO CONTEND WITH...ANY OF WHICH MAY CONTAIN GUSTY WINDS. SMW/S PSBL. FROPA EITHER LT SUN OR ELY MON. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ PRODUCTS...WOODY! |
| #531491 (Received by flhurricane at: 10:47 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1030 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...ONLY CHANGE AT THIS TIME WAS TO BUMP POPS UP ALONG A STRIPE OF REAL ESTATE ROUGHLY FOLLOWING THE COAST AND ABOUT 20 MILES INLAND. THERE IS SOME MODEL AGREEMENT THAT THIS WILL BE WHERE CONVECTION FIRES THIS AFTERNOON. THE UPPER LOW WILL PROVIDE COOL AIR ALOFT AND SOME MID LEVEL INSTABILITY BUT NOT REALLY ANY FORCING TO MENTION SINCE IT WILL BARELY BE MOVING. STORM INITIATION THUS SEEMS TO MAINLY BE DRIVEN BY LOW LEVEL PROCESSES WHICH IN THIS CASE WILL BE NOT ONLY THE SEABREEZE BUT ALSO SOME DIFFERENTIAL HEATING ON THE EAST SIDE OF A CLOUD MASS NOW SEE OVER INLAND NC ZONES. SLIGHT CHANCE POPS WILL REMAIN ELSEWHERE DUE TO THE SLIGHTLY COOL MID LEVELS AND ALSO THE PRESENCE OF SOME HARD-TO-DETECT OUTFLOW BOUNDARIES FROM YESTERDAYS CONVECTION. PREVIOUS DISCUSSION: AS OF 700 AM FRIDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA WITH POSSIBLE THUNDER...OVER INLAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE CONTINUED DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND THE MID LEVEL DYNAMICS FROM THE VORT...WILL ALL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...VFR EXPECTED THROUGH VALID PERIOD...WITH EXCEPTION OF POTENTIAL FOG OVERNIGHT INTO SATURDAY. LIGHT AND VARIABLE WINDS THIS MORNING CONTINUE WITH A FEW ISOLATED SHOWERS IN AND AROUND THE AREA AS WELL AS PATCHY FOG. CANNOT RULE OUT CONTINUED ISOLATED -SHRA THIS MORNING BUT DO NOT ANTICIPATE ANY LONG LIVED RESTRICTIONS TO ARISE FROM THIS ACTIVITY. AS VFR PREVAILS...SOUTH-SOUTHEAST WINDS WILL INCREASE TO AOB 10 KTS THROUGHOUT THE DAY WITH MID TO HIGH LEVEL CLOUDS. HAVE INTRODUCED VCTS/VCSH FOR THIS AFTERNOON AND EVENING. CONVECTION WILL BE ISOLATED TO SCATTERED IN NATURE ACROSS THE ENTIRE AREA. CANNOT RULE OUT BRIEF RESTRICTIONS...THOUGH CONFIDENCE IS LOW. INTO THE OVERNIGHT HOURS...VFR WILL PREVAIL WITH WITH WINDS BECOMING LIGHT. POSSIBILITY OF FOG DEVELOPMENT CANNOT BE RULE OUT OVERNIGHT...ESPECIALLY AT THE INLAND SITES. COULD CREATE MVFR/BRIEF IFR/CONDITIONS. AFTER DAYBREAK...FOG WILL DISSIPATE ALLOWING VFR TO PREVAIL WITH SOUTHWEST WINDS AOB 8 KTS. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM FRIDAY...NO CHANGES AT ALL AT THIS TIME. AS OF 700 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WIND DIRECTIONS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531488 (Received by flhurricane at: 10:42 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1036 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHENS OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... STRATUS ALONG THE COAST WILL BURN OFF AS BOUNDARY LAYER HEATS. WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD WITH VFR EXPECTED. THE ONLY EXCEPTION WILL BE SOME EARLY MORNING MVFR OR IFR FOG. ANY SUB-VFR CIGS ARE EXPECTED TO IMPROVE TO VFR BY 13Z-15Z. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IN THE TAFS. WINDS ARE GENERALLY SW UNDER 10 KT THROUGH THE PERIOD. DURING THE AFTERNOON...SEA BREEZES ARE EXPECTED TO SHIFT WINDS MORE SOUTHERLY AND INCREASE SLIGHTLY. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS MORNING OR EARLY THIS AFTERNOON FOR TIMING OF SEABREEZE. OUTLOOK FOR 12Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS....MAINLY IN THE AFTERNOON. LATE DAY TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...NV/DW |
| #531489 (Received by flhurricane at: 10:42 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1031 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHENS OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... STRATUS ALONG THE COAST WILL BURN OFF AS BOUNDARY LAYER HEATS. WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD WITH VFR EXPECTED. THE ONLY EXCEPTION WILL BE SOME EARLY MORNING MVFR OR IFR FOG. ANY SUB-VFR CIGS ARE EXPECTED TO IMPROVE TO VFR BY 13Z-15Z. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE THIS AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IN THE TAFS. WINDS ARE GENERALLY SW UNDER 10 KT THROUGH THE PERIOD. DURING THE AFTERNOON...SEA BREEZES ARE EXPECTED TO SHIFT WINDS MORE SOUTHERLY AND INCREASE SLIGHTLY. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS MORNING OR EARLY THIS AFTERNOON FOR TIMING OF SEABREEZE. OUTLOOK FOR 12Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS....MAINLY IN THE AFTERNOON. LATE DAY TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...MORNING SUB-VFR POSSIBLE IN TSRA/SHRA...THEN IMPROVING. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...NV/DW |
| #531487 (Received by flhurricane at: 10:41 AM 03.Aug.2012) AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 1034 AM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TODAY WITH POSSIBLE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN FOR SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE: LATEST SFC ANALYSIS SHOWED COLD FRONT PUSHING THROUGH QUEBEC. HIGH INSTABILITY WILL BE ACROSS NORTH-CENTRAL AND DOWNEAST AREAS LATER THIS MORNING INTO THE AFTERNOON. WILL NEED TO WATCH THE NERN AREA OF NORTHERN MAINE AND ACROSS THE INTERIOR DOWNEAST THIS AFTERNOON AS THESE AREAS SHOW THE HIGHEST INSTABILITY. WBZS ARE RUNNING ABOVE 11K FT W/PWATS AOA 1.5". 0-6KM SHEAR IS AROUND 25KTS. SB CAPES SHOWN BY THE LATEST NAM/RAP TO HIT 1800-2200 JOULES ACROSS THE AFOREMENTIONED AREAS BY 18Z. LOOKS LIKE A STRONG WIND GUSTS AND HEAVY RAINFALL NOW THE MAIN THREAT. UPDATED THE GRIDS TO REFLECT THIS CHANGE TO ENHANCED WORDING AND REMOVED MENTION OF SMALL HAIL. BROUGHT MAXES UP FOR THIS AFTERNOON ACROSS THE CENTRAL HIGHLANDS TO MID/UPPER 80S AHEAD OF THE FRONT. PREVIOUS DISCUSSION... MAIN FOCUS FOR TODAY WILL BE ON THE NEXT...SOMEWHAT STRONGER COLD FRONT WHICH CURRENTLY XTNDS NE-SW FROM CENTRAL QUEBEC DOWN INTO THE ERN GRT LAKES AND IS STILL EXPECTED TO SWING SEWRD ACROSS THE REGION LATER TODAY. SFC CONVERGENCE ALONG AND IN ADVANCE OF THIS BNDRY WILL INTERACT W/ TDS IN THE MID TO UPPER 60S AND A HEALTHY UPPER SHORT WAVE TO TRIGGER THE THREAT OF SOME CONVECTION ACROSS THE AREA BY LATE AM INTO THE AFTN W/ ACTIVITY WINDING DOWN FROM NW-SE LATER THIS AFTN AS DRIER AIR BEGINS TO WORK INTO THE REGION. WHILE SHEAR VALS NOT VERY IMPRESSIVE...SFC BASED CAPES JUMP UP NR 2000 J/KG ACROSS CENTRAL/E CENTRAL AREAS BY ERLY AFTN SO EXPECT THE THREAT OF AN ISOLD STRONG TO SVR TSTM CAN NOT BE RULED OUT AND WILL CONT ENHANCED WORDING... SIMILAR TO THE LAST FEW DYS...ANY ERLY AM FOG/STRATUS TODAY SHOULD LIFT/BURN OFF RATHER QUICKLY THIS AM W/ OUR COASTAL AREAS BEING THE SLOWEST TO IMPROVE. A MORE SWRLY LOW-LEVEL FLOW SHOULD ALLOW HIGH TEMPS TO REACH THE LOWER TO MID 80S N AND MID TO UPPER 80S S AWAY FROM THE COAST... WHILE DRIER AIR OVERSPREADS THE AREA FROM NW-SE TNGT...CLRG SKIES AND LGT WINDS WILL ALLOW FOR SIGNIFICANT COOLING LIKELY ALLOWING TEMPS TO REACH TDS AND INCREASING THE POTENTIAL FOR SOME FOG AGAIN TNGT. IN THESE SCENARIOS IT IS ALWAYS A RACE BTWN THE DRYING AND COOLING AND WHICH FACTOR WINS OUT. FOR NOW...WILL CARRY PATCHY FOG N AND CENTRAL W/ AREAS DOWNEAST AS THESE WILL BE THE LAST TO SEE THE DRIER AIR... EXPECT LOWS TNGT TO BE SIGNIFICANTLY COOLER THAN THE LAST FEW DYS...AT LEAST FOR OUR CENTRAL AND NRN AREAS W/ LOWS RANGING FROM THE LOWER TO MID 50S N TO THE LOWERS 60S S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... EXPECT THE WEEKEND TO BE MAINLY DRY WITH ABOVE NORMAL TEMPERATURES AS HIGH PRESSURE BUILDS OVER THE REGION. SATURDAY WILL START OUT MOSTLY SUNNY, BUT CLOUDS WILL INCREASE FROM THE SOUTH LATE IN THE DAY AS A WARM FRONT LIFTS NORTHWARD. THIS BOUNDARY WILL MOVE ACROSS THE STATE SATURDAY NIGHT AND MAY PRODUCE A FEW SHOWERS OVER THE HIGHER TERRAIN AS IT DOES SO. MUGGIER AIR WILL SPREAD INTO THE REGION BEHIND THE FRONT WITH A RETURN OF MID 60S DEWPOINTS BY SUNDAY AFTERNOON. A COLD FRONT WILL APPROACH THE REGION FROM QUEBEC SUNDAY AFTERNOON, BUT MOST OF THE PRECIPITATION WILL HOLD OFF UNTIL LATE IN THE DAY, EXCEPT PERHAPS IN FAR WESTERN AREAS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE AFOREMENTIONED COLD FRONT WILL MOVE THROUGH THE STATE LATE SUNDAY NIGHT INTO MONDAY MORNING. THE TIMING OF THE FRONTAL PASSAGE IS NOT OPTIMAL FOR INSTABILITY, THOUGH 0-6 KM SHEAR INCREASES TO AROUND 30 KT JUST AHEAD OF THE FRONT. DOWNEAST AREAS WOULD HAVE THE BEST CHANCES OF SEEING ANY ORGANIZED CONVECTION, AS STORMS WOULD MOST LIKELY BE ELEVATED ACROSS THE NORTH. ALSO OF CONCERN IS INCREASING MOISTURE TRANSPORT AHEAD OF THE FRONT; MODELS ARE INDICATING PWATS OF 2+ INCHES AREAWIDE SUNDAY NIGHT INTO MONDAY MORNING. IN ADDITION, THE WARM CLOUD LAYER LOOKS TO BE DEEP, AROUND 13-14 KFT. THIS MEANS THAT ANY STORMS WOULD BE CAPABLE OF PRODUCING HEAVY RAIN. ONCE THE FRONT GOES BY, HIGH PRESSURE AND DRIER WEATHER RETURNS MONDAY NIGHT AND TUESDAY. THEN ANOTHER COLD FRONT WILL GRADUALLY MOVE SOUTH TUESDAY NIGHT, BECOMING NEARLY STATIONARY NEAR THE SAINT JOHN VALLEY WEDNESDAY BEFORE FINALLY PUSHING SOUTH INTO DOWNEAST MAINE WEDNESDAY NIGHT/THURSDAY. THE LONGER-TERM MODELS ARE SHOWING SOME DIFFERENCES IN TIMING OF THIS FEATURE AND ITS ASSOCIATED PRECIPITATION, SO HAVE STUCK WITH 20-30 POPS FOR MID WEEK. TEMPERATURES WILL BE SEASONABLE THROUGH THE WEEK. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... NEAR TERM: ALL TAF SITES IFR ATTM XCPT KPQI WHICH IS CURRENTLY MVFR. THIS RATHER IRONIC CONSIDERING A TSTM DROPPED SIGNIFICANT RAINFALL ON PQI THU AFTN WHERE MOST OTHER AREAS SO LITTLE OR NO RAINFALL... IN ANY CASE...THINK KPQI WILL JOIN THE REST SHORTLY. IFR CONDS SHOULD THEN PERSIST INTO THE AM HRS SIMILAR TO LAST SEVERAL DAYS W/ KBHB NEAR THE SRN COAST THE SLOWEST TO IMPROVE. DESPITE THE PASSAGE OF A COLD FRONT LATER TODAY AND THE INFLUX OF LOWER TDS...LGT WINDS BEHIND THE FRONT TNGT AND CLR SKIES WILL LEAD TO GOOD COOLING AND WILL LIKELY RESULT IN PATCHY FOG ACROSS THE NRN TAF SITES W/ MORE WDSPRD FOG S... SHORT TERM: VFR IS EXPECTED THROUGH THE WEEKEND, WITH EXCEPTION OF IFR DUE TO PATCHY FOG LATE SATURDAY NIGHT, ESPECIALLY AT THE TERMINALS. A COLD FRONT WILL MOVE ACROSS THE AREA EARLY MONDAY, PRODUCING SHOWERS AND THUNDERSTORMS. WHILE VFR SHOULD PREVAIL THROUGH MIDWEEK, MVFR CONDITIONS ARE POSSIBLE IN ANY PRECIPITATION SUNDAY NIGHT AND MONDAY. && .MARINE... NEAR TERM: WINDS/SEAS SHOULD REMAIN BLO SCA LEVELS THRU TNGT. FOG WILL CONT TO BE AN ISSUE THRU TNGT. SHORT TERM: A SMALL CRAFT ADVISORY MAY BE NEEDED LATE SUNDAY THROUGH MONDAY AS SOUTH WINDS INCREASE AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL BE BORDERLINE /GUSTS AROUND 20 KT/ BUT WAVES LOOK TO REACH 5-6 FT LATE SUNDAY EVENING AND REMAIN SO INTO EARLY MONDAY NIGHT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...HEWITT/KHW |
| #531486 (Received by flhurricane at: 10:02 AM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 953 AM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TODAY AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /TODAY/... AS OF 945 AM FRIDAY...MINOR ADJUSTMENTS WITH THE MORNING UPDATE MAINLY TO REMOVE POPS FOR WESTERN ZONES AS CONVECTION HAS REMAINED JUST WEST OF THE AREA...WITH HRRR AND MESOMODELS KEEPING PRECIP OUT UNTIL THIS AFTERNOON. MINOR TWEAKS TO TEMPS/DEWPOINTS WITH TEMPS REBOUNDING SLIGHTLY FASTER THAN FORECAST DUE TO LACK OF CLOUD COVER AND FULL INSOLATION...STILL EXPECT LOWS IN THE LOWER 90S INLAND TODAY. WEAK UPPER LEVEL LOW TO THE SOUTH WILL GRADUALLY LIFT OUT TO THE NORTH TODAY. 500 MB ANALYSIS INDICATES -10 C AT 00Z AND GIVEN THIS RATHER COLD AIR ALOFT AND SOME MODERATE SURFACE BASED INSTABILITY THIS AFTERNOON WITH CAPES IN THE 1000 TO 1500 J/KG RANGE AND LIFTED INDICES OF -4 TO -6 C...WILL FORECAST ISOLATED TSTMS ALONG INLAND AREAS ASSOCIATED WITH THE SEA BREEZE. MAX TEMPERATURES AREA-WIDE SHOULD BE IN THE UPPER 80S TO LOWER 90S. && .SHORT TERM /TONIGHT/... AS OF 315 AM FRIDAY...THE UPPER AIR PATTERN STARTS TO CHANGE BY LATER TONIGHT AS H5 RIDGE NEAR BERMUDA STARTS TO BUILD WEST WITH STEADY HEIGHT RISES INDICATED OVERNIGHT. ANY CONVECTION SHOULD SHIFT FROM THE LAND TO THE COASTAL AREAS AND OFFSHORE WATERS AND WILL HAVE A SLIGHT CHANCE OVERNIGHT. MINIMUM TEMPERATURES TONIGHT GENERALLY FROM 73 TO 78 DEGREES ACROSS THE REGION. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 245 AM FRI...CONTINUED WITH LITTLE CHANGES TO THE FORECAST OR FORECAST REASONING THROUGH THE LONG TERM. HIGH PRESSURE ALOFT WILL CONTINUE TO EXTEND INTO THE AREA FROM THE WESTERN ATLANTIC THROUGH THE WEEKEND. THE BERMUDA HIGH ALSO STRENGTHENS OFFSHORE ALLOWING MOIST SOUTHERLY FLOW TO CONTINUE THROUGH THE EXTENDED. EXPECT ISOLATED TO SCATTERED DIURNAL CONVECTION INLAND AND ALONG THE SEA BREEZE BOUNDARY THROUGH THE WEEKEND. LOW LEVEL THICKNESSES WILL PERSIST AT 1415-1420 METERS...YIELDING TEMPS NEAR CLIMATOLOGY WITH HIGHS IN THE LOW/MID 90S INLAND TO 80S ALONG THE COAST. A FRONTAL BOUNDARY IS PROGGED TO APPROACH THE AREA FROM THE NORTHWEST MON WITH MOIST SOUTHWESTERLY FLOW AND INCREASING LOW LEVEL SHEAR AHEAD OF A ROBUST MID LEVEL SHORTWAVE. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE MON AFTERNOON/EVENING WITH PWATS AGAIN BUILDING ABOVE 2 INCHES. 12Z OPERATIONAL ECMWF AND GFS INDICATE THE FRONT WILL STALL JUST WEST OF THE REGION ACROSS THE CENTRAL PIEDMONT AND MID ATLANTIC STATES LATE MON THROUGH THURS WHILE AN UPPER TROUGH BECOME RE-ESTABLISHED ACROSS THE EASTERN CONUS. 00Z/12Z ECMWF SUGGEST A WEAK SURFACE LOW WILL FORM ALONG THE FRONT TUES NIGHT AND PUSH NE OFF THE MID ATLANTIC COAST WED INTO WED NIGHT. WILL MAINTAIN CHANCE POPS TUES THROUGH THURS WITH THE UPPER TROUGH AND STALLED SURFACE FRONT CONTINUING ACROSS THE REGION WHILE WEAK SHORTWAVES MOVE THROUGH THE FLOW ALOFT. LOW LEVEL THICKNESSES WILL REMAIN AROUND 1415 METERS MON THROUGH THURS HOWEVER GREATER CLOUD COVER AND PRECIP MAY MODERATE TEMPS FROM REACHING ABOVE THE 90 DEGREE MARK EACH DAY. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 06Z SATURDAY/... AS OF 650 AM FRIDAY...FOG AND STRATUS HAS FAILED TO MATERIALIZE THIS MORNING WITH THE EXCEPTION OF SOME 4 MILE VSBYS AT KOAJ. THIS FOG...AND ANY FOG THAT DEVELOPS AT THE OTHER TAF SITES...SHOULD DISSIPATE QUICKLY WITH VFR CONDITIONS EXPECTED THROUGH TODAY AND INTO TONIGHT. LONG TERM /SATURDAY THROUGH TUESDAY/ AS OF 245 AM FRI...PREDOMINANT VFR AVIATION CONDITIONS EXPECTED THROUGH THE EXTENDED. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN DIURNAL CONVECTION EACH DAY. SOUTHWESTERLY SURFACE FLOW WILL PERSIST INTO EARLY NEXT WEEK WITH HIGH PRESSURE ANCHORED OFFSHORE. A FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST MON NIGHT INTO TUES WITH SHOWERS AND THUNDERSTORMS EXPECTED AHEAD OF AND ALONG THE BOUNDARY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 950 AM FRIDAY...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE LIGHT SE BREEZE 4-8 KNOTS WITH MEDIUM PERIOD SWELLS 2-3 FEET AT 8-9 SECONDS. A LIGHT S/SW WINDS AT 10 KNOTS OR LESS WITH A GENTLE SOUTHEAST SWELL COMPONENT WILL MAKE FOR ANOTHER 24 HOURS OF BENIGN MARINE CONDITIONS TODAY AND TONIGHT. WAVEWATCH AND LOCAL SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TODAY AND TONIGHT AND WINDS WILL GENERALLY NOT EXCEED ABOUT 10 OR 12 KNOTS FROM THE SOUTH TO SOUTHWEST THROUGH EARLY SATURDAY MORNING. LONG TERM /SATURDAY THROUGH TUESDAY/ AS OF 245 AM FRI...GOOD BOATING CONDITIONS EXPECTED SAT AND SUN WITH THE BERMUDA HIGH STRENGTHENING OVER THE WESTERN ATLANTIC BRINGING SLY WINDS ACROSS THE WATERS. SPEEDS WILL RANGE GENERALLY 10-15 KNOTS WITH SEAS 2 TO 3 FT. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THE WEEKEND AS WELL. GRADIENT BEGINS TO TIGHTEN LATE SUN AND MON AS FRONTAL SYSTEM APPROACHES FROM THE NW AND EXPECT WINDS TO INCREASE TO AROUND 15-20 KT...MAINLY ACROSS THE NORTHERN AND CENTRAL WATERS. SWAN/WAVEWATCH HAVE BACKED OFF SLIGHTLY WITH SEAS EARLY NEXT WEEK...NOW ONLY BUILDING ABOUT A FOOT OR SO...UP TO 4 FT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...CTC |
| #531485 (Received by flhurricane at: 9:51 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 947 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHENS OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... STRATUS ALONG THE COAST WILL BURN OFF AS BOUNDARY LAYER HEATS. WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR THROUGH THE TAF PERIOD. THE ONLY EXCEPTION WILL BE SOME MVFR OR IFR FOG. ANY SUB-VFR CIGS ARE EXPECTED TO IMPROVE TO VFR BY 1300Z-1330Z. WINDS ARE GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IN THE TAFS. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. GENERALLY LOOKING AT ANOTHER VFR NIGHT...HOWEVER ANOTHER NIGHT OF PATCHY FOG MAY LOWER VSBYS DOWN TO MVFR OR IFR CONDITIONS...MAINLY LATE IN THE TAF PERIOD. WILL LEAVE ANY FOG OUT OF THE TAFS FOR NOW WITH LOW CONFIDENCE OF TIMING AND PLACEMENT OF FOG TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS MORNING OR EARLY THIS AFTERNOON FOR TIMING OF SEABREEZE. OUTLOOK FOR 12Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...NV/DW |
| #531484 (Received by flhurricane at: 9:50 AM 03.Aug.2012) AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 948 AM EDT FRI AUG 3 2012 .UPDATE... RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A WEAKNESS WITHIN THE RIDGE AXIS DUE TO AN UPPER TROUGH EXTENDING SOUTH FROM A WEAK UPPER LOW NEAR THE CAROLINA COAST. THE EARLY MORNING UPPER-AIR SOUNDING AT MIAMI INDICATED THIS WITH PRIMARILY WNW WINDS ALOFT. THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING NORTH-NORTHEAST OVER THE BAHAMAS WITH MOST OF THE SHOWER/TSTM COVERAGE REMAINING JUST EAST OF THE AXIS. THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS SURFACE TROUGH JUST EAST OF THE LOCAL AREA AND GENERALLY INDICATES IT CONTINUING WESTWARD OVER SOUTH FLORIDA THROUGH THE DAY SATURDAY. AS A RESULT...WILL LIKELY SLIGHTLY ADJUST THE RAINFALL CHANCES UP THROUGH THIS TIME SATURDAY IN THE AFTERNOON FORECAST PACKAGE. OTHERWISE...NO CHANGES WERE NECESSARY TO THE PREVIOUS PACKAGE. 85/AG && .PREV DISCUSSION... /ISSUED 724 AM EDT FRI AUG 3 2012/ AVIATION...VFR WILL PREVAIL UNTIL SCATTERED TSRA DEVELOPS THIS AFTERNOON. SO HAVE VCTS ALL SITES. MORNING SHOWERS COULD MOVE ONSHORE THE ATLANTIC COAST THIS MORNING. MVFR OR IFR IS POSSIBLE WITH THE AFTERNOON TSRA, BUT THOSE CONDITIONS WOULD BE BRIEF. LIGHT WINDS WILL BECOME ONSHORE NEAR 10 KT THIS AFTERNOON. DG/KOB PREV DISCUSSION... /ISSUED 359 AM EDT FRI AUG 3 2012/ LONG TERM...MONDAY THROUGH THURSDAY...THE CHANCE OF RAIN TAPERS DOWNWARD FROM MIDWEEK ON AS THE ATLC HIGH CENTER MOVES WESTWARD PULLING SOME DRIER AIR OVER S FLA. A DEEP EASTERLY WIND FLOW DICTATES THAT THE HIGHER POPS WILL BE IN THE W INTERIOR AND W COAST AS HURRICANE ERNESTO APPROACHES THE YUCATAN PENINSULA BY MID WEEK. AS ERNESTO TRACKS WESTWARD...AT THIS TIME...THE ONLY EFFECT TO S FLA WILL BE AN INCREASE IN THE LOW LEVEL EASTERLY WINDS FROM MIDWEEK ON. BUT KEEP AWARE OF NHC FORECASTS OF THE DEVELOPMENT AND FORECAST MOVEMENT OF THIS STORM. MARINE...AT THIS TIME...EASTERLY WINDS WILL BE BELOW 15 KNOTS WITH SEAS 3 FEET OR LESS TODAY AND THROUGH THE WEEKEND. WINDS AND SEAS WILL BEGIN TO INCREASE EARLY NEXT WEEK BUT AT THIS TIME NO HIGHLIGHTS ARE EXPECTED. FIRE WEATHER...NO CONCERNS AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 91 79 89 77 / 30 30 50 40 FORT LAUDERDALE 91 79 89 79 / 30 30 50 40 MIAMI 91 78 90 79 / 30 30 50 40 NAPLES 90 77 91 77 / 30 20 50 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ |
| #531483 (Received by flhurricane at: 9:41 AM 03.Aug.2012) AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 937 AM EDT FRI AUG 3 2012 .SYNOPSIS... BERMUDA HIGH PRESSURE WILL INFLUENCE OUR WEATHER THROUGH SUNDAY. A COLD FRONT WILL CROSS THE AREA SUNDAY NIGHT AND EARLY MONDAY. THIS FRONT WILL REMAIN TO THE SOUTH OF THE REGION WHILE ANOTHER HIGH PRESSURE SYSTEM BUILDS IN FROM THE NORTH THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... OVERALL A FAIRLY QUIET DAY EXPECTED TODAY. A WEAK COLD FRONT WILL BE MOVING THROUGH THE GREAT LAKES, BUT WILL LIKELY NOT MAKE IT MUCH FARTHER THAN CENTRAL NEW YORK/PENNSYLVANIA THIS AFTERNOON BEFORE STALLING OUT. HIGH PRESSURE SLIGHTLY BULGING INTO THE AREA FROM OVER THE OCEAN WILL CONTINUE TO KEEP US IN A GENERAL SOUTH- SOUTHWESTERLY FLOW. THICKNESSES WILL INCREASE TODAY, AND WITH 850 MB TEMPERATURES IN THE MID-UPPER TEENS, WE EXPECT TEMPERATURES TO TOP OUT IN THE LOW 90S. THE DEW POINTS MAY DROP A LITTLE DURING THE DAY, BUT WE STILL EXPECT HEAT INDEXES IN THE PHILLY METRO AREA TO TOP OUT AROUND 100 DEGREES. A HEAT ADVISORY IS ALREADY IN PLACE, SO WE WILL KEEP IT AS IS FOR NOW. THE REST OF THE AREA SHOULD REMAIN BELOW THEIR ADVISORY CRITERIA, SO WE LEFT THEM OUT. WITH THE FRONT EXPECTED TO REMAIN TO OUR NORTH, AND NO STRONG SHORT WAVE/VORT MAXES EXPECTED, WIDESPREAD CONVECTION IS NOT ANTICIPATED TODAY. HOWEVER, WITH PWATS AROUND 1.5 INCHES AND A FAIR AMOUNT OF INSTABILITY DURING THE DAY /CAPES AROUND 1,500 J/KG; LI`S AROUND -4/ WE COULD HAVE SOME INSTABILITY TYPE SHOWERS/THUNDERSTORMS DEVELOP. ANYTHING THAT DOES DEVELOP IS EXPECTED TO BE ISOLATED, SO WE WILL ONLY HAVE POPS AROUND 20 PERCENT THIS AFTERNOON. UPDATED BASED ON CURRENT TEMPERATURES AND TRENDS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... IF ANY SHOWERS/THUNDERSTORMS DO DEVELOP THIS AFTERNOON, THEY SHOULD DIMINISH QUICKLY AFTER SUNSET. THERE IS SOME WEAK MID-LEVEL VORTICITY FORECAST OVERNIGHT, BUT THIS MAY ONLY BRING AN INCREASE IN CLOUD COVER OVERNIGHT. THERE IS THE POSSIBILITY FOR SOME LIGHT FOG TO DEVELOP OVERNIGHT FRIDAY INTO SATURDAY MORNING, BUT CONFIDENCE IN OCCURRENCE AND HOW THICK IT WOULD BE IS LOW, SO WE WILL NOT INCLUDE IT AT THIS TIME. OVERNIGHT LOWS WILL REMAIN ABOVE AVERAGE; A BLEND OF MAV/MET MOS WAS TAKEN. && .LONG TERM /SATURDAY THROUGH THURSDAY/... THE RATHER HOT AND HUMID CONDITIONS WILL CONTINUE THIS WEEKEND AS THE HIGH PRESSURE OFF THE EAST COAST CONTINUES TO BRING A SRLY FLOW OF SUMMER-LIKE WARMTH TO THE AREA. TEMPERATURES WILL LIKELY BE IN THE UPPER 80S TO LOW 90S ACROSS THE AREA...LOWER THAN FRI. I WILL NOT EXTEND THE HEAT ADVISORY INTO SAT AT THIS TIME...WITH CONFID IN TEMPERATURES/CLOUD COVER FOR SAT LOW AT THIS POINT. LOW PRESSURE AND A PROGRESSIVE UPPER SHORT WAVE OVER THE UPPER GREAT LAKES SATURDAY WILL MOVE EAST AND ARRIVE ACROSS NEW ENGLAND AND THE MIDDLE ATLANTIC SUNDAY NIGHT AND MONDAY. THIS WILL BRING INCREASED CHANCES FOR SHOWERS AND TSTMS. THE SPC HAS OUTLOOKED THE AREA FOR A SLGT CHC FOR SVR WEATHER ON SUN/SUN NIGHT. THE FRONT WILL SETTLE TO THE SOUTH OF THE AREA MON NIGHT/TUE. THIS WILL ALLOW HIGH PRESSURE TO BUILD IN FROM THE NORTH. TEMPERATURES TUE-THU WILL BE A LITTLE COOLER THAN THE WEEKEND WITH MOSTLY MID OR UPPER 80S...STILL ABOVE NORMAL. HUMIDITY LEVELS SHOULD BE LOWER THAN THEY WILL BE THIS WEEKEND. A CHC FOR A FEW SHOWERS/TSTMS WILL BE ACROSS THE AREA WED AS A WEAK SHORTWAVE MOVES ALONG THE STALLED FRONT TO THE SOUTH AND BRINGS INCREASED MOISTURE TO THE AREA. SLGT CHC/CHC POPS IN THE GRIDS FOR NOW. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. MOST OF THE EARLY MORNING FOG HAS CLEARED OUT WITH ONLY KTTN STILL EXPERIENCING LOWER VISIBILITIES AND CEILINGS. THE REMAINING FOG SHOULD CLEAR OUT OVER THE NEXT HOUR. OTHERWISE, VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE DAY. MORNING CIRRUS SHOULD BE REPLACED BY SCT-BKN CLOUDS AROUND 5,000 FEET. THERE IS THE POSSIBILITY OF SOME ISOLATED SHOWERS/THUNDERSTORMS THIS AFTERNOON, BUT THE CONFIDENCE AND COVERAGE IS SMALL ENOUGH NOT TO INCLUDE IN THE TAFS AT THIS TIME. WIND ARE EXPECTED TO REMAIN OUT OF THE SOUTH-SOUTHWEST AND GENERALLY LESS THAN 10 KNOTS. VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO THE EVENING HOURS, BEFORE THE POSSIBILITY OF OVERNIGHT/MORNING MVFR FOG DEVELOPMENT FRIDAY NIGHT INTO SATURDAY MORNING. WINDS WILL LIKELY BECOME LIGHT AND VARIABLE MOST PLACES OVERNIGHT; IF THERE IS ANY WIND IT IS EXPECTED TO BE LIGHT AND OUT OF THE SOUTH-SOUTHEAST. OUTLOOK... SAT AND SAT NIGHT...VFR. SUN THRU MON...VFR MOST OF THE TIME...BUT AREAS OF SHOWERS/TSTMS SUN AFTERNOON AND NIGHT WILL BRING TIMES OF LOWER CIGS/VSBYS. MON THRU TUE...MOSTLY VFR. SCATTERED SHOWERS EARLY MON. && .MARINE... CONDITIONS ON THE WATERS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS THROUGH FRIDAY NIGHT. WINDS MAY PERIODICALLY GUST AROUND 20 KNOTS, ESPECIALLY EARLY THIS MORNING AND LATER TODAY INTO THE EVENING. OUTLOOK... SUB-SCA CONDITIONS SAT AND SAT NIGHT...BUT THEN AN INCREASING SRLY FLOW WILL BRING SCA CONDITIONS TO THE WATERS FOR SUN INTO MON. AREAS OF SHOWERS/TSTMS ON SUN-MON MAY BRING GUTSY WINDS AND LOCALLY HAZARDOUS CONDITIONS. WINDS AND SEAS WILL SETTLE BACK BELOW SCA CONDITIONS BY TUE. && .RIP CURRENTS... THE MODERATE RISK FOR RIP CURRENTS WAS KEPT FOR NEW JERSEY, AND LOW FOR DELAWARE. NOT MUCH OF A CHANGE IN CONDITIONS FROM YESTERDAY, EXCEPT WE ARE MOVING FURTHER AWAY FROM THE FULL MOON. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ067>071. NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ015-017>019. DE...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR DEZ001. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...MEOLA/O`HARA |
| #531482 (Received by flhurricane at: 9:41 AM 03.Aug.2012) AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 400 AM HST FRI AUG 3 2012 .SYNOPSIS... MODERATE TRADE WINDS WILL PREVAIL AT LEAST THROUGH EARLY NEXT WEEK. CONDITIONS WILL REMAIN ON THE DRY SIDE OF AVERAGE...WITH MOST SHOWERS LIMITED TO WINDWARD SLOPES...OR TO LEE SLOPES OF THE BIG ISLAND IN THE AFTERNOON. && .DISCUSSION... OBSERVATIONS AROUND THE MAIN HAWAIIAN ISLANDS STILL REPORTED LIGHT TO MODERATE TRADE WINDS. PRESSURE TRENDS CONTINUED TO SUPPORT THIS IMPRESSION...AND SUGGESTED LITTLE OR NO CHANGE THROUGH THE SHORT RUN. ALTHOUGH THE AIR MASS IN PLACE OVER THE STATE HELD MOISTURE AT OR ABOVE CLIMATOLOGY FOR THIS TYPICALLY HUMID MONTH...A LOW INVERSION SUBSTANTIALLY SUPPRESSED SHOWER DEVELOPMENT. ACTUALLY... SATELLITE ESTIMATES SHOWED A STREAM OF QUITE DRY AIR TO THE SOUTHEAST OF THE BIG ISLAND...BUT THE TRADE WINDS SHOULD KEEP THE TRAJECTORY OF THAT AIR MASS TO THE SOUTH OF THE STATE THROUGH THE SHORT RUN...AND MODEL CONSENSUS PREDICTS LITTLE FURTHER CHANGE THROUGH THE MIDDLE OF NEXT WEEK. ALOFT...STRONG RIDGING PREVAILED IMMEDIATELY SOUTH OF AND OVER THE ISLANDS...BUT FAIRLY DEEP TROUGHING TO THE NORTH. GUIDANCE SUGGESTS SOME WEAKENING OF BOTH THROUGH THE FORECAST PERIOD...BUT LITTLE CHANGE IN THE OVERALL PATTERN. THUS...SUBSIDENCE THROUGH A DEEP LAYER SHOULD CONTINUE TO SUPPORT A LOWERED INVERSION. GUIDANCE PREDICTED A LOW OR TROUGH TO DEVELOP SOUTHEAST OF MIDWAY ISLAND ON OR AROUND SATURDAY. CONDITIONS THERE WILL NOT BE WELL SUITED FOR THE DEVELOPMENT OF A TROPICAL CYCLONE AS SUCH...BUT IF THE LOW DEEPENS AS MUCH AS GUIDANCE PREDICTS...THEN IT WILL PRODUCE LARGE AREAS OF LOCALLY STRONG WINDS AND HEAVY RAIN ANYWAY. FOR NOW...THIS FEATURE IS NOT EXPECTED TO APPROACH...OR EVEN MOVE TOWARD...THE MAIN HAWAIIAN ISLANDS. HOWEVER...THE DIRECTION AND SPEED OF THE TRADE WINDS LIKELY WILL BE AFFECTED SOMEWHAT BY SUCH A SIGNIFICANT FEATURE DOWNWIND. ALSO...CIRRUS LAYERS FROM THE ACTIVITY RELATED TO THE LOW WILL PASS OVER THE STATE AT TIMES...STARTING AS EARLY AS TODAY. OTHERWISE...CLIMATOLOGY WILL PREVAIL. CONDITIONS WILL REMAIN MAINLY ON THE DRY SIDE...BUT THE HUMID AUGUST AIR MASS WILL SUPPORT LOCALLY STRONGER SHOWERS IF THE INVERSION WEAKENS FOR ANY REASON. THE GENERALLY DRY WEATHER...LEEWARD AT LEAST...LIKELY WILL CARRY A KEY INDEX FOR FIRE WEATHER OVER AN IMPORTANT THRESHOLD WITHIN THE NEXT DAY OR SO. AFTERWARD...UNTIL SIGNIFICANT RAIN FALLS...ANY PERIOD OF MODERATELY STRONG WINDS WITH LOW HUMIDITY COULD POTENTIALLY CREATE THE RISK OF EXTREME FIRE BEHAVIOR...REQUIRING A RED FLAG WARNING. THESE CONDITIONS ARE NEITHER IMMINENT NOR EXPECTED...BUT WILL REQUIRE CONSIDERATION...LIKELY UNTIL THE WINTER RAINY SEASON BEGINS SOMETIME THIS FALL. && .MARINE... NO SIGNIFICANT SWELLS ARE EXPECTED TO REACH THE STATE THROUGH THE FORECAST PERIOD. WINDS SHOULD REMAIN JUST BELOW THE THRESHOLD FOR A SMALL CRAFT ADVISORY IN THE WINDIER MARINE ZONES THROUGH AT LEAST EARLY NEXT WEEK. && .HFO WATCHES/WARNINGS/ADVISORIES... NONE. && $$ |
| #531481 (Received by flhurricane at: 9:41 AM 03.Aug.2012) AFDKEY AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS NATIONAL WEATHER SERVICE KEY WEST FL 931 AM EDT FRI AUG 3 2012 .DISCUSSION... .CURRENTLY... THE HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL STORM ERNESTO WHICH AT THIS POINT THERE IS STILL UNCERTAINTY ON THE DEVELOPMENT OF THE STORM. THE INITIAL RUNS SUGGEST MORE MOISTURE AND HIGHER WINDS DUE TO THE PRESSURE GRADIENT AS ERNESTO PASSES SOUTH OF CUBA AND OVER THE YUCATAN PENINSULA. WILL KEEP VIGILANCE OF THE EVOLUTION OF THE STORM AND UPDATE FORECASTS IF NEEDED. SHOWERS OVERNIGHT ALONG THE LOWER KEYS PRODUCED RAINFALL AMOUNTS ANYWHERE FROM 0.16 INCHES AT THE KEY WEST ASOS...TO 0.23 AT THE WHITE STREET OFFICE...1.6 INCHES FROM A GAGE ALONG THE CAROLINE AND EATON STREET CORRIDOR WHICH MATCHES RADAR ESTIMATES ALONG THE WEST AND NORTHWEST END OF KEY WEST. .FORECAST... A FEW BOUNDARIES FROM OVERNIGHT ACTIVITY ARE LINGERING AROUND THE AREA PRODUCING ISOLATED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE THIS AFTERNOON AND EVENING AS A WEAK INVERTED TROUGH NEARS THE KEYS AREA. THIS WILL TURN THE LIGHT WIND FLOW TO THE EAST NORTHEAST WHICH IS FAVORABLE FOR ISLAND CLOUD LINES. THESE SHOULD INTERACT WITH THE SEA BREEZE BOUNDARIES MOVING OFF THE SOUTHERN PENINSULA AND PROVIDE ADDITIONAL LIFTING AND A CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. A WEAK TROUGH WILL MOVE ACROSS THE AREA THIS WEEKEND WITH SOME DEEP MOISTURE ALONG THE TROUGH. THIS MOISTURE WILL DIMINISH QUICKLY WITH THE PASSING OF THE TROUGH BUT WILL KEEP THE RAIN CHANCES A BIT HIGHER THAN CLIMATOLOGY DUE TO THE CYCLONIC LIFTING IN THE LOWER LEVELS. && .MARINE... LIGHT EASTERLY WINDS ARE EXPECTED TO CONTINUE THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND THUNDERSTORMS. WE ARE KEEPING VIGILANCE ON TROPICAL STORM ERNESTO AND EXPECT AS THE STORM PASSES WELL SOUTH OF CUBA THAT THE MAIN IMPACT WILL BE HIGHER WINDS DUE TO THE INCREASED PRESSURE GRADIENT. IT IS POSSIBLE THAT A CAUTIONARY STATEMENT WILL BE ISSUED FOR PARTS OF THE STRAITS SUNDAY NIGHT THROUGH TUESDAY. WE WILL UPDATE THE FORECAST AS NEEDED DUE TO UNCERTAINTY IN THE FORECAST PATH AND INTENSITY OF ERNESTO. && .AVIATION... CONDITIONS SHOULD MOSTLY BE VFR AT MTH AND EYW TODAY...THOUGH THERE IS A HEALTHY CHANCE FOR CLOUD LINE THUNDERSTORM DEVELOPMENT ALONG THE ISLAND CHAIN...MAINLY AFTER NOON AND BEFORE 700 PM. OTHERWISE LIGHT BREEZES WILL MAINLY BE OUT OF THE EAST...BUT WILL BE VARIABLE AT TIMES. && .CLIMATE... ON THIS DATE IN 1890...THE RECORD COOL MAX TEMPERATURE AT KEY WEST FOR THE MONTH OF AUGUST OCCURRED FOR THE FIRST TIME IN THE RECORD...AT ONLY 81 DEGREES. THIS WAS THE FIRST OF ONLY 11 TIMES WE HAVE FAILED TO REACH 82 DEGREES ON ANY DAY IN AUGUST SINCE RECORDS BEGAN IN KEY WEST. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...NONE. GM...NONE. && $$ |
| #531480 (Received by flhurricane at: 9:29 AM 03.Aug.2012) AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 821 AM CDT FRI AUG 3 2012 .UPDATE... ...SOUNDING DISCUSSION... NO PROBLEMS WITH THE FLIGHT THIS MORNING. PW VALUES ARE UP SLIGHTLY TO 2.15 INCHES WITH A LARGE AMOUNT OF CAPE IN THE COLUMN. A POCKET OF DRIER AIR REMAINS IN THE MID LEVELS THIS MORNING WITH THE SURFACE WINDS REMAINING LIGHT WITH HIGH PRESSURE REMAINING IN CONTROL. ANY THUNDERSTORMS THAT DEVELOP WILL HAVE THE POSSIBILITY OF BECOMING STRONG WITH WIND GUSTS OF 35 TO 40 MPH AND SMALL HAIL POSSIBLE. 98/SO && .PREV DISCUSSION... /ISSUED 405 AM CDT FRI AUG 3 2012/ SHORT TERM... UPPER LEVEL RIDGE TO THE WEST OF THE AREA CONTINUES TO BE THE CONTROLLING FACTOR FOR LOCAL CONDITIONS. TEMPERATURES AND DEWPOINTS ARE IN GENERAL ABOUT A DEGREE OR SO COOLER AREAWIDE. LOOKING UPSTREAM...NOT MUCH IN THE WAY OF THICK CLOUD COVER AS WHAT OCCURRED YSTRDY. SO NOT THINKING THAT HIGHS WILL BE LIMITED AS MUCH AND SHOULD REACH CLOSER TO FCST. HAVE BUMPED UP TD/S FROM GUIDANCE DUE TO ITS LOW BIAS ALL WEEK LONG. COMBINATION OF T/TD WILL ONCE AGAIN BRING HEAT INDICIES RIGHT TO 100 TO 105 RANGE. HAVE QUITE WIDE RANGE IN GUIDANCE ON POPS TODAY. MAV IS ON THE DRIER SIDE WITH GENERALLY 20 PERCENT ACROSS THE AREA. MET/NAM IS MUCH HIGHER AT 50 TO 60 PERCENT AND ECMWF IS AROUND 40. MET/NAM JUST SEEMS TO BE WAY TO AGGRESSIVE...ESPECIALLY WHEN CONSIDERING HOW LITTLE CONVECTION HAS ACTUALLY DEVELOPED OVER THE LAST FEW DAYS. REALLY DONT SEE MUCH IN THE WAY OF A SIGNIFICANT SHORTWAVE NORTH OF THE AREA TO PRODUCE WIDESPREAD DEVELOPMENT. WHAT WILL MORE THAN LIKELY OCCUR IS JUST A FEW STORMS DEVELOPING ALONG SEA BREEZE AND OTHER BOUNDARIES LEFT OVER FROM YSTRDY. SO HAVE GONE WITH THE DRIER MAV FOR POPS TODAY. PROBABLY WILL BE JUST AS UNSTABLE AS YESTERDAY AND A FEW STRONG STORMS WITH SMALL HAIL ARE POSSIBLE. LONG TERM... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH DIGGING INTO THE PACIFIC NORTHWEST THIS MORNING. THIS SYSTEM IS EXPECTED TO SWIFTLY TRACK ACROSS THE NORTHERN HALF OF THE COUNTRY...REACHING THE UPPER MISSISSIPPI VALLEY BY LATE SATURDAY. THIS WILL SUBSTANTIALLY COMPRESS THE RIDGE OVER OUR AREA. SO ITS NO SURPRISE THAT CONVECTION WILL BE ON THE INCREASE THIS WEEKEND WITH LESS SUBSIDENCE. FOR NOW MAINTAINED PREVIOUS FCST POPS ON SATURDAY AT 30 TO 40 PCT BUT DID INCREASE SUNDAY TO 50 PCT COVERAGE WHICH MAY BE A LITTLE CONSERVATIVE. EARLIER NEXT WEEK...A WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE PROGRESSIVE UPPER TROUGH WILL SAG TOWARDS THE CWA. IT WILL BE THE FOCUS FOR CONTINUED INCREASED DAILY CONVECTION. REGARDING TROPICAL STORM ERNESTO...THE STORM IS STILL UNDER THE INFLUENCE OF QUITE A BIT OF SHEAR AND IT STRUGGLING TO MAINTAIN CONVECTION AROUND THE CENTER OF CIRCULATION. THE SHEAR IS EXPECTED TO BE MUCH LESS IN ABOUT 2 DAYS. FROM THAT POINT THE STORM WILL BE IN MORE FAVORABLE CONDITIONS FOR STRENGTHENING OR EVEN JUST REDEVELOPMENT IF IT CONTINUES TO WEAKEN OVER THE NEXT COUPLE DAYS. THE STRENGTH OF THIS STORM WILL BE A MORE IMPORTANT FACTOR IN ITS LONG TERM TRACK. WEAKER SYSTEM WOULD TEND TO STAY FURTHER SOUTH ON A MORE WESTERLY TRACK. STRONGER SYSTEM WOULD LIKELY FEEL THE WEAKNESS IN THE RIDGE TO THE NORTH AND WANT TO STEER ON A MORE WNW TRACK. WHATEVER IT MAY BE...THE SYSTEM SHOULD BE NEAR THE WESTERN CARRIBEAN BY EARLY TO MID NEXT WEEK. MEFFER AVIATION... MAINLY VFR CONDITIONS WILL CONTINUE TO PREVAIL AT THE TAF SITES THROUGH 12Z SATURDAY. ISOLATED TO SCATTERED CONVECTION MAY IMPACT THE TERMINALS IN THE EASTERN HALF OF THE FORECAST AREA THIS AFTERNOON. 11 $$ |
| #531479 (Received by flhurricane at: 9:29 AM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 927 AM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL APPROACH NEW ENGLAND FROM THE NORTHWEST TODAY, THEN STALL ACROSS THE AREA TONIGHT BEFORE RETURNING NORTH AS A WARM FRONT ON SATURDAY. VERY MUGGY CONDITIONS ARE EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION LATE SUNDAY NIGHT OR MONDAY BRINGING WITH IT THE LIKELIHOOD OF SHOWERS AND STORMS. DRIER AIR THEN RETURNS IN THE WAKE OF THE FRONT MONDAY AFTERNOON INTO MIDWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ---1315Z UPDATE--- ANOTHER DAY WITH DEWPOINTS IN THE 60S. WARM AIR ADVECTION AHEAD OF AN APPROACHING FRONT WILL ALLOW SURFACE TEMPERATURES TO CLIMB INTO THE UPPER 80S TO 90S. COMBINATION OF SUNSHINE AND APPROACHING FRONT WILL GENERATE SOME MODERATELY STRONG THUNDERSTORMS THIS AFTERNOON. EXPECT CONVECTION TO INITIATE OVER THE MOUNTAINS AND THEN POSSIBLY ADVECT ONTO THE COASTAL PLAIN. SOME MARGINALLY SEVERE STORMS MAY BE POSSIBLE THIS AFTERNOON AS SBCAPE VALUES APPROACH 2500J/KG. HAVE UPDATED FORECAST TO MAKE MINOR ADJUSTMENTS TO ACCOUNT FOR CURRENT CONDITIONS. 625 AM...MINOR UPDATE FOR 1ST PERIOD HOURLY TEMPS. PREV DISC...WIDESPREAD FOG WAS FORMING IN HUMID AIRMASS CURRENTLY FOUND ACROSS THE FORECAST AREA. AT 06Z...GOES WATER VAPOR IMAGERY SHOWED SHORT WAVE RACING EASTWARD ACROSS THE EASTERN GREAT LAKES. LOW CLOUD AND FOG BURNS OFF QUICKLY THIS MORNING...WITH SOUTHWEST FLOW AHEAD OF SHORT WAVE AND ASSOCIATED SURFACE COLD FRONT WARMING TEMPERATURES TO AROUND 90F WITH EXCEPTION OF MOUNTAINS...AND ALONG THE MID COAST GIVEN ONSHORE TRAJECTORY. SCATTERED CONVECTION WILL DEVELOP TODAY ACROSS THE REGION WITH FORECAST SOUNDINGS INDICATING CAPES OF 1500 J/KG WITH POTENTIAL FOR A FEW STRONG STORMS WITH WINDS THE PRIMARY CONCERN. HAVE ADDED ENHANCED WORDING FOR STRONG GUSTY WIND AND SMALL HAIL TO PM CONVECTION. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... CONVECTION SHOULD QUICKLY END THIS EVENING WITH LOSS OF HEATING AND UPPER SUPPORT. SURFACE FRONT PRESSES SOUTH THEN STALLS AS HIGH PRESSURE BUILDS BY TO OUR NORTH OVERNIGHT INTO THE FIRST HALF OF SATURDAY. THICKER CLOUDS SPREAD NORTH AND EAST ON SATURDAY AS FRONT BEGINS RETURNING NORTH WITH AN INCREASING CHANCE FOR A SHOWER OR THUNDERSTORM AS WE HEAD THROUGH THE DAY. HIGHS SHOULD BE SEVERAL DEGREES COOLER THEN TODAY GIVEN CLOUDS AND AN ONSHORE FLOW. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A WARM AND VERY MOIST AIRMASS WILL BE TRANSPORTED NORTHWARD INTO NORTHERN NEW ENGLAND SATURDAY NIGHT THROUGH SUNDAY NIGHT AS THE AREA WILL BE SANDWICHED IN BETWEEN A LARGE HIGH PRESSURE SYSTEM OVER THE WESTERN ATLC AND AN APPROACHING COLD FRONT FROM THE WEST. THIS MAY MEAN A DECENT AMOUNT OF FOG/HAZE AND STRATUS SATURDAY NIGHT AND SUNDAY NIGHT. DEWPOINTS WILL PROBABLY REACH THE 70-75F RANGE SOMETIME SUNDAY AND SUNDAY NIGHT WHICH WILL MAKE IT VERY MUGGY. AS FAR AS POPS GO...LOOKS MAINLY DRY SATURDAY NIGHT AND SUNDAY ALTHOUGH A FEW THUNDERSTORMS MAY START IMPINGING ON THE AREA LATER SUNDAY AFTERNOON...ESPECIALLY IN NH. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS APPEARS TO BE SUNDAY NIGHT AND MONDAY MORNING WHEN THE SHORT WAVE AND COLD FRONTAL FORCING APPROACHES AND SUBSEQUENTLY MOVES ON THROUGH. THESE THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE VERY HEAVY RAINFALL RATES DUE TO THE VERY MOIST COLUMN. CAN/T RULE OUT A FEW STRONG STORMS AS WELL...ESPECIALLY IN TERMS OF WIND DESPITE BEST FORCING APPROACHING AT NIGHT. FRONT LOOKS TO MOVE OFFSHORE MONDAY WITH THE BEST CHANCE OF SHOWERS AND STORMS BEING IN THE MORNING. HOWEVER...WOULDN/T BE SURPRISED TO SEE THE FRONT ACTUALLY COME THROUGH SLOWER THAN CURRENTLY PROGGED...WHICH COULD MEAN HIGHER POPS MONDAY AFTERNOON AND LESSER POPS SUNDAY NIGHT. THEREAFTER...FAIR AND DRIER WEATHER IS EXPECTED INTO MIDWEEK. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH SATURDAY/...IFR/LIFR IN FOG...IMPROVING QUICKLY TO VFR THIS MORNING. SCATTERED AFTERNOON/EVENING MVFR IN SHOWERS AND THUNDERSTORMS. SCT IFR FRI NIGHT IN FOG FOLLOWED BY VFR SAT WITH WIDELY SCATTERED MVFR IN ANY PM SHOWERS OR THUNDERSTORMS. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...LOCAL IFR CONDITIONS POSSIBLE IN STRATUS AND FOG SATURDAY NIGHT THROUGH MONDAY MORNING AS VERY MOIST AIRMASS SITS ACROSS THE AREA. BEST CHANCE OF LOW CIGS AND VSBYS WILL BE AT NIGHT. SHOWERS AND STORMS A GOOD BET SUNDAY NIGHT AND MONDAY MORNING. THEREAFTER...CIGS AND VSBYS LOOK TO IMPROVE. && .MARINE... SHORT TERM /THROUGH SATURDAY...NO FLAGS EXPECTED. HOWEVER...LCL VSBY RESTRICTIONS IN FOG AND HAZE...WITH SCATTERED SHOWERS AND THUNDERSTORMS. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...COLD FRONT WILL APPROACH THE WATERS FROM THE WEST SUNDAY NIGHT AND CROSS MONDAY. AHEAD OF THE FRONT...A LONG SOUTHERLY FETCH OF WIND MAY BRING SEAS UP TO SCA LEVELS BY LATER SUNDAY AFTERNOON WHICH COULD LAST THROUGH MONDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ |
| #531478 (Received by flhurricane at: 9:29 AM 03.Aug.2012) AFDMLB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 925 AM EDT FRI AUG 3 2012 .DISCUSSION... .UPDATE...MORNING SOUNDINGS LOOKING MORE FAVORABLE FOR CONVECTIVE ACTIVITY LATER TODAY WITH 10Z CAPE SOUNDING SHOWING PWATS INCREASING TO 1.9 INCHES. 500 MB TEMPS HAVE COOLED TO -9 DEGS C AT THE CAPE AND MIAMI AND -8 AT TBW AND JAX. 300 MB UPR LOW OFF THE SC/GA COAST WILL SLIP SW OVER CENTRAL FL LATER TODAY WHICH SHOULD PROVIDE FURTHER COOLING ALOFT AIDING INSTABILITY. AT THE LOW LVLS...LOW LVL FLOW HAS TURNED MORE SOUTHERLY WITH MID LVL STEERING FLOW OUT OF THE SOUTH AT 5-10 KNOTS. TROPICAL WAVE AXIS WILL NOT MOVE ONSHORE UNTIL LATE TONIGHT INTO EARLY SATURDAY BUT INCREASED MOISTURE...INSTABILITY AND UPPER TROUGH ALOFT SHOULD PROVIDE MORE FAVORABLE CONVECTIVE ENVIRONMENT. HAVE INCREASED POPS OVER LOW MOS NUMBERS TO 30 PCT NORTH CSTL TO 40 PCT OVER THE INTERIOR. EXPECT A FEW STRONG STORMS BY LATE AFTN INTO THE EARLY EVENING WITH GUSTY WINDS TO 50 MPH AND SMALL HAIL POSSIBLE. && .AVIATION...EAST COAST SEA BREEZE WILL DEVELOP BY THE EARLY AFTERNOON AND MOVE INLAND INTO THE EVENING HOURS. SCT SHRA/TSRA WILL FORM ALONG AND AHEAD OF THIS BOUNDARY...PRODUCING TEMPO IFR/MVFR CONDS. BEST CHANCES FOR CONVECTION WILL BE OVER THE INTERIOR LATER IN THE AFTERNOON. WILL MAINTAIN VCTS IN TAFS FOR EXPECTED TIMING OF STORMS. ONSHORE MOVING SHOWERS AND STORMS WILL CONTINUE TO BE POSSIBLE... ESPECIALLY SOUTH OF KMLB AFT 04Z TONIGHT WITH APPROACH OF A TROPICAL WAVE. && TODAY-TONIGHT...SFC RIDGE AXIS WILL LIFT SLOWLY NORTHWARD OVER THE WATERS TODAY INTO TONIGHT AS A TROPICAL WAVE APPROACHES THE SE COAST OF FLORIDA. SOUTHERLY WINDS EARLY THIS MORNING WILL WEAKEN AND BECOME EAST/SOUTHEAST...REMAINING AROUND 5-10 KNOTS. WINDS WILL INCREASE UP TO 10-15 KNOTS TONIGHT AS WAVE APPROACHES THE COASTAL WATERS. SEAS TO REMAIN AROUND 2-3 FEET TODAY. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ |
| #531477 (Received by flhurricane at: 9:05 AM 03.Aug.2012) AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 853 AM EDT FRI AUG 3 2012 .UPDATE... CURRENT FORECAST LOOKS ON TRACK...SO NO SIGNIFICANT CHANGES PLANNED. WEAK TROUGHING...ALONG WITH MOIST/UNSTABLE CONDITIONS...WILL LEAD TO ANOTHER ROUND OF SCATTERED SHWRS/TSTMS THIS AFTERNOON. WITH THE COLD POOL NOT QUITE AS PRONOUNCED AS YESTERDAY AFTN...DO NOT EXPECT ORGANIZED SEVERE STORMS THIS AFTN. MOST OF THE ACTIVITY WILL FOCUS ALONG MESOSCALE BOUNDARIES SUCH AS THE GULF AND EAST COAST SEABREEZES AND ASSOCIATED OUTFLOWS...AND THESE BOUNDARIES WILL LIKELY COLLIDE LATE THIS AFTERNOON OR EARLY THIS EVENING OVER INTERIOR LOCATIONS. ANOTHER HOT AND HUMID AFTN IN STORE...WITH TEMPERATURES IN THE LOWER/MID 90S WITH MAXIMUM HEAT INDEX READINGS OF 100-107 DEGREES. && .AVIATION... VFR WILL GENERALLY PREVAIL FOR THE NEXT 24 HOURS. SCATTERED LATE AFTERNOON STORMS ARE EXPECTED AS THE SEA BREEZES MOVE INLAND. HAVE VCTS AT NE FL TERMINALS 20-24Z. && .MARINE... A RIDGE OF HIGH PRESSURE OVER THE REGION WILL LIFT TO THE NORTH OF THE WATERS THIS WEEKEND. S/SW WINDS THIS MORNING BECOMING SE ALONG THE COAST THIS AFTERNOON. WINDS WILL GENERALLY BE EAST TO SOUTHEAST OVER THE WEEKEND INTO NEXT WEEK WITH THE RIDGE NORTH OF THE AREA. NO HEADLINES EXPECTED. ISOLATED SHOWERS AND STORMS TODAY BECOMING SCATTERED OVER THE WEEKEND AND NEXT WEEK FROM A TROPICAL WAVE. RIP CURRENTS: LOW RISK THROUGH SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 95 74 93 72 / 40 20 40 20 SSI 89 78 87 77 / 20 20 40 20 JAX 95 75 92 74 / 30 30 40 20 SGJ 91 75 89 76 / 20 20 40 20 GNV 95 72 93 71 / 40 30 50 30 OCF 94 72 92 73 / 40 20 50 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ |
| #531476 (Received by flhurricane at: 9:03 AM 03.Aug.2012) AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 857 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE COAST TODAY....AND WILL REMAIN OFF THE COAST THIS WEEKEND. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION EARLY MONDAY. && .NEAR TERM /TODAY/... HIGH PRESSURE WILL SHIFT OFFSHORE DURING THE DAY. AN INCREASING SOUTHERLY FLOW WILL KEEP A MOIST AIR MASS IN PLACE TODAY. 850MB TEMPERATURES AND DEW POINTS REMAIN ABOUT THE SAME TODAY AS YESTERDAY...AND WITH LITTLE CHANGE IN THE ATMOSPHERE HIGH TEMPERATURES WILL AGAIN BE IN THE MID 90S. HEAT INDICES COULD EXCEED 100 DEGREES BETWEEN 2 PM AND 5 PM ESPECIALLY IN THE METRO AREAS BUT CONDITIONS SHOULD FALL SHORT OF A HEAT ADVISORY. SHOWERS AND THUNDERSTORMS WILL FIRE UP ALONG THE WESTERN MOUNTAINS BY EARLY AFTERNOON. AN ISOLATED STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE LATER IN THE AFTERNOON AS MOISTURE AND INSTABILITY IS RECIRCULATED. THE NAM KEEPS THE TROF OVER THE WVA PANHANDLE OVERNIGHT...CONTINUING THE RISK OF THUNDERSTORMS. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... THIS WKND CWFA WL BE BTWN HIPRES RDG IN THE WRN ATLC AND A CDFNT/H5 VORTMAX CROSSING THE GRTLKS. THE UPA PTTN FEATURES WLY FLOW MAINLY CONFINED TO THE NRN CONUS...W/ BROAD HIPRES ACRS THE SRN STATES. THAT/LL LEAD TO TYPICAL HEAT AND HUMIDITY...WHICH WL CULMINATE IN LT DAY TSRA. NO BIG CHGS TO TEMP FCSTS...PER MOS CONSISTENCY. SAT ACTIVITY WL FEED OFF OF TRRN CIRCULATIONS...THTE MAX...AND MESOSCALE BNDRYS-- THE LATTER OF WHICH WL BE DFCLT TO PIN DWN FM THIS STANDPOINT. HV BUMPED UP POPS AREAWIDE...AND ATTEMPTED TO ADD A LTL PLACEMENT/TIMING DETAIL NONETHELESS. USED CLIMO A BIT IN TIMING...ORIGINATING TSRA IN MTNS BY ELY AFTN...EVOLVING INTO LEE TROF ELY EVNG...AND THEN PUSHING TWD DELMARVA AFDK. SUN WL BE INFLUENCED MORE BY THE APPCHG BNDRY/UPR TROF...WORKING ON AN UNSTBL AMS. NAM/GFS/ECMWF SEEM TO HV DECENT HANDLE ON TIMING...W/ A SUN NGT CFP. DYNAMICS AND LAPSE RATES PREFERRED N OF CWFA...WHICH IS WHERE THE HIER POPS WERE PLACED. THAT/S NOT TO DISCOUNT STRENGTH OF ACTIVITY W/IN CWFA...AS THERE/S MORE THAN ADEQUATE INSTBY/SHEAR...SPCLY FOR NRN CNTYS. MENTION OF SVR IN HWO WUD APPEAR JUSTIFIED. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PATTERN WL BE DOMINATED BY AN UPPER LVL RDG OVR THE ROCKY MTNS AND SLT TROFFING IN THE ERN U.S. BECAUSE OF THIS THE REALLY HIGH HEAT IS XPCTD TO BE HELD AT BAY THRU THE 1ST WK OF AUG. AFTR THE FNT MOVES THRU...AND THERE`S NO GUARANTEE AT THIS TIME OF THE YR THAT IT WL...UPR TROF SHOULD BE A CONTROLLER. AS MENTIONED ABV TEMPS SHOULD NOT GO MUCH ABV THE CLIMO NORMS...BUT ALMOST ALL SUMMER MDL TEMP FCSTS HV NOT BEEN WARM ENUF. THE FLIP IS THERE WAS ONE TIME THIS SUMMER (THAT I CAN RECALL) WHERE AFTR A FNT WENT THRU WE MOVED INTO A CAD ENVIRONMENT AND TEMPS ACTUALLY WERE BLO NORMS. FOR TIME BEING WL KEEP HIGHS IN U80S/LOWS 65-70. && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... CUMULUS CLOUDS BASES FL050 POSSIBLE BY LATE AFTERNOON WITH LESS THAN A 20 PERCENT CHANCE OF A TS AT THE MAJOR TERMINALS THRU 22Z. SFC WINDS 18010KT. THIS CHANCE INCREASES TO 30 PERCENT BETWEEN 22Z AND 03Z...THEN DECREASES OVERNIGHT. FLGT RESTRICTIONS PSBL W/IN MAINLY DIURNAL TSRA SAT AND SUN. CVRG SUN MAY BE TIMED A LTL LATER DUE TO CFP. REDUCTIONS WUD BE BRIEF... POTENTIALLY DOWN TO IFR. ALSO MAY HV ELY MRNG VSBY RESTRICTIONS... MVFR MOST LKLY...THO IFR PSBL INVOF AREAS WHICH RECVD TSRA FM THE PRVS DAY. && .MARINE... SOUTHERLY CHANNELING COULD CAUSE SOME BREEZY AFTERNOON WINDS TODAY BUT EXPECTED TO REMAIN BELOW SCA CONDITIONS. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN THIS AFTERNOON. LOCALLY GUSTY WINDS AND LIGHTNING ARE POSSIBLE NEAR STORMS. SLY CHANNELING PSBL SAT EVNG...AND AGN LT SUN AHD OF CDFNT. POTL SCA FOR EACH OCCASION. ALSO WL HV TSRA DAILY TO CONTEND WITH...ANY OF WHICH MAY CONTAIN GUSTY WINDS. SMW/S PSBL. FROPA EITHER LT SUN OR ELY MON. && .TIDES/COASTAL FLOODING... WATER LEVELS ARE FORECAST TO RISE JUST ABOVE MINOR TIDAL FLOODING THRESHOLDS AT ALEXANDRIA AND THE SW WATERFRONT OF DC...AROUND THE ASTRONOMICAL HIGH TIDE LATER THIS MORNING. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR DCZ001. MD...NONE. VA...COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR VAZ054. WV...NONE. MARINE...NONE. && $$ UPDATE...WOODY! |
| #531475 (Received by flhurricane at: 8:35 AM 03.Aug.2012) AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 823 AM EDT Fri Aug 3 2012 .UPDATE...Aviation section for 12Z TAF cycle. && .NEAR TERM... [Today] A typical summer day is expected with scattered convection across the area. The PoP distribution was based on sea-breeze climatology, MOS guidance, and the hi-res guidance. The consensus ended up being around 50 percent across most of northwest Florida and southeast Alabama tapering to 40 percent across the northern zones. The severe storm threat appears slightly less than yesterday given a forecast of slightly lower instability and delta thetae values. However, values are still high enough that a pulse severe storm or two cannot be ruled out. Seasonably warm temperatures are expected. && .SHORT TERM... [Tonight through Sunday] Scattered diurnal convection will diminish tonight. On Saturday and Sunday, differences start to emerge between the NAM and the GFS. The NAM moves a weak tropical wave through the area on Saturday, and the GFS holds off until Sunday. Both models have an upper level shortwave dropping south and affecting the western zones on Saturday, so the likely PoPs from the previous forecast were maintained across that area. Elsewhere, scattered convection is expected on Saturday. PoPs were increased to likely on Sunday across northwest Florida in favor of the GFS with the expectation that a weak tropical wave will move westward through the area with increased moisture late in the day. This has some support from the 00z ECMWF as well. Seasonably warm temperatures are expected. && .LONG TERM... [Sunday night through next Friday] Weak tropical wave axis is forecast to pass across the forecast area late Sunday into Monday. With the southeasterly flow in the wake of the wave and a weakness aloft between subtropical ridges to the east and west, expect deep layer moisture to remain elevated on Monday with at least scattered showers and thunderstorms across the entire forecast area. The onshore low-level flow trajectory is expected to continue through at least Thursday, keeping PoPs elevated and temperatures near seasonal norms. && .AVIATION... [through 12Z Saturday] Fog has once again developed this morning across parts of Southwest and South Central GA. This fog has produced VLIFR conditions at ABY. IFR ceilings are being reported DHN with MVFR at ECP. The 12Z KTAE sounding shows that the surface inversion is very shallow this morning. Therefore, we expect the lowest conditions to improve rapidly, by around 13Z or possibly as late as 14Z. After VFR conditions establish themselves later this morning, a typical summertime pattern is expected for the rest of today, with scattered thunderstorms this afternoon and evening. Best chances for TSRA this afternoon appear to be at the FL terminals, where tempos are included in the forecast. && .MARINE... A ridge of high pressure south of the area is expected to keep light onshore winds through today. A tropical wave will then move west across the area late in the weekend swinging winds around to the east and southeast. A trough will establish itself north of the waters early next week with a ridge to the south. This will bring a return to light onshore winds. && .FIRE WEATHER... Afternoon Relative Humidity levels are expected to remain above critical thresholds for the next week, so red flag conditions are not expected. && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ |
| #531474 (Received by flhurricane at: 8:32 AM 03.Aug.2012) AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 726 AM CDT FRI AUG 3 2012 .DISCUSSION... FOR 12Z TAF ISSUANCE. && .AVIATION... ANOTHER DAY OF PERSISTENCE TERMINAL FORECASTS. UPPER RIDGE AXIS LINGERING OVER THE SRN PLAINS COULD ALLOW SOME CONVECTION TO DEVELOP PRIMARILY OVER THE ERN TERMINALS THIS AFTERNOON...BUT COVERAGE SHOULD REMAIN LOW SO REMOVED MENTION OF THUNDER FROM INHERITED KARA TAF. OTHERWISE SCATTERED CU SHOULD DEVELOP BY AFTERNOON BEFORE SEA BREEZE DEVELOPS AND SRLY WINDS PICK UP. 25 && .PREV DISCUSSION... /ISSUED 352 AM CDT FRI AUG 3 2012/ DISCUSSION... ONE MORE RELATIVELY QUIET WEATHER DAY...BEFORE RAIN CHANCE INCREASE FOR THIS WEEKEND. MID/UPPER LEVEL RIDGE IS EXPECTED TO SHIFT FURTHER WEST...ALLOWING SHORTWAVES ROTATING AROUND IT TO TRAVERSE OUR AREA...STARTING SATURDAY...AND CONTINUING TO AT LEAST MONDAY. BEYOND THAT...GOING WITH MORE TYPICAL LATE MORNING/AFTERNOON SHOWERS AND THUNDERSTORMS ASSOCIATED WITH SEA BREEZE. TEMPERATURE FORECASTS MAY BE MORE TRICKY DUE TO LOCATION AND TIMING OF SHOWERS AND THUNDERSTORMS THAT CAN CHANGE A MID 90S HIGH TO AN UPPER 80S READING...SO THERE IS SOME UNCERTAINTY IN THE MAX TEMPS THIS WEEK...BUT GOING WITH A NEAR NORMAL TO A DEGREE OR TWO ABOVE NORMAL. LOW TEMPS ALSO CAN BE INFLUENCED BY THE CONVECTION...BUT CLIMO LOWS IN THE MID AND UPPER 70S APPEAR REASONABLE. OF COURSE...ALSO MONITORING THE PROGRESS OF TROPICAL STORM ERNESTO...WHICH BEARS WATCHING FOR POSSIBLE GULF OF MEXICO ENTRANCE BY THE MIDDLE OF NEXT WEEK...IF IT CAN HOLD TOGETHER WITH AS MUCH SHEAR/DRY AIR IN ITS ENVIRONMENT TODAY. && .PRELIMINARY POINT TEMPS/POPS... KLCH 93 79 93 77 93 / 10 10 20 20 30 KBPT 93 78 93 77 93 / 10 10 20 20 30 KAEX 96 75 96 75 95 / 20 10 20 20 50 KLFT 94 78 91 76 91 / 20 10 30 20 50 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ |
| #531472 (Received by flhurricane at: 7:54 AM 03.Aug.2012) AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 649 AM CDT FRI AUG 3 2012 .DISCUSSION...UPDATED FOR 12Z AVIATION. && .AVIATION...EXPECT SIMILAR CONDITIONS TO THE PAST 24 HOURS WITH LIGHT WINDS THIS MORNING BECOMING GUSTY IN THE AFTERNOON. SKIES SHOULD REMAIN FEW TO SCT THROUGH THE DAY. AN INCREASED LOW LEVEL JET COULD KEEP GUSTY WINDS AT LRD INTO THE NIGHT. OTHERWISE EXPECT WINDS TO DECREASE OVERNIGHT WITH FEW TO SCT STRATO CU ONCE AGAIN. && .PREV DISCUSSION... /ISSUED 402 AM CDT FRI AUG 3 2012/ SHORT TERM (TODAY THROUGH SATURDAY)...HIGH PRESSURE RIDGE SHIFTING TO THE WEST AND A BIT NORTH OVER THE NEXT 24-36 HOURS. THIS WILL ALLOW MOISTURE TO GRADUALLY INCREASE ACROSS THE AREA. EXPECT TODAY TO REMAIN NEARLY IDENTICAL TO CONDITIONS EXPERIENCED YESTERDAY. WENT WITH A PERSISTENCE MAX T FORECAST FROM YESTERDAY MAX T OBSERVATION...WITH JUST A FEW TWEAKS. ONLY OTHER DEVIATION FROM YESTERDAY IS THE POSSIBILITY FOR A FEW MORE CLOUDS THIS AFTERNOON WITH THE INCREASING MOISTURE. BY LATE TONIGHT PWAT VALUES ARE APPROACHING 1.5 INCH AND INCREASING FURTHER INTO SATURDAY. HAVE NOT CHANGED PRECIP FORECAST MUCH FROM PREVIOUS PACKAGE...WITH SLIGHT CHANCE POPS FOR MARINE AREAS LATE TOMORROW NIGHT...AND FOR MARINE PLUS COASTAL BEND FOR SATURDAY. LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...MOISTURE PROFILES IMPROVE SOME ON SUNDAY AND MONDAY...WITH PWATS AOA 2 INCHES OVER THE NORTHEAST SUNDAY AND COASTAL AREAS MONDAY. ISSUE HOWEVER IS HOW MUCH DOMINANCE UPPER HIGH WILL HAVE...AS GFS IS NOT MOVING UPPER HIGH AS FAR WEST AS PREVIOUSLY MODEL RUNS HAVE SHOWN. STILL...CAP BECOMES WEAKER WITH 700MB TEMPS AOB 10C BY MONDAY NEAR THE COAST. AS A RESULT...WILL NOT ONLY CONTINUE WITH LOW-END POPS BUT WILL INCREASE THEM FOR SUNDAY AND MONDAY OVER THE NORTHEAST TO LOW CHANCE (WOULD GO EVEN HIGHER IF RIDGE WAS NOT AS STRONG AS SHOWN. MOISTURE LINGERS ENOUGH FOR TUESDAY TO INCLUDE POPS AS HAVE HAD BEFORE. BIT DRIER AIR FOR WEDNESDAY AND MODELS DIFFER ON UPPER LOW/TUTT...WITH ECMWF HAVING THIS FEATURE WELL SOUTH IN MEXICO AND INLAND BY WEDNESDAY EVENING WHILE GFS BLOCKING SYSTEM WITH HIGH THEN MOVING IT INLAND BY THURSDAY (AND THAT COULD IMPACT DIRECTION OF ERNESTO IF THAT PANS OUT). FOR NOW...WILL KEEP THE LOW CHANCE POPS OVER THE EASTERN AREAS GIVEN POTENTIAL FOR TUTT BUT CONFIDENCE IN ISOLATED CONVECTION IS NOT AS GOOD AS YESTERDAY. OTHERWISE...DAYTIME TEMPERATURES CONTINUE TO REMAIN SLIGHTLY ABOVE NORMAL...WITH NEAR TO SLIGHT ABOVE NORMAL LOWS (MORE CLOSER TO NORMAL WHEN WINDS ARE LIGHT OR SOUTH-SOUTHWEST TOWARD MORNING. UNCERTAINTY DEFINITELY INCREASES AFTER THURSDAY AS ALL WILL DEPEND ON ERNESTO...WHERE IT IS AND HOW STRONG IT IS...AS WELL AS THE UPPER PATTERN WHICH WILL DICTATE WHERE ERNESTO WILL GO (IF IT GOES TOO FAR SOUTH AND INTO MOUNTAINS AS SOMETHING WEAKER MAY NOT BE MUCH OF AN ERNESTO...THAT IS WHAT ECMWF IS SAYING). HOWEVER...THAT IS BEYOND THIS FORECAST PERIOD BUT POTENTIAL CHALLENGING FORECAST ON THE HORIZON. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 97 79 96 79 97 / 10 10 20 10 20 VICTORIA 95 76 95 76 96 / 0 0 20 10 30 LAREDO 105 79 103 80 102 / 0 0 10 10 10 ALICE 102 77 100 77 100 / 0 0 10 10 20 ROCKPORT 90 80 93 81 93 / 10 10 20 10 30 COTULLA 106 75 102 76 103 / 0 0 10 10 10 KINGSVILLE 99 78 99 78 99 / 0 0 10 10 20 NAVY CORPUS 91 80 93 81 92 / 10 10 20 10 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531471 (Received by flhurricane at: 7:50 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 741 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM THURSDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA WITH POSSIBLE THUNDER...OVER INLAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE CONTINUED DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND THE MID LEVEL DYNAMICS FROM THE VORT...WILL ALL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 12Z...VFR EXPECTED THROUGH VALID PERIOD...WITH EXCEPTION OF POTENTIAL FOG OVERNIGHT INTO SATURDAY. LIGHT AND VARIABLE WINDS THIS MORNING CONTINUE WITH A FEW ISOLATED SHOWERS IN AND AROUND THE AREA AS WELL AS PATCHY FOG. CANNOT RULE OUT CONTINUED ISOLATED -SHRA THIS MORNING BUT DO NOT ANTICIPATE ANY LONG LIVED RESTRICTIONS TO ARISE FROM THIS ACTIVITY. AS VFR PREVAILS...SOUTH-SOUTHEAST WINDS WILL INCREASE TO AOB 10 KTS THROUGHOUT THE DAY WITH MID TO HIGH LEVEL CLOUDS. HAVE INTRODUCED VCTS/VCSH FOR THIS AFTERNOON AND EVENING. CONVECTION WILL BE ISOLATED TO SCATTERED IN NATURE ACROSS THE ENTIRE AREA. CANNOT RULE OUT BRIEF RESTRICTIONS...THOUGH CONFIDENCE IS LOW. INTO THE OVERNIGHT HOURS...VFR WILL PREVAIL WITH WITH WINDS BECOMING LIGHT. POSSIBILITY OF FOG DEVELOPMENT CANNOT BE RULE OUT OVERNIGHT...ESPECIALLY AT THE INLAND SITES. COULD CREATE MVFR/BRIEF IFR/CONDITIONS. AFTER DAYBREAK...FOG WILL DISSIPATE ALLOWING VFR TO PREVAIL WITH SOUTHWEST WINDS AOB 8 KTS. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WIND DIRECTIONS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531469 (Received by flhurricane at: 7:30 AM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 726 AM EDT FRI AUG 3 2012 .SYNOPSIS... VERY WARM AND HUMID WEATHER WILL PERSIST THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND THUNDERSTORMS...BUT SHOWERS AND THUNDERSTORMS ARE MORE LIKELY MONDAY WHEN A COLD FRONT CROSSES SOUTHERN NEW ENGLAND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST BY THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... LOW STRATUS AND FOG SHOULD DISSIPATE OVER THE NEXT COUPLE OF HRS ACROSS THE CAPE AND ISLANDS WITH SUNRISE AND SUBSEQUENT MIXING OF THE BOUNDARY LYR. THEREAFTER...FOCUS SHIFTS TO ANTICIPATED AFTERNOON SHOWERS AND THUNDERSTORMS. PREVIOUS DISCUSSION APPLIES. PREVIOUS DISCUSSION... MAIN CONCERN TODAY DEALS WITH POTENTIAL FOR SHOWERS AND THUNDERSTORMS. 00Z MODELS SHOW PLENTY OF INSTABILITY WITH SURFACE BASED CAPES 1500-2500 J/KG AND MARGINAL MID LEVEL LAPSE RATES NEAR 6C/KM. HOWEVER WINDS ALOFT REMAIN RATHER WEAK WHICH LEADS TO POOR 0-6KM SHEAR. APPROACHING COLD FRONT IS EXPECTED TO WEAKEN AS IT REACHES SOUTHERN NEW ENGLAND THIS AFTERNOON...BUT SHOULD BECOME FOCUS FOR SCATTERED SHOWERS/STORMS TO DEVELOP. MAIN THREAT WILL BE LOCALLY HEAVY RAIN...BUT PER SPC DAY 1 OUTLOOK THERE IS ALSO A LOW PROBABILITY OF STRONG WIND GUSTS AND HAIL IF HIGHER CORES CAN MANAGE TO DEVELOP. PROBABLY LOOKING AT PULSE STORMS WHICH MAY ATTEMPT TO FORM INTO BOWING SEGMENTS. EXPECT INITIAL ACTIVITY TO REACH SW NH AND NW MA LATER THIS MORNING /HRRR LOOKS REASONABLE WITH 14Z-15Z ONSET/...BUT EXPECT MOST OF STORMS WILL OCCUR BETWEEN NOON AND 5 PM ALONG MASS PIKE CORRIDOR AND INTO HARTFORD AND PROVIDENCE. NOT CONFIDENT STORMS WILL FIRE CLOSER TO S COAST GIVEN STABILIZING SW FLOW...BUT WITH FAIRLY HIGH CAPE STORMS CANNOT BE RULED OUT DOWN THERE EITHER. 850 MB TEMPERATURES ARE PROGGED TO REACH 17-18C WHICH WOULD YIELD HIGHS IN 90S WITH FULL SUN. NAM MOS HAS LOW TO MID 90S ACROSS MUCH OF AREA WHICH LOOKS A LITTLE HIGH GIVEN SOME EXPECTED CLOUD COVER... SO LEANED MORE TOWARD GFS MOS TODAY WITH MID 80S TO MID 90S. DEWPOINTS NEAR 70 /ESPECIALLY S OF MASS PIKE/ YIELDS HEAT INDICES IN MID TO UPPER 90S WHICH IS BELOW HEAT ADVISORY CRITERIA. && .SHORT TERM /SATURDAY/... ISOLATED SHOWERS/STORMS WILL BE SLOW TO DIMINISH THIS EVENING DESPITE LOSS OF DAYTIME HEATING DUE TO PLENTY OF LOW LEVEL MOISTURE AND WEAK CONVERGENCE ALONG DISSIPATING FRONT. SHOULD SEE ANOTHER NIGHT OF LOW CLOUDS AND PATCHY FOG...MAINLY NEAR S COAST. USED A BLEND OF GFS/NAM MOS WHICH ARE CLOSE TO EACH OTHER. COLD FRONT WILL HAVE WASHED OUT OVER SOUTHERN NEW ENGLAND SAT...BUT SHOULD STILL BECOME A FOCUS FOR SCATTERED SHOWERS AND STORMS ONCE AGAIN. MODELS INDICATE THIS MAY BEGIN A BIT EARLIER THAN TODAY...BY MID TO LATE MORNING...AS SOME WEAKENING UPSTREAM CONVECTION COMES INTO PLAY. LOOKS LIKE ANOTHER DAY WITH POTENTIALLY HIGH CAPE AND WEAK SHEAR BUT WITH BETTER MID LEVEL LAPSE RATES...SO POTENTIAL FOR GUSTY WINDS AND HAIL MAY BE A LITTLE HIGHER THAN TODAY. LEANED CLOSER TO GFS MOS FOR HIGHS GIVEN EXPECTED CLOUD COVER AND A POSSIBLE EARLIER START TO CONVECTION...IN 80S TO AROUND 90. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... * QUIET AND MILD SAT NGT * RAIN BECOMING WIDESPREAD SUN-MON ALONG AND AHEAD OF A COLD FRNT * HEAVY RAIN EXPECTED...FLOODING IS A DISTINCT POSSIBILITY * ENERGY OFFSHORE AROUND TUE MORN...QUIET WX EXPECTED INTO WED * ANOTHER DISTURBANCE PSBL INTO THE END OF THE WEEK MODEL DIAGNOSIS... MDL SOLNS ARE STILL TRENDING WITH A PERSISTENT GENERAL PATTERN OF A DEEP POLAR VORTEX ACROSS THE NRN HUDSON BAY RGN WITH A SERIES OF DISTURBANCES ROTATING AROUND THE PERIMETER AND ACROSS THE NERN CONUS. MEANWHILE STRONG RIDGING PERSISTS THRU THE ATLANTIC AND WRN ROCKIES. THE MID-HIGH LATITUDE BLOCKING PATTERN KEEPS AN ACTIVE PATTERN FOR THE FCST. BUT WATCHING A PSBL EWD SHIFT IN THE PATTERN OVER THE NWRN CONUS BY THE FOLLOWING WEEK AS A SERIES OF DISTURBANCES PROMOTE DEEP TROUGHING THRU THE GULF OF ALASKA...CONSEQUENTIALLY SHIFTING THE MAIN RIDGE OF HIGH PRES ACROSS THE CENTRAL CONUS TOWARDS THE ERN CONUS. OVERALL...WHILE MDL SOLN CONTINUITY HAS PERSISTED INTO THE BEGINNING OF NEXT WEEK WITH THE 02/12Z GUIDANCE...THEREAFTER IT HAS REMAINED UNCERTAIN DUE TO RUN TO RUN VARIABILITY OF TIMING/PHASING OF KEY FEATURES ACROSS THE MID-HIGH LATITUDES. HPC HAS EMPHASIZED A MORE CONSENSUS APPROACH WITH EQUAL WEIGHTING OF DETERMINISTIC AND ENSEMBLE MDL SOLNS. OF GREATER CERTAINTY...MDL SOLNS IN BETTER AGREEMENT OF ACTIVITY INITIATING SUNDAY AND CONTINUING SUNDAY NIGHT INTO MONDAY WITH THE APPROACH OF A SFC COLD FRNT. AM STILL CONCERNED OVER THE PROLONGED PERIOD OF SUB-TROPICAL MOISTURE FETCH NEWD ACROSS NEW ENGLAND AHEAD OF THE COLD FRNT /PWATS AROUND 2.25 IN/ WARRANTING THE POSSIBILITY OF FLOOD WATCHES. BETTER AGREEMENT OF THE COLD FRNT AND ATTENDANT ENERGY OFFSHORE BY TUE MORN. AND FINALLY...THERE IS ALSO SLIGHTLY BETTER CONSENSUS OF A FOLLOW UP DISTURBANCE BY THE END OF THE WEEK. SATURDAY NIGHT... CONVECTIVE ELEMENTS DURING THE DAY DIMINISH AS WEAK HIGH PRES TAKES CONTROL. SLY FLOW ENHANCING THRU THE EVNG IN RESPONSE TO THE APPROACHING SYNOPTIC SYS ACROSS THE GRT LKS BY SUNDAY MORN. WILL SEE A SURGE OF LOW 70 DEWPOINTS TOWARDS THE S SHORE OF NEW ENGLAND. CANT RULE OUT THE DEVELOPMENT OF LOW STRATUS AND FOG FOR SHORELINE COMMUNITIES. SHOULD BE A MILD NIGHT WITH MINS RANGING FROM THE UPR 60S TO LOW 70S /MID 70S PSBL/. SUNDAY THROUGH MONDAY... THE COMBINATION OF ENHANCED LOW-MID LVL FLOW OF SUB-TROPICAL AIR FROM THE SERN CONUS ON SUNDAY CONVERGENT ALONG A PSBL PRE-FRONTAL TROUGH...AND DESTABILIZATION OF THE LOCAL BOUNDARY LYR...WARRANTS CHC POPS FOR SUNDAY INTO SUNDAY NGT. ADVERTISED PWATS DURING THIS TIMEFRAME ARE AROUND 2 INCHES WITH MDL SOUNDINGS INDICATED A FAIRLY MOIST ADIABATIC PROFILE WITH THIN ELONGATED CAPE THRU THE ATMOS COLUMN OF 500-1000 J/KG. PRESENT THINKING IS FOR SHOWERS AND THUNDERSTORMS TO INCREASE IN AERIAL COVERAGE THRU THE DAY ACROSS THE MID-ATLANTIC NEWD INTO NEW ENGLAND. BEST POP CHCS WILL BE OVER WRN AND CENTRAL NEW ENGLAND. WHILE STORMS /LIKELY PULSY IN NATURE/ ARE EXPECTED TO BE SUB-SEVERE...HEAVY RAIN WILL BE A THREAT. ACTIVITY SHOULD CONTINUE SUNDAY NIGHT INTO MONDAY ALONG AND AHEAD OF THE COLD FRNT FCST TO SLIDE THRU THE RGN AND OFFSHORE BY TUE MORN. FRONTOGENETICAL FORCING OF CONTINUED LOW-MID LVL SWLY ADVECTION OF SUB-TROPICAL AIR SHOULD LEND TO LIKELY POPS FOR SHOWERS AND THUNDERSTORMS. SOME UNCERTAINTY AS TO WHETHER CLOUDS WILL BREAK ALLOWING FOR DESTABILIZATION OF THE BOUNDARY LYR ON MONDAY. NEVERTHELESS THE POSSIBILITY FOR ELEVATED CONVECTION EXISTS WITH CAPE VALUES HOVERING AROUND 500-1000 J/KG WITHIN A VERY MOIST ADIABATIC ENVIRONMENT. EXPECTED EMBEDDED HEAVIER RAINS WITH PULSE TYPE CONVECTION. PWATS ADVERTISED AROUND 2.25 INCHES AHEAD OF THE COLD FRNT WARRANT THE POSSIBILITY OF FLOODING. TUESDAY AND TUESDAY NIGHT... LOOKS TO REMAIN DRY WITH WEAK HIGH PRES ACROSS THE RGN IN WAKE OF MONDAYS DISTURBANCE SITTING OFFSHORE OF NEW ENGLAND. SLIGHTLY COOLER AND DRIER AIR BUILDS INTO THE RGN /H85 TEMPS AROUND +14C/. LGT AND VRB W/SWLY FLOW. WEDNESDAY THROUGH FRIDAY... A SECOND DISTURBANCE WITH ATTENDANT COLD FRNT IS EXPECTED TO SLIDE THRU THE RGN...USURPING ONCE AGAIN BETTER SUB-TROPICAL MOISTURE FROM THE SERN CONUS. MDL SOLNS VARY WITH OUTCOMES BASED ON EVOLUTION OF MID-LYR FEATURES THRU THE MID-HIGH LATITUDES. AM SOMEWHAT HESITANT TO ACCEPT THE 03/0Z GFS SOLN...RATHER AM MORE FAVORABLE TO THE SIMILAR TRENDS PER 03/0Z CANADIAN AND 02/12Z ECMWF. WILL HINT AT PRECIP FOR WED-THURS...WITH IMPROVEMENT FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND WITH ACTIVITY SHUNTED OFFSHORE BY HIGH PRES BUILDING S OUT OF CANADA. && .AVIATION /11Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT OVERVIEW...MODERATE CONFIDENCE. LOW STRATUS AND FOG SHOULD DISSIPATE THE NEXT HR OR TWO. THEREAFTER FOCUS PERTAINS TO AFTN SHRA/TSRA WHICH WILL BE SCTD AROUND 18-20Z THRU CENTRAL NEW ENGLAND...SLIDING SEWD TOWARDS SERN NEW ENGLAND TOWARDS 22-0Z. ANY IMPACTS TO TERMINALS MAY RESULT IN +SHRA/+TSRA WITH MVFR-IFR VSBYS. STORMS SHOULD DISSIPATE WITH SUNDOWN. WITH SLY FLOW CONTINUING... PERSISTENCE SHOULD DOMINATE AS WE HAVE SEEN THE PAST COUPLE OF EVNGS OF LOW STRATUS AND FOG DEVELOPING ACROSS THE S/SE COASTLINE OF NEW ENGLAND...BUILDING INTO THE INTERIOR. EXPECT LOCALES ACROSS THE S COAST TO FALTER TO VSBYS AROUND 1SM AND CIGS BELOW 500 FT AGL. INTO SATURDAY...LOW CIGS AND FOG DISSIPATE DURING THE MORNING HRS FOLLOWED BY MIDDAY-AFTN CONVECTION. KBOS TAF...MODERATE CONFIDENCE. PREVAILING VFR WITH SCTD AFTN CONVECTION PSBL. AM NOT CONFIDENT OF ANY VSBY AND/OR LOW CIG IMPACTS FOR TONIGHT INTO SAT. KBDL TAF...MODERATE CONFIDENCE. VSBYS IMPROVING WITH SUNRISE...THEREAFTER CONVECTION PSBL INTO THE AFTN HRS...DISSIPATING BY SUNDOWN. EXPECTING SOME MVFR VSBY IMPACTS CLOSER TO THE MORNING HRS SATURDAY. OUTLOOK...SUNDAY THROUGH TUESDAY... SATURDAY NIGHT...MODERATE TO HIGH CONFIDENCE. EXPECTING FOG AND LOW STRATUS /IFR-LIFR IMPACTS/ ALONG THE S COAST ADVECTED NWD BY INCREASING SLY FLOW. THRU THE INTERIOR...MID-UPR LVL CLOUDS ON THE INCREASE...PREVAILING VFR. SUNDAY THROUGH MONDAY...MODERATE CONFIDENCE. INCREASING AERIAL EXTENT OF SHRA/TSRA ALONG AND AHEAD OF AN APPROACHING COLD FRNT FROM THE W. SHRA/TSRA MAY BE HEAVY AT TIMES... ESPECIALLY MONDAY AS THE COLD FRNT TRAVERSES THE TERMINALS... PUSHING OFFSHORE BY TUE MORN. PREVAILING MVFR-VFR...TEMPO IFR VSBY IMPACTS WITH +SHRA/+TSRA. ESPECIALLY DURING EVNG PDS...EXPECTING FOG AND LOW STRATUS ALONG THE S COAST WITH IFR-LIFR IMPACTS. STRONG SLY FLOW WITH GUSTS UP TO 25 KTS THRU THE ENTIRE PD. TUESDAY...MODERATE CONFIDENCE. WLY WIND FLOW. PREVAIL VFR. LESSER CHCS FOR FOG AND LOW STRATUS. && .MARINE... FAIRLY CONFIDENT WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH SAT. SW WINDS GUST TO 20KT ALONG S COAST THIS AFTERNOON...WHICH INCLUDES BUZZARDS BAY AND VINEYARD SOUND...BUT PROBABILITY OF REACHING 25KT IS LOW. SEAS WILL CONTINUE TO BUILD SLOWLY ON S COASTAL WATERS DUE TO PERSISTENT SW FLOW BUT ARE NOT EXPECTED TO REACH 5 FT. MAIN HAZARDS INCLUDE SCATTERED TSTMS THIS AFTERNOON AND SAT AFTERNOON...MAINLY FROM NARRAGANSETT BAY TO BOSTON HARBOR AND MERRIMACK RIVER...AND PATCHY DENSE FOG ON S COASTAL WATERS LATE TONIGHT AND SAT MORNING. OUTLOOK...SUNDAY THROUGH TUESDAY... INCREASING SLY FLOW ALONG AND AHEAD OF AN APPROACHING COLD FRNT WILL RESULT IN SWELL AND HIGH SEAS ACROSS THE S WATERS /WAVE HEIGHTS OF AROUND 7 FT FOR THE OUTER WATERS...WITH 5-7 FT FOR THE INNER WATERS ALONG THE S COAST/. E WATERS WILL GRADUALLY RISE AS WELL. GUSTS UP TO 25 KTS CAN BE EXPECTED BEGINNING LATE SUNDAY THROUGH TUE BY WHICH POINT THE COLD FRNT WILL HAVE SHUNTED E...TRANSITIONING OUT TO SEA. AERIAL EXTENT OF SHOWERS AND THUNDERSTORMS WILL INCREASE THRU THE PD...BEGINNING SUNDAY. SOME OF THESE STORMS...ESPECIALLY ALONG AND AHEAD OF THE COLD FRNT...WILL BE ASSOC WITH HEAVY RAIN AND REDUCED VSBYS. RAINS AND ACTIVITY SHOULD BE E OF THE WATERS BY LATE MORN INTO MIDDAY TUE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR MAZ004>006-009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ |
| #531468 (Received by flhurricane at: 7:29 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 723 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHENS OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MINOR ADJUSTMENTS MADE TO CURRENT CONDITIONS...OTHERWISE FORECAST REMAINS ON TRACK. WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /11Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR THROUGH THE TAF PERIOD. THE ONLY EXCEPTION WILL BE SOME MVFR OR IFR FOG. ANY SUB-VFR CIGS ARE EXPECTED TO IMPROVE TO VFR BY 1300Z-1330Z. WINDS ARE GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IN THE TAFS. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. GENERALLY LOOKING AT ANOTHER VFR NIGHT...HOWEVER ANOTHER NIGHT OF PATCHY FOG MAY LOWER VSBYS DOWN TO MVFR OR IFR CONDITIONS...MAINLY LATE IN THE TAF PERIOD. WILL LEAVE ANY FOG OUT OF THE TAFS FOR NOW WITH LOW CONFIDENCE OF TIMING AND PLACEMENT OF FOG TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS MORNING OR EARLY THIS AFTERNOON FOR TIMING OF SEABREEZE. OUTLOOK FOR 12Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...NV/DW |
| #531467 (Received by flhurricane at: 7:27 AM 03.Aug.2012) AFDBRO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 618 AM CDT FRI AUG 3 2012 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...VFR CONDITIONS TO PREVAIL THE NEXT 24 HOURS AS HIGH PRESSURE AT THE SURFACE AND ALOFT MAINTAIN SUBSIDENCE ACROSS ALL OF SOUTH TEXAS. MAIN CUMULUS FIELD TO EXTEND ALONG AND EAST OF HIGHWAY 281. A LOCAL PRESSURE GRADIENT WILL ALLOW FOR THE SOUTHEAST WINDS TO BECOME GUSTY DURING THE AFTERNOON WITH SOME GUSTY PERIODS OF 20 TO 25 KNOTS BETWEEN 18Z TODAY AND 03Z SATURDAY. && .PREV DISCUSSION... /ISSUED 518 AM CDT FRI AUG 3 2012/ DISCUSSION...AN ERROR OCCURED DURING SOME PROCEDURE CHECK OF THE GRIDS BEFORE ISSUANCE OF EARLIER FORECAST PACKAGE. HIGH TEMPERATURES ON SATURDAY WHERE SOMEHOW LOWERED BY 2 TO 5 DEGREES OVER WHAT THEY SHOULD DEPICT. A CORRECTED VERSION IS OUT AND THE TEMP/POP TABLE BELOW HAS BEEN UPDATED. WE APOLOGIZE FOR ANY FOR ANY INCONVENIENCE THAT THIS MAY HAVE OCCURRED. PREV DISCUSSION... /ISSUED 345 AM CDT FRI AUG 3 2012/ SHORT TERM /TODAY THROUGH SATURDAY/...LATEST MODEL PACKAGE SHOWS LITTLE CHANGE IN UPPER RIDGE STRUCTURE OVER THE NEXT 36 HOURS. THE CENTER OF THE DEEP LAYERED RIDGE TO REMAIN OVER NORTH CENTRAL TO NORTHWEST TEXAS MAINTAINING STRONG SUBSIDENCE AIR ACROSS SOUTH TEXAS. PLENTY OF HEAT AND DRY AIR TO REMAIN IN PLACE TODAY AND SATURDAY WITH LITTLE TO NO RAIN EXPECTED. ANY ADDED MOISTURE ON SATURDAY IS NOT LIKELY TO KICK OFF ANYTHING MORE THEN ONE OR TWO SHOWERS OR THUNDERSTORMS. WARM AIR ALOFT TO MAINTAIN A CAP. INVERTED TROUGH THAT HAS BEEN TALKED ABOUT HAS BECOME STRETCHED OUT AND WEAKER AND STRONGER THEN USUAL SOUTH WINDS ARE NOT CONDUCIVE FOR AN ACTIVE SEA BREEZE. WITH THIS SAID...LOWERED SATURDAY POPS BELOW 20 PERCENT WITH KENEDY COUNTY THE BEST AREA TO SEE ISOLATED CONVECTION. TEMPERATURES TO REMAIN WELL ABOVE NORMAL WITH GOING FORECAST REMAINING ABOVE ALL GUIDANCE VALUES. SOUTHEAST WINDS TO INCREASE FRIDAY AND SATURDAY AFTERNOON WITH INLAND AREAS SEEING GUSTS BETWEEN 25 TO 30 MPH. LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...PATTERN SHIFT NEXT WEEK STILL EXPECTED TO BRING SOME CHANGES TO THE STAGNANT DOLDRUMS THAT HAVE BEEN THE PAST WEEK. THE UPPER RIDGE WILL SHIFT WESTWARD TO THE FOUR CORNERS REGION STARTING SUNDAY...TAKING THE CORE OF THE SUBSIDENCE WITH IT. AN INVERTED TROUGH WILL SHARPEN ACROSS THE SOUTHEASTERN US AND CHASE THE RIDGE WESTWARD ACROSS THE NORTHERN GULF. THIS WILL INTRODUCE DEEPER MOISTURE. THIS MOISTURE AND INSTABILITY FROM THE TROUGH WILL ALLOW THE SEABREEZE TO ACTIVATE EACH DAY AND PERSIST THROUGH THE WEEK. TEMPERATURES WILL REMAIN ABOVE NORMAL...BUT WILL BE HELD DOWN SLIGHTLY DUE TO DEEPER MOISTURE IN THE REGION. AS THE RIDGE MOVES WEST...THE HEAT LOW THAT HAS PERSISTED IN NORTH TEXAS WILL ALSO DEPART...ALLOWING WINDS TO SLACKEN FOR MOST OF THE WEEK. MARINE...NOW THROUGH SATURDAY...LOCAL PRESSURE GRADIENT WILL CONTINUE TO PRODUCE SMALL CRAFT EXERCISE CAUTION WINDS MAINLY OVER THE OPEN GULF DURING THE OVERNIGHT HOURS AND ACROSS THE LAGUNA DURING THE LATE MORNING AND AFTERNOON HOURS. A FEW AREAS NEAR PORT MANSFIELD COULD SEE INTERMITTENT SMALL CRAFT ADVISORY CONDITIONS BUT DURATION IS NOT LIKELY TO BE LONG ENOUGH TO WARRANT AN ADVISORY AT THIS TIME. SEAS CONSIST OF MAINLY WIND WAVES WHICH WILL FLUCTUATE 1 TO 3 FEET DURING THE DAY AND 3 TO 5 FEET OVERNIGHT. SATURDAY NIGHT THROUGH WEDNESDAY...LOW PRESSURE THAT HAS BEEN MEANDERING ACROSS NORTH TEXAS WILL WEAKEN AND SHIFT FURTHER WEST FOR THE EXTENDED PERIOD...ALLOWING WINDS TO SLACKEN TO AROUND 10 KNOTS. THIS WILL BRING LIGHTER SEAS 3 FEET OR LESS FOR THE FORECAST PERIOD. SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE EACH DAY DUE TO INSTABILITY ALOFT AND DEEPER MOISTURE. FIRE WEATHER...ENHANCED FIRE DANGER CONDITIONS WILL BE POSSIBLE MAINLY FROM 281 WESTWARD TODAY AND SATURDAY AFTERNOON. DRY AIR LOFT TO MIX DOWN TO THE SURFACE WITH DEW POINTS AND RELATIVE HUMIDITY VALUES TO FALL RAPIDLY THROUGH THE AFTERNOON. RH VALUES TO DROP BETWEEN 20 AND 30 PERCENT AND POSSIBLY BELOW 20 PERCENT IN ZAPATA, STARR AND JIM HOGG COUNTIES. 20FT WINDS ARE EXPECTED TO BE BELOW CRITICAL FIRE DANGER LEVELS...BUT CRITICAL GROWTH CONDITIONS ARE WARRANTED AS GUSTS RANGE FROM 20 TO 25 MPH LATE IN THE AFTERNOON AND VEGETATION REMAINS VERY DRY. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531466 (Received by flhurricane at: 7:26 AM 03.Aug.2012) AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 724 AM EDT FRI AUG 3 2012 .AVIATION...VFR WILL PREVAIL UNTIL SCATTERED TSRA DEVELOPS THIS AFTERNOON. SO HAVE VCTS ALL SITES. MORNING SHOWERS COULD MOVE ONSHORE THE ATLANTIC COAST THIS MORNING. MVFR OR IFR IS POSSIBLE WITH THE AFTERNOON TSRA, BUT THOSE CONDITIONS WOULD BE BRIEF. LIGHT WINDS WILL BECOME ONSHORE NEAR 10 KT THIS AFTERNOON. DG/KOB && .PREV DISCUSSION... /ISSUED 359 AM EDT FRI AUG 3 2012/ LONG TERM...MONDAY THROUGH THURSDAY...THE CHANCE OF RAIN TAPERS DOWNWARD FROM MIDWEEK ON AS THE ATLC HIGH CENTER MOVES WESTWARD PULLING SOME DRIER AIR OVER S FLA. A DEEP EASTERLY WIND FLOW DICTATES THAT THE HIGHER POPS WILL BE IN THE W INTERIOR AND W COAST. FORECASTED HURRICANE ERNESTO APPROACHES THE YUCATAN PENINSULA BY MID WEEK. AS ERNESTO TRACKS WESTWARD...AT THIS TIME...THE ONLY EFFECT TO S FLA WILL BE AN INCREASE IN THE LOW LEVEL EASTERLY WINDS FROM MIDWEEK ON. BUT KEEP AWARE OF NHC FORECASTS OF THE DEVELOPMENT AND FORECASTED MOVEMENT OF THIS STORM. MARINE...AT THIS TIME...EASTERLY WINDS WILL BE BELOW 15 KNOTS WITH SEAS 3 FEET OR LESS TODAY AND THROUGH THE WEEKEND. WINDS AND SEAS WILL BEGIN TO INCREASE EARLY NEXT WEEK BUT AT THIS TIME NO HIGHLIGHTS ARE EXPECTED. FIRE WEATHER...NO CONCERNS AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 91 79 89 77 / 30 30 50 40 FORT LAUDERDALE 91 79 89 79 / 30 30 50 40 MIAMI 91 78 90 79 / 30 30 50 40 NAPLES 90 77 91 77 / 30 20 50 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ |
| #531465 (Received by flhurricane at: 7:15 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 702 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM THURSDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA WITH POSSIBLE THUNDER...OVER INLAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE CONTINUED DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND THE MID LEVEL DYNAMICS FROM THE VORT...WILL ALL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...LOW PROBABILITIES OF SHRA/TSRA OVERNIGHT. VFR CONDITIONS ARE LIKELY TO GIVE WAY TO MVFR VSBYS BY 08Z AS SKIES CLEAR. CONFIDENCE OF THE TIMING AND DURATION OF IFR LOW BUT GENERALLY FROM 09-11Z. VFR EXPECTED 1-2 HRS AFTER SUNRISE. CONVECTION SHOULD DEVELOP AFT 16Z BUT NO ORGANIZED CONVECTION EXPECTED DUE TO NUMEROUS OUTFLOW BOUNDARY INTERACTIONS. WILL LEAVE MENTION OF CONVECTION FOR LATER TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR...FOLLOWED BY CHANCE FOR SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 700 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WIND DIRECTIONS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531464 (Received by flhurricane at: 7:06 AM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 653 AM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TODAY AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 645 AM FRIDAY...A FEW SHOWERS FORMING IN AREA OF WEAK CONVERGENCE JUST WEST OF OUR CWA AROUND FAYETTEVILLE. HAVE ADDED A SMALL POP FOR THE MORNING HOURS OVER THE FAR SOUTHWESTERN COUNTIES TO ACCOUNT FOR THIS ACTIVITY. REMAINDER OF FORECAST REMAINS UNCHANGED. WEAK UPPER LEVEL LOW TO THE SOUTH WILL GRADUALLY LIFT OUT TO THE NORTH TODAY. THE 500 MB ANALYSIS SHOWED -10 DEG C AT 00Z AND GIVEN THIS RATHER COLD AIR ALOFT AND SOME MODERATE SURFACE-BASED INSTABILITY THIS AFTERNOON WITH CAPES IN THE 1000 TO 1500 J/KG RANGE AND LI`S OF -4 TO -6...WILL FORECAST ISOLATED TSTMS ALONG INLAND AREAS ASSOCIATED WITH THE SEA BREEZE. MAX TEMPERATURES AREA-WIDE SHOULD BE IN THE UPPER 80S TO LOWER 90S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... AS OF 315 AM FRIDAY...THE UPPER AIR PATTERN STARTS TO CHANGE BY LATER TONIGHT AS H5 RIDGE NEAR BERMUDA STARTS TO BUILD WEST WITH STEADY HEIGHT RISES INDICATED OVERNIGHT. ANY CONVECTION SHOULD SHIFT FROM THE LAND TO THE COASTAL AREAS AND OFFSHORE WATERS AND WILL HAVE A SLIGHT CHANCE OVERNIGHT. MINIMUM TEMPERATURES TONIGHT GENERALLY FROM 73 TO 78 DEGREES ACROSS THE REGION. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 245 AM FRI...CONTINUED WITH LITTLE CHANGES TO THE FORECAST OR FORECAST REASONING THROUGH THE LONG TERM. HIGH PRESSURE ALOFT WILL CONTINUE TO EXTEND INTO THE AREA FROM THE WESTERN ATLANTIC THROUGH THE WEEKEND. THE BERMUDA HIGH ALSO STRENGTHENS OFFSHORE ALLOWING MOIST SOUTHERLY FLOW TO CONTINUE THROUGH THE EXTENDED. EXPECT ISOLATED TO SCATTERED DIURNAL CONVECTION INLAND AND ALONG THE SEA BREEZE BOUNDARY THROUGH THE WEEKEND. LOW LEVEL THICKNESSES WILL PERSIST AT 1415-1420 METERS...YIELDING TEMPS NEAR CLIMATOLOGY WITH HIGHS IN THE LOW/MID 90S INLAND TO 80S ALONG THE COAST. A FRONTAL BOUNDARY IS PROGGED TO APPROACH THE AREA FROM THE NORTHWEST MON WITH MOIST SOUTHWESTERLY FLOW AND INCREASING LOW LEVEL SHEAR AHEAD OF A ROBUST MID LEVEL SHORTWAVE. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE MON AFTERNOON/EVENING WITH PWATS AGAIN BUILDING ABOVE 2 INCHES. 12Z OPERATIONAL ECMWF AND GFS INDICATE THE FRONT WILL STALL JUST WEST OF THE REGION ACROSS THE CENTRAL PIEDMONT AND MID ATLANTIC STATES LATE MON THROUGH THURS WHILE AN UPPER TROUGH BECOME RE-ESTABLISHED ACROSS THE EASTERN CONUS. 00Z/12Z ECMWF SUGGEST A WEAK SURFACE LOW WILL FORM ALONG THE FRONT TUES NIGHT AND PUSH NE OFF THE MID ATLANTIC COAST WED INTO WED NIGHT. WILL MAINTAIN CHANCE POPS TUES THROUGH THURS WITH THE UPPER TROUGH AND STALLED SURFACE FRONT CONTINUING ACROSS THE REGION WHILE WEAK SHORTWAVES MOVE THROUGH THE FLOW ALOFT. LOW LEVEL THICKNESSES WILL REMAIN AROUND 1415 METERS MON THROUGH THURS HOWEVER GREATER CLOUD COVER AND PRECIP MAY MODERATE TEMPS FROM REACHING ABOVE THE 90 DEGREE MARK EACH DAY. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 06Z SATURDAY/... AS OF 650 AM FRIDAY...FOG AND STRATUS HAS FAILED TO MATERIALIZE THIS MORNING WITH THE EXCEPTION OF SOME 4 MILE VSBYS AT KOAJ. THIS FOG...AND ANY FOG THAT DEVELOPS AT THE OTHER TAF SITES...SHOULD DISSIPATE QUICKLY WITH VFR CONDITIONS EXPECTED THROUGH TODAY AND INTO TONIGHT. LONG TERM /SATURDAY THROUGH TUESDAY/ AS OF 245 AM FRI...PREDOMINANT VFR AVIATION CONDITIONS EXPECTED THROUGH THE EXTENDED. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN DIURNAL CONVECTION EACH DAY. SOUTHWESTERLY SURFACE FLOW WILL PERSIST INTO EARLY NEXT WEEK WITH HIGH PRESSURE ANCHORED OFFSHORE. A FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST MON NIGHT INTO TUES WITH SHOWERS AND THUNDERSTORMS EXPECTED AHEAD OF AND ALONG THE BOUNDARY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 650 AM FRIDAY...NO MAJOR CHANGES TO MARINE FORECAST AS VERY LIGHT GRADIENT REMAINS IN PLACE. A LIGHT S/SW WINDS AT 10 KNOTS OR LESS WITH A GENTLE SOUTHEAST SWELL COMPONENT WILL MAKE FOR ANOTHER 24 HOURS OF BENIGN MARINE CONDITIONS TODAY AND TONIGHT. WAVEWATCH AND LOCAL SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TODAY AND TONIGHT AND WINDS WILL GENERALLY NOT EXCEED ABOUT 10 OR 12 KNOTS FROM THE SOUTH TO SOUTHWEST THROUGH EARLY SATURDAY MORNING. LONG TERM /SATURDAY THROUGH TUESDAY/ AS OF 245 AM FRI...GOOD BOATING CONDITIONS EXPECTED SAT AND SUN WITH THE BERMUDA HIGH STRENGTHENING OVER THE WESTERN ATLANTIC BRINGING SLY WINDS ACROSS THE WATERS. SPEEDS WILL RANGE GENERALLY 10-15 KNOTS WITH SEAS 2 TO 3 FT. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THE WEEKEND AS WELL. GRADIENT BEGINS TO TIGHTEN LATE SUN AND MON AS FRONTAL SYSTEM APPROACHES FROM THE NW AND EXPECT WINDS TO INCREASE TO AROUND 15-20 KT...MAINLY ACROSS THE NORTHERN AND CENTRAL WATERS. SWAN/WAVEWATCH HAVE BACKED OFF SLIGHTLY WITH SEAS EARLY NEXT WEEK...NOW ONLY BUILDING ABOUT A FOOT OR SO...UP TO 4 FT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ |
| #531463 (Received by flhurricane at: 7:06 AM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 656 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS UPR-LVL LO PRES OVER EASTERN CANADA WITH AN ASSOCIATED TROF WELL EAST OF THE MID ATLANTIC. WEAK CYCLONIC FLOW ALOFT AND EMBEDDED PERTURBATIONS WILL LEAD TO ANOTHER CHC OF SHWRS AND TSTMS THIS AFTN AND EVNG AS THE ATM REMAINS MOIST FROM THE SFC TO 700 MB. ALTHO SHEAR IS VERY WEAK AND FORCING IS LACKING...SOME STORMS MAY BE STRONG AS LO-LVL LAPSE RATES WILL BE VERY STEEP AND LIFTED INDICES ARE PROGGED B/T -4 AND -7 PER LATEST NAM GUIDANCE. TEMPS WILL MAX OUT IN THE LOW TO MID 90S...WITH HEAT INDICES PEAKING IN THE UPR 90S. ANY CONVECTION WILL DISSIPATE TNGT FOLLOWING THE LOSS OF DAYTIME HEATING. LOW TEMPS OVRNGT MAINLY IN THE LOW 70S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 8-10KT TODAY. THE SKY SHOULD BE MOSTLY SUNNY THIS MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531462 (Received by flhurricane at: 6:54 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 645 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHENS OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MINOR ADJUSTMENTS MADE TO CURRENT CONDITIONS...OTHERWISE FORECAST REMAINS ON TRACK. WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS THIS MORNING HOWEVER...REDUCED VISIBILITIES IN BR ARE EXPECTED AT SOME OF THE TERMINALS THROUGH 11Z-12Z. THINKING ANY RESTRICTIONS WILL BE KEPT TO MVFR. AN ISOLATED LOCATION FALLING TO IFR HOWEVER CAN NOT BE RULED OUT. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS MORNING FOR REDUCED VISIBILITY IN FOG. AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS MORNING FOR REDUCED VISIBILITY IN FOG. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS MORNING OR EARLY THIS AFTERNOON FOR TIMING OF SEABREEZE. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...NV/DW |
| #531461 (Received by flhurricane at: 6:53 AM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 641 AM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL INTO EARLY NEXT WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A STATIONARY FRONT WILL STALL NORTH OF THE AREA MID TO LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE REGION WILL REMAIN EMBEDDED WITHIN A BROAD WEAKNESS WITH A MID-LEVEL LOW PROGGED TO REMAIN ALONG THE NORTH CAROLINA COAST. SUNNY SKIES THIS MORNING WILL GIVE A QUICK BOOST TO TEMPERATURES DESPITE A SOMEWHAT COOL START WITH HIGHS STILL EXPECTED TO TOP OUT IN THE LOWER-MID 90S AWAY FROM THE COAST PRIOR TO THE ONSET OF CONVECTION. IT LOOKS TO BE ANOTHER BUSY AFTERNOON WITH LINGERING OUTFLOW BOUNDARIES AND THE SEA BREEZE BEING THE PRIMARY FOCI FOR CONVECTION TO INITIATE. RAP/NAM BUFR SOUNDINGS INDICATE THERE WILL BE PLENTY OF INSTABILITY THIS AFTERNOON WITH SBCAPES NEARING 3000 J/KG AND LIFTED INDICES AS LOW AS -8C. SHEAR PROFILES WILL REMAIN WEAK WITH 0-6KM BULK SHEAR ONLY MAXING OUT AROUND 15 KT DURING PEAK HEATING. WITH THE LACK OF ANY SIGNIFICANT UPPER SUPPORT ALOFT...AIRMASS TSTMS WILL BE PRIMARY DRIVEN BY MESOSCALE INTERACTIONS. MESOSCALE MODELS ARE SIMILAR IN CONCENTRATING TSTMS ACROSS INLAND AREAS BY MID-LATE AFTERNOON AHEAD OF THE SEA BREEZE WITH SOMEWHAT WEAK AGREEMENT WITH A CONVECTIVE MAXIMA COULD SETUP FROM LAKE MOULTRIE THROUGH WALTERBORO TO NEAR SPRINGFIELD. ITS A BIT TOO SOON TO SAY HOW THE MESOSCALE PATTERN WILL EVOLVE...SO WILL REMAIN SOMEWHAT CONSERVATIVE WITH A 20-40 PERCENT POP REGIME DURING THE AFTERNOON HOURS WITH THE HIGHEST GRIDDED POPS PLACED ROUGHLY ALONG A MONCKS CORNER-WALTERBORO-SPRINGFIELD LINE. SHORT TERM HIGHER POPS COULD BE NEEDED LATER TODAY ONCE MESOSCALE TRENDS ARE ESTABLISHED. DCAPES NEAR 1400 J/KG...DELTA EPT/S AROUND +34C...A WINDEX NEAR 65 KT AND A MODERATELY HIGH WET MICROBURST SEVERITY INDEX WILL CERTAINLY SUPPORT A RISK FOR DAMAGING WINDS. SEVERE HAIL IS ALSO A POSSIBILITY WITH ANOMALOUSLY LOW WBZ HEIGHTS IN PLACE FOR EARLY AUGUST. THE CONVECTIVE MODE WILL INITIALLY BE PULSE IN NATURE GIVEN THE WEAK SHEAR PROFILES THAT WILL BE IN PLACE...BUT MAY EVOLVE INTO MORE OF A MULTICELL SCENARIO SHOULD CONVECTIVE OUTFLOWS BEGIN TO INTERACT. PLAN TO HIGHLIGHT A POTENTIAL FOR SEVERE TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... ANY LINGERING CONVECTION WILL DISSIPATE BY LATE EVENING WITH THE LOSS OF INSOLATION AND CONVECTIVE OVERTURNING. CAN NOT COMPLETELY RULE OUT AN ISOLATED SHOWER/TSTM FIRING OVERNIGHT GIVEN THE NATURE OF THE AIRMASS IN PLACE...BUT PROBABILITIES FOR MEASURABLE RAINFALL WILL GENERALLY REMAIN LESS THAN 20 PERCENT. DEPENDING ON HOW QUICKLY DEBRIS CLOUDINESS WILL THIN...PATCHY FOG COULD DEVELOP WITHIN A LIGHT WIND REGIME. LOWS WILL RANGE FROM THE LOWER 70S INLAND TO THE UPPER 70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON. THE SOUTHEAST STATES WILL REMAIN BETWEEN TWO UPPER LEVEL RIDGES THROUGH THE WEEKEND...WITH THE WESTERN RIDGE LOCATED OVER THE CENTRAL PLAINS AND THE EASTERN RIDGE CENTERED OVER THE ATLANTIC WATERS. AT THE SURFACE...ATLANTIC HIGH PRESSURE WILL EXTEND OVER THE MID ATLANTIC AND SOUTHEAST STATES...AS A WEAK INLAND TROUGH TAKES SHAPE BY MONDAY. THIS TYPICAL SUMMERTIME PATTERN WILL SUPPORT A GENERAL SOUTH- SOUTHEAST ONSHORE FLOW AND ALLOW THE DAILY INLAND PROGRESSION OF THE SEABREEZE. EXPECT PULSE TYPE SHOWERS AND THUNDERSTORMS TO INITIATE EACH AFTERNOON AND EVENING...DRIVEN MAINLY BY SEABREEZE CONVERGENCE...MESOSCALE BOUNDARY INTERACTIONS AND DIURNAL HEATING/INSTABILITY. WEAK SHORTWAVE ENERGY ON SATURDAY WILL MOVE OUT OF THE AREA BY SUNDAY AND MONDAY AS THE ATLANTIC RIDGE BUILDS WESTWARD...LEAVING LITTLE UPPER LEVEL SUPPORT THROUGH THE SHORT TERM PERIOD. AS A RESULT...ANY ISOLATED TO SCATTERED CONVECTION WILL DIMINISH IN COVERAGE WITHIN WANING HEATING/INSTABILITY BY SUNSET. HAVE MAINTAIN SHOWER/THUNDERSTORM CHANCES IN THE 20 TO 30 PERCENT RANGE EACH DAY. ALTHOUGH AN ISOLATED STRONG STORM IS POSSIBLE WITH THIS PULSE TYPE CONVECTION AND BOUNDARY INTERACTIONS...THE OVERALL SEVERE WEATHER THREAT WILL REMAIN LOW OVER THE PERIOD. HIGH TEMPERATURES WILL REACH THE LOWER 90S EACH AFTERNOON AWAY FROM THE LOCALLY COOLER COASTLINE...WHILE LOW TEMPERATURES ONLY FALL INTO THE LOW TO MID 70S. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... UPPER LEVEL RIDGING WILL BEGIN TO WEAKEN EARLY NEXT WEEK...AS A TROUGH ALOFT AND SEVERAL SHORTWAVES MOVE ACROSS THE NEW ENGLAND STATES. AN ASSOCIATED COLD FRONT WILL LIKELY STALL WELL TO THE NORTH OF THE FORECAST AREA BY THE MIDDLE OF NEXT WEEK. AT THE SURFACE...THE INLAND TROUGH COULD BECOME MORE PROMINENT BETWEEN SURFACE HIGH PRESSURE OVER THE CENTRAL UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. CONSIDERING THE INCREASED FORCING FROM THE STALLED FRONT TO THE NORTH...COMBINED WITH INFLUENCES FROM THE LEE TROUGH AND BOUNDARY/SEABREEZE INTERACTIONS...CONVECTIVE POTENTIAL COULD BE GREATER THROUGH THE EXTENDED PERIOD. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS...WITH HIGH TEMPERATURES IN THE LOW TO MID 90S DURING THE AFTERNOON FALLING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... SATELLITE SHOWS AN AREA OF STRATUS WITH CIGS AROUND 2500 FT MOVING NORTHEAST AND MAY APPROACH KCHS WITHIN THE NEXT 1-2 HOURS. THE BAND IS FAIRLY TRANSIENT AND MAY ONLY BRIEFLY ESTABLISH A CEILING AT THE TERMINAL...SO MAY OPT NOT TO INCLUDE ANY MENTION. WILL MAKE FINAL DECISION PRIOR TO TAF TRANSMISSION. NO CONCERNS AT KSAV. VFR WILL DOMINATE MUCH OF THE TAF PERIOD AT BOTH KCHS AND KSAV. SCATTERED TSTMS ARE EXPECTED THIS AFTERNOON...MAINLY WEST OF THE TERMINALS SO WILL LEAVE ANY MENTION OUT OF THE 03/12Z TAFS. THE NEED FOR TSRA WILL BE REEVALUATED WITH THE 03/18Z TAF CYCLE. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER THAN 30 PERCENT CONFIDENCE LEVEL AT THIS TIME. && .MARINE... THERE ARE NO MARINE CONCERNS THROUGH TONIGHT. A BROAD SOUTHERLY FLOW REGIME WILL DOMINATE WITH WINDS GENERALLY 10-15 KT AND SEAS 2-3 FT. ATLANTIC HIGH PRESSURE WILL EXPAND OVER THE WATERS THIS WEEKEND...SUPPORTING CONDITIONS BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO EARLY NEXT WEEK. IN GENERAL...SOUTH WINDS BETWEEN 10-15 KT WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE...WITH HIGHEST WINDS EXPECTED NEAR THE INLAND MOVING SEABREEZE CIRCULATIONS AND EARLY NOCTURNAL SURGES. WINDS COULD BRIEFLY BECOME SOUTHEAST EACH AFTERNOON/EVENING AS THE SEABREEZE PUSHES INLAND. SEAS WILL REMAIN BETWEEN 1-3 FT...WITH SWELLS FROM THE SOUTH/SOUTHEAST. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531460 (Received by flhurricane at: 6:38 AM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 626 AM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL APPROACH NEW ENGLAND FROM THE NORTHWEST TODAY, THEN STALL ACROSS THE AREA TONIGHT BEFORE RETURNING NORTH AS A WARM FRONT ON SATURDAY. VERY MUGGY CONDITIONS ARE EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION LATE SUNDAY NIGHT OR MONDAY BRINGING WITH IT THE LIKELIHOOD OF SHOWERS AND STORMS. DRIER AIR THEN RETURNS IN THE WAKE OF THE FRONT MONDAY AFTERNOON INTO MIDWEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 625 AM...MINOR UPDATE FOR 1ST PERIOD HOURLY TEMPS. PREV DISC...WIDESPREAD FOG WAS FORMING IN HUMID AIRMASS CURRENTLY FOUND ACROSS THE FORECAST AREA. AT 06Z...GOES WATER VAPOR IMAGERY SHOWED SHORT WAVE RACING EASTWARD ACROSS THE EASTERN GREAT LAKES. LOW CLOUD AND FOG BURNS OFF QUICKLY THIS MORNING...WITH SOUTHWEST FLOW AHEAD OF SHORT WAVE AND ASSOCIATED SURFACE COLD FRONT WARMING TEMPERATURES TO AROUND 90F WITH EXCEPTION OF MOUNTAINS...AND ALONG THE MID COAST GIVEN ONSHORE TRAJECTORY. SCATTERED CONVECTION WILL DEVELOP TODAY ACROSS THE REGION WITH FORECAST SOUNDINGS INDICATING CAPES OF 1500 J/KG WITH POTENTIAL FOR A FEW STRONG STORMS WITH WINDS THE PRIMARY CONCERN. HAVE ADDED ENHANCED WORDING FOR STRONG GUSTY WIND AND SMALL HAIL TO PM CONVECTION. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... CONVECTION SHOULD QUICKLY END THIS EVENING WITH LOSS OF HEATING AND UPPER SUPPORT. SURFACE FRONT PRESSES SOUTH THEN STALLS AS HIGH PRESSURE BUILDS BY TO OUR NORTH OVERNIGHT INTO THE FIRST HALF OF SATURDAY. THICKER CLOUDS SPREAD NORTH AND EAST ON SATURDAY AS FRONT BEGINS RETURNING NORTH WITH AN INCREASING CHANCE FOR A SHOWER OR THUNDERSTORM AS WE HEAD THROUGH THE DAY. HIGHS SHOULD BE SEVERAL DEGREES COOLER THEN TODAY GIVEN CLOUDS AND AN ONSHORE FLOW. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A WARM AND VERY MOIST AIRMASS WILL BE TRANSPORTED NORTHWARD INTO NORTHERN NEW ENGLAND SATURDAY NIGHT THROUGH SUNDAY NIGHT AS THE AREA WILL BE SANDWICHED IN BETWEEN A LARGE HIGH PRESSURE SYSTEM OVER THE WESTERN ATLC AND AN APPROACHING COLD FRONT FROM THE WEST. THIS MAY MEAN A DECENT AMOUNT OF FOG/HAZE AND STRATUS SATURDAY NIGHT AND SUNDAY NIGHT. DEWPOINTS WILL PROBABLY REACH THE 70-75F RANGE SOMETIME SUNDAY AND SUNDAY NIGHT WHICH WILL MAKE IT VERY MUGGY. AS FAR AS POPS GO...LOOKS MAINLY DRY SATURDAY NIGHT AND SUNDAY ALTHOUGH A FEW THUNDERSTORMS MAY START IMPINGING ON THE AREA LATER SUNDAY AFTERNOON...ESPECIALLY IN NH. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS APPEARS TO BE SUNDAY NIGHT AND MONDAY MORNING WHEN THE SHORT WAVE AND COLD FRONTAL FORCING APPROACHES AND SUBSEQUENTLY MOVES ON THROUGH. THESE THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE VERY HEAVY RAINFALL RATES DUE TO THE VERY MOIST COLUMN. CAN/T RULE OUT A FEW STRONG STORMS AS WELL...ESPECIALLY IN TERMS OF WIND DESPITE BEST FORCING APPROACHING AT NIGHT. FRONT LOOKS TO MOVE OFFSHORE MONDAY WITH THE BEST CHANCE OF SHOWERS AND STORMS BEING IN THE MORNING. HOWEVER...WOULDN/T BE SURPRISED TO SEE THE FRONT ACTUALLY COME THROUGH SLOWER THAN CURRENTLY PROGGED...WHICH COULD MEAN HIGHER POPS MONDAY AFTERNOON AND LESSER POPS SUNDAY NIGHT. THEREAFTER...FAIR AND DRIER WEATHER IS EXPECTED INTO MIDWEEK. && .AVIATION /10Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH SATURDAY/...IFR/LIFR IN FOG...IMPROVING QUICKLY TO VFR THIS MORNING. SCATTERED AFTERNOON/EVENING MVFR IN SHOWERS AND THUNDERSTORMS. SCT IFR FRI NIGHT IN FOG FOLLOWED BY VFR SAT WITH WIDELY SCATTERED MVFR IN ANY PM SHOWERS OR THUNDERSTORMS. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...LOCAL IFR CONDITIONS POSSIBLE IN STRATUS AND FOG SATURDAY NIGHT THROUGH MONDAY MORNING AS VERY MOIST AIRMASS SITS ACROSS THE AREA. BEST CHANCE OF LOW CIGS AND VSBYS WILL BE AT NIGHT. SHOWERS AND STORMS A GOOD BET SUNDAY NIGHT AND MONDAY MORNING. THEREAFTER...CIGS AND VSBYS LOOK TO IMPROVE. && .MARINE... SHORT TERM /THROUGH SATURDAY...NO FLAGS EXPECTED. HOWEVER...LCL VSBY RESTRICTIONS IN FOG AND HAZE...WITH SCATTERED SHOWERS AND THUNDERSTORMS. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...COLD FRONT WILL APPROACH THE WATERS FROM THE WEST SUNDAY NIGHT AND CROSS MONDAY. AHEAD OF THE FRONT...A LONG SOUTHERLY FETCH OF WIND MAY BRING SEAS UP TO SCA LEVELS BY LATER SUNDAY AFTERNOON WHICH COULD LAST THROUGH MONDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ ES |
| #531459 (Received by flhurricane at: 6:38 AM 03.Aug.2012) AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 625 AM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TODAY WITH POSSIBLE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN FOR SATURDAY.&& .NEAR TERM /THROUGH TONIGHT/... UPDATE 0620L: COLD FRONT JUST W AND NW OF THE FA ATTM W/ ASSOCIATED MID/HIGH CLOUDS OVERSPREADING THE REGION WHILE PLENTY OF FOG AND STRATUS CONTS IN THE LOWER LEVELS ACROSS MAINLY ERN AND SRN AREAS... WITHOUT LOCAL RADAR THIS AM BUT USING REGIONAL LOOPS HINTS THAT SOME SHOWER ACTIVITY MAY BE NOW OCCURRING ACROSS WRN AND FAR NRN AREAS AND LATEST OBS AT KFVE SHOWS SOME -RA. STILL EXPECT THE COLD FRONT UPSTREAM TO PUSH SEWRD ACROSS THE FA TODAY W/ SHOWERS AND PSBL TSTMS DVLPG ALONG AND IN ADVANCE OF THIS BNDRY. LATEST 06Z STABILITY INDICES CONT TO SUPPORT CHC FOR A FEW STRONG TO PSBLY SVR TSTMS. CURRENT FCST APPEARS IN GOOD SHAPE ATTM W/ NO MAJOR ADJUSTMENTS NEEDED. MAIN FOCUS FOR TODAY WILL BE ON THE NEXT...SOMEWHAT STRONGER COLD FRONT WHICH CURRENTLY XTNDS NE-SW FROM CENTRAL QUEBEC DOWN INTO THE ERN GRT LAKES AND IS STILL EXPECTED TO SWING SEWRD ACROSS THE REGION LATER TODAY. SFC CONVERGENCE ALONG AND IN ADVANCE OF THIS BNDRY WILL INTERACT W/ TDS IN THE MID TO UPPER 60S AND A HEALTHY UPPER SHORT WAVE TO TRIGGER THE THREAT OF SOME CONVECTION ACROSS THE AREA BY LATE AM INTO THE AFTN W/ ACTIVITY WINDING DOWN FROM NW-SE LATER THIS AFTN AS DRIER AIR BEGINS TO WORK INTO THE REGION. WHILE SHEAR VALS NOT VERY IMPRESSIVE...SFC BASED CAPES JUMP UP NR 2000 J/KG ACROSS CENTRAL/E CENTRAL AREAS BY ERLY AFTN SO EXPECT THE THREAT OF AN ISOLD STRONG TO SVR TSTM CAN NOT BE RULED OUT AND WILL CONT ENHANCED WORDING... SIMILAR TO THE LAST FEW DYS...ANY ERLY AM FOG/STRATUS TODAY SHOULD LIFT/BURN OFF RATHER QUICKLY THIS AM W/ OUR COASTAL AREAS BEING THE SLOWEST TO IMPROVE. A MORE SWRLY LOW-LEVEL FLOW SHOULD ALLOW HIGH TEMPS TO REACH THE LOWER TO MID 80S N AND MID TO UPPER 80S S AWAY FROM THE COAST... WHILE DRIER AIR OVERSPREADS THE AREA FROM NW-SE TNGT...CLRG SKIES AND LGT WINDS WILL ALLOW FOR SIGNIFICANT COOLING LIKELY ALLOWING TEMPS TO REACH TDS AND INCREASING THE POTENTIAL FOR SOME FOG AGAIN TNGT. IN THESE SCENARIOS IT IS ALWAYS A RACE BTWN THE DRYING AND COOLING AND WHICH FACTOR WINS OUT. FOR NOW...WILL CARRY PATCHY FOG N AND CENTRAL W/ AREAS DOWNEAST AS THESE WILL BE THE LAST TO SEE THE DRIER AIR... EXPECT LOWS TNGT TO BE SIGNIFICANTLY COOLER THAN THE LAST FEW DYS...AT LEAST FOR OUR CENTRAL AND NRN AREAS W/ LOWS RANGING FROM THE LOWER TO MID 50S N TO THE LOWERS 60S S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... EXPECT THE WEEKEND TO BE MAINLY DRY WITH ABOVE NORMAL TEMPERATURES AS HIGH PRESSURE BUILDS OVER THE REGION. SATURDAY WILL START OUT MOSTLY SUNNY, BUT CLOUDS WILL INCREASE FROM THE SOUTH LATE IN THE DAY AS A WARM FRONT LIFTS NORTHWARD. THIS BOUNDARY WILL MOVE ACROSS THE STATE SATURDAY NIGHT AND MAY PRODUCE A FEW SHOWERS OVER THE HIGHER TERRAIN AS IT DOES SO. MUGGIER AIR WILL SPREAD INTO THE REGION BEHIND THE FRONT WITH A RETURN OF MID 60S DEWPOINTS BY SUNDAY AFTERNOON. A COLD FRONT WILL APPROACH THE REGION FROM QUEBEC SUNDAY AFTERNOON, BUT MOST OF THE PRECIPITATION WILL HOLD OFF UNTIL LATE IN THE DAY, EXCEPT PERHAPS IN FAR WESTERN AREAS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE AFOREMENTIONED COLD FRONT WILL MOVE THROUGH THE STATE LATE SUNDAY NIGHT INTO MONDAY MORNING. THE TIMING OF THE FRONTAL PASSAGE IS NOT OPTIMAL FOR INSTABILITY, THOUGH 0-6 KM SHEAR INCREASES TO AROUND 30 KT JUST AHEAD OF THE FRONT. DOWNEAST AREAS WOULD HAVE THE BEST CHANCES OF SEEING ANY ORGANIZED CONVECTION, AS STORMS WOULD MOST LIKELY BE ELEVATED ACROSS THE NORTH. ALSO OF CONCERN IS INCREASING MOISTURE TRANSPORT AHEAD OF THE FRONT; MODELS ARE INDICATING PWATS OF 2+ INCHES AREAWIDE SUNDAY NIGHT INTO MONDAY MORNING. IN ADDITION, THE WARM CLOUD LAYER LOOKS TO BE DEEP, AROUND 13-14 KFT. THIS MEANS THAT ANY STORMS WOULD BE CAPABLE OF PRODUCING HEAVY RAIN. ONCE THE FRONT GOES BY, HIGH PRESSURE AND DRIER WEATHER RETURNS MONDAY NIGHT AND TUESDAY. THEN ANOTHER COLD FRONT WILL GRADUALLY MOVE SOUTH TUESDAY NIGHT, BECOMING NEARLY STATIONARY NEAR THE SAINT JOHN VALLEY WEDNESDAY BEFORE FINALLY PUSHING SOUTH INTO DOWNEAST MAINE WEDNESDAY NIGHT/THURSDAY. THE LONGER-TERM MODELS ARE SHOWING SOME DIFFERENCES IN TIMING OF THIS FEATURE AND ITS ASSOCIATED PRECIPITATION, SO HAVE STUCK WITH 20-30 POPS FOR MID WEEK. TEMPERATURES WILL BE SEASONABLE THROUGH THE WEEK. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... NEAR TERM: ALL TAF SITES IFR ATTM XCPT KPQI WHICH IS CURRENTLY MVFR. THIS RATHER IRONIC CONSIDERING A TSTM DROPPED SIGNIFICANT RAINFALL ON PQI THU AFTN WHERE MOST OTHER AREAS SO LITTLE OR NO RAINFALL... IN ANY CASE...THINK KPQI WILL JOIN THE REST SHORTLY. IFR CONDS SHOULD THEN PERSIST INTO THE AM HRS SIMILAR TO LAST SEVERAL DAYS W/ KBHB NEAR THE SRN COAST THE SLOWEST TO IMPROVE. DESPITE THE PASSAGE OF A COLD FRONT LATER TODAY AND THE INFLUX OF LOWER TDS...LGT WINDS BEHIND THE FRONT TNGT AND CLR SKIES WILL LEAD TO GOOD COOLING AND WILL LIKELY RESULT IN PATCHY FOG ACROSS THE NRN TAF SITES W/ MORE WDSPRD FOG S... SHORT TERM: VFR IS EXPECTED THROUGH THE WEEKEND, WITH EXCEPTION OF IFR DUE TO PATCHY FOG LATE SATURDAY NIGHT, ESPECIALLY AT THE TERMINALS. A COLD FRONT WILL MOVE ACROSS THE AREA EARLY MONDAY, PRODUCING SHOWERS AND THUNDERSTORMS. WHILE VFR SHOULD PREVAIL THROUGH MIDWEEK, MVFR CONDITIONS ARE POSSIBLE IN ANY PRECIPITATION SUNDAY NIGHT AND MONDAY. && .MARINE... NEAR TERM: WINDS/SEAS SHOULD REMAIN BLO SCA LEVELS THRU TNGT. FOG WILL CONT TO BE AN ISSUE THRU TNGT. SHORT TERM: A SMALL CRAFT ADVISORY MAY BE NEEDED LATE SUNDAY THROUGH MONDAY AS SOUTH WINDS INCREASE AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL BE BORDERLINE /GUSTS AROUND 20 KT/ BUT WAVES LOOK TO REACH 5-6 FT LATE SUNDAY EVENING AND REMAIN SO INTO EARLY MONDAY NIGHT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...KHW |
| #531458 (Received by flhurricane at: 6:29 AM 03.Aug.2012) AFDBRO AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BROWNSVILLE TX 518 AM CDT FRI AUG 3 2012 .DISCUSSION...AN ERROR OCCURED DURING SOME PROCEDURE CHECK OF THE GRIDS BEFORE ISSUANCE OF EARLIER FORECAST PACKAGE. HIGH TEMPERATURES ON SATURDAY WHERE SOMEHOW LOWERED BY 2 TO 5 DEGREES OVER WHAT THEY SHOULD DEPICT. A CORRECTED VERSION IS OUT AND THE TEMP/POP TABLE BELOW HAS BEEN UPDATED. WE APOLOGIZE FOR ANY FOR ANY INCONVENIENCE THAT THIS MAY HAVE OCCURRED. && .PREV DISCUSSION... /ISSUED 345 AM CDT FRI AUG 3 2012/ SHORT TERM /TODAY THROUGH SATURDAY/...LATEST MODEL PACKAGE SHOWS LITTLE CHANGE IN UPPER RIDGE STRUCTURE OVER THE NEXT 36 HOURS. THE CENTER OF THE DEEP LAYERED RIDGE TO REMAIN OVER NORTH CENTRAL TO NORTHWEST TEXAS MAINTAINING STRONG SUBSIDENCE AIR ACROSS SOUTH TEXAS. PLENTY OF HEAT AND DRY AIR TO REMAIN IN PLACE TODAY AND SATURDAY WITH LITTLE TO NO RAIN EXPECTED. ANY ADDED MOISTURE ON SATURDAY IS NOT LIKELY TO KICK OFF ANYTHING MORE THEN ONE OR TWO SHOWERS OR THUNDERSTORMS. WARM AIR ALOFT TO MAINTAIN A CAP. INVERTED TROUGH THAT HAS BEEN TALKED ABOUT HAS BECOME STRETCHED OUT AND WEAKER AND STRONGER THEN USUAL SOUTH WINDS ARE NOT CONDUCIVE FOR AN ACTIVE SEA BREEZE. WITH THIS SAID...LOWERED SATURDAY POPS BELOW 20 PERCENT WITH KENEDY COUNTY THE BEST AREA TO SEE ISOLATED CONVECTION. TEMPERATURES TO REMAIN WELL ABOVE NORMAL WITH GOING FORECAST REMAINING ABOVE ALL GUIDANCE VALUES. SOUTHEAST WINDS TO INCREASE FRIDAY AND SATURDAY AFTERNOON WITH INLAND AREAS SEEING GUSTS BETWEEN 25 TO 30 MPH. LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...PATTERN SHIFT NEXT WEEK STILL EXPECTED TO BRING SOME CHANGES TO THE STAGNANT DOLDRUMS THAT HAVE BEEN THE PAST WEEK. THE UPPER RIDGE WILL SHIFT WESTWARD TO THE FOUR CORNERS REGION STARTING SUNDAY...TAKING THE CORE OF THE SUBSIDENCE WITH IT. AN INVERTED TROUGH WILL SHARPEN ACROSS THE SOUTHEASTERN US AND CHASE THE RIDGE WESTWARD ACROSS THE NORTHERN GULF. THIS WILL INTRODUCE DEEPER MOISTURE. THIS MOISTURE AND INSTABILITY FROM THE TROUGH WILL ALLOW THE SEABREEZE TO ACTIVATE EACH DAY AND PERSIST THROUGH THE WEEK. TEMPERATURES WILL REMAIN ABOVE NORMAL...BUT WILL BE HELD DOWN SLIGHTLY DUE TO DEEPER MOISTURE IN THE REGION. AS THE RIDGE MOVES WEST...THE HEAT LOW THAT HAS PERSISTED IN NORTH TEXAS WILL ALSO DEPART...ALLOWING WINDS TO SLACKEN FOR MOST OF THE WEEK. MARINE...NOW THROUGH SATURDAY...LOCAL PRESSURE GRADIENT WILL CONTINUE TO PRODUCE SMALL CRAFT EXERCISE CAUTION WINDS MAINLY OVER THE OPEN GULF DURING THE OVERNIGHT HOURS AND ACROSS THE LAGUNA DURING THE LATE MORNING AND AFTERNOON HOURS. A FEW AREAS NEAR PORT MANSFIELD COULD SEE INTERMITTENT SMALL CRAFT ADVISORY CONDITIONS BUT DURATION IS NOT LIKELY TO BE LONG ENOUGH TO WARRANT AN ADVISORY AT THIS TIME. SEAS CONSIST OF MAINLY WIND WAVES WHICH WILL FLUCTUATE 1 TO 3 FEET DURING THE DAY AND 3 TO 5 FEET OVERNIGHT. SATURDAY NIGHT THROUGH WEDNESDAY...LOW PRESSURE THAT HAS BEEN MEANDERING ACROSS NORTH TEXAS WILL WEAKEN AND SHIFT FURTHER WEST FOR THE EXTENDED PERIOD...ALLOWING WINDS TO SLACKEN TO AROUND 10 KNOTS. THIS WILL BRING LIGHTER SEAS 3 FEET OR LESS FOR THE FORECAST PERIOD. SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE EACH DAY DUE TO INSTABILITY ALOFT AND DEEPER MOISTURE. FIRE WEATHER...ENHANCED FIRE DANGER CONDITIONS WILL BE POSSIBLE MAINLY FROM 281 WESTWARD TODAY AND SATURDAY AFTERNOON. DRY AIR LOFT TO MIX DOWN TO THE SURFACE WITH DEW POINTS AND RELATIVE HUMIDITY VALUES TO FALL RAPIDLY THROUGH THE AFTERNOON. RH VALUES TO DROP BETWEEN 20 AND 30 PERCENT AND POSSIBLY BELOW 20 PERCENT IN ZAPATA, STARR AND JIM HOGG COUNTIES. 20FT WINDS ARE EXPECTED TO BE BELOW CRITICAL FIRE DANGER LEVELS...BUT CRITICAL GROWTH CONDITIONS ARE WARRANTED AS GUSTS RANGE FROM 20 TO 25 MPH LATE IN THE AFTERNOON AND VEGETATION REMAINS VERY DRY. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 95 81 95 81 / 10 10 10 20 BROWNSVILLE 97 80 96 79 / 10 10 10 10 HARLINGEN 101 78 100 78 / 10 10 10 10 MCALLEN 104 79 102 79 / 0 0 10 10 RIO GRANDE CITY 105 80 103 79 / 0 0 0 10 SOUTH PADRE ISLAND 87 81 89 82 / 10 10 10 20 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531457 (Received by flhurricane at: 6:18 AM 03.Aug.2012) AFDSJU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 614 AM AST FRI AUG 3 2012 .SYNOPSIS...AT 5 AM AST...TROPICAL STORM ERNESTO WAS LOCATED NEAR LATITUDE 13.5 NORTH...LONGITUDE 60.7 WEST AND WAS MOVING TOWARD THE WEST AT NEAR 24 MPH. ERNESTO IS EXPECTED TO MOVE GENERALLY WEST FOR THE NEXT COUPLE OF DAYS...WITH A GRADUAL DECREASE IN FORWARD SPEED. ON THE FORECAST TRACK...ERNESTO WILL MOVE ACROSS THE EASTERN CARIBBEAN TODAY THROUGH SATURDAY...EVENTUALLY BRINGING OUTER BANDS OF MOISTURE TO THE LOCAL AREA...WITH CLOUDINESS...SHOWERS AND THUNDERSTORMS AND INCREASINGLY BREEZY TO WINDY CONDITIONS. && .DISCUSSION...AS THE PREVIOUS FORECASTER HAD ALLUDED TO... ALTHOUGH THE CENTER OF ERNESTO IS EXPECTED TO PASS A SAFE DISTANCE TO THE SOUTH OF THE LOCAL AREA...THE COMBINATION OF THE FORECASTED STRENGTHENING OF ERNESTO AND STRENGTHENING SURFACE HIGH PRESSURE NORTH NORTHEAST OF THE LOCAL AREA...WILL RESULT IN A TIGHTENING LOCAL PRESSURE GRADIENT...PRODUCING INCREASING FRESH TO LOCALLY STRONG WINDS ACROSS THE LOCAL ISLANDS...WITH BREEZY TO LOCALLY WINDY CONDITIONS EXPECTED. IN ADDITION...MOISTURE ON THE NORTH AND EAST SIDES OF THE SYSTEM...WILL BE PULLED UP ACROSS THE FA... RESULTING IN INCREASINGLY ACTIVE CONDITIONS LOCALLY BEGINNING LATE THIS AFTERNOON/EARLY THIS EVENING IN THE EAST AND THEN SPREADING WEST NORTHWEST. STILL LOOKS LIKE THE STRONGEST WINDS AND MOST SIGNIFICANT BANDS OF SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS ST CROIX...VIEQUES...THE SOUTH HALF OF PUERTO RICO AND THE ADJACENT COASTAL WATERS TONIGHT THROUGH SATURDAY...BUT WITH ALL AREAS RECEIVING INCLEMENT CONDITIONS. GIVEN WIND GUIDANCE VALUES (WHICH WE REMAIN AT LEAST 5 KNOTS BELOW IN THE GRIDS)...STILL APPEARS THAT A FEW AREAS COULD NEED A WIND ADVISORY LATE TONIGHT THROUGH SATURDAY AFTERNOON. IN TERMS OF RAINFALL...DESPITE THE RATHER QUICK AND MAINLY WESTWARD MOTION OF ERNESTO...MODELS CONTINUE TO INDICATE A GOOD SLUG OF DEEP TROPICAL MOISTURE BEING PULLED UP ACROSS THE FA AND LONG TERM SATELLITE LOOPS AND TPW PRODUCT...SHOW THE OVERALL MOISTURE ENVELOPE OF THE SYSTEM LIFTING/GROWING WEST NORTHWEST IN SUCH A MANNER...THAT A GENERAL 6 TO 12 HOUR PERIOD OF ACTIVE WEATHER SHOULD ENCOMPASS THE LOCAL ISLANDS. WE BELIEVE THAT EARLIER RAINFALL ESTIMATES OF A FEW INCHES OVER PARTS OF EAST AND SOUTH PUERTO RICO SHOULD VERIFY...WITH A COUPLE OF SPOTS POSSIBLY RECEIVING 5 INCHES AND GENERALLY LESSER AMOUNTS TO THE NORTH AND WEST. && .AVIATION...VFR CONDITIONS EXPECTED AT ALL LOCAL TAF SITES THROUGH THE FORECAST PERIOD. LLVL WINDS WILL REMAIN FROM THE NORTHEAST THRU TONIGHT...VEERING FROM THE EAST TO SOUTHEAST EARLY SATURDAY THRU SUNDAY. SUSTAIN WINDS OF 15 TO 25 KTS WITH HIGHER GUSTS UP TO 40 KTS ARE POSSIBLE DURING THE WEEKEND AS TS ERNESTO MOVES SOUTH OF THE FA. OUTER BANDS OF TS ERNESTO MAY AFFECT THE ISLANDS BTWN 04/06Z AND AT LEAST 05/12Z. && .MARINE...EXPECT INCREASING FRESH TO STRONG WINDS AND BUILDING HAZARDOUS SEAS ACROSS MOST OF THE LOCAL COASTAL WATERS...SPREADING WEST NORTHWEST FROM THE ANEGADA PASSAGE AND SOUTHEAST CARIBBEAN LATE THIS AFTERNOON/EARLY TONIGHT AND THEN EXPANDING ACROSS MOST AREAS. THE WORST CONDITIONS...WITH SUSTAINED WINDS OF 21 TO 27 KNOTS WITH GUSTS OF 35 TO 40 KNOTS AND SEAS BUILDING TO 7 TO 10 FEET SHOULD BE REALIZED ACROSS PARTS OF THE ANEGADA PASSAGE... LOCAL CARIBBEAN WATERS AND THE MONA PASSAGE...WITH SLIGHTLY LESS WIND AND LOWER SEAS TO THE NORTH. SMALL BOAT OPERATORS SHOULD EXERCISE CAUTION ACROSS THESE AREAS TODAY...WITH SMALL CRAFT ADVISORIES BEGINNING THIS EVENING/TONIGHT AND ALSO EXPANDING WEST NORTHWEST. FOR FORECAST MARINE CONDITIONS...PLEASE REFER TO OUR LOCAL MARINE PRODUCTS. && .PRELIMINARY POINT TEMPS/POPS... SJU 88 78 86 78 / 50 80 80 60 STT 81 80 84 80 / 50 50 50 30 && .SJU WATCHES/WARNINGS/ADVISORIES... PR... VI...NONE. COASTAL WATERS...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM AST SUNDAY FOR ANEGADA PASSAGE SOUTHWARD TO 17N. SMALL CRAFT ADVISORY FROM 11 AM TO NOON AST SATURDAY FOR COASTAL WATERS OF NORTHERN PUERTO RICO OUT 10 NM-COASTAL WATERS OF NORTHWESTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM AST SUNDAY FOR COASTAL WATERS OF SOUTHERN USVI VIEQUES AND EASTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO NOON AST SUNDAY FOR CARIBBEAN WATERS OF PUERTO RICO FROM 10 NM TO 17N. SMALL CRAFT ADVISORY FROM 2 AM SATURDAY TO NOON AST SUNDAY FOR COASTAL WATERS OF SOUTHERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM NOON SATURDAY TO NOON AST SUNDAY FOR COASTAL WATERS OF SOUTHWESTERN PUERTO RICO OUT 10 NM. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON AST SUNDAY FOR ATLC WATERS OF PUERTO RICO AND USVI FROM 10NM TO 19.5N- MONA PASSAGE SOUTHWARD TO 17N. SMALL CRAFT ADVISORY FROM 6 AM SATURDAY TO 6 AM AST SUNDAY FOR COASTAL WATERS OF NORTHERN USVI AND CULEBRA OUT 10 NM. && $$ |
| #531456 (Received by flhurricane at: 5:20 AM 03.Aug.2012) AFDMOB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 410 AM CDT FRI AUG 3 2012 .SHORT TERM [TODAY AND TONIGHT]...CONTINUE TO SEE VERY LITTLE CHANGE IN THE LARGE SCALE PATTERN WITH AMPLIFIED MID LEVEL RIDGE HOLDING STRONG OVER TEXAS AND A TROF FROM THE MID ATLANTIC SOUTHWARD ACROSS FLORIDA. SURFACE ANALYSIS SHOWS A STALLED FRONTAL ZONE DRAPED FROM THE OHIO RIVER VALLEY BACK ACROSS OKLAHOMA/NORTH TEXAS. WATER VAPOR IMAGERY SHOWS A WELL DEFINED RING OF MOISTURE AROUND THE TEXAS HIGH LEVEL RIDGE...WHERE FORECASTERS HAVE SEEN QUITE A BIT OF LIGHTNING ACTIVITY FROM WESTERN MEXICO UP THROUGH THE CENTRAL PLAINS AND DOWN INTO THE SOUTHEAST FROM THE PAST AFTERNOON. THE MOISTURE PATTERN HOLDS WITH BUFR FORECAST SOUNDINGS SHOWING PRECIPITABLE WATER VALUES AROUND 2 INCHES. CONSIDERING THIS LONG WITH ENVIRONMENTAL INSTABILITY AND MID LEVEL IMPULSES THAT MOVE OUT OF THE MID SOUTH...SINKING SOUTHWARD ACROSS THE FORECAST AREA....FORECASTERS EXPECT ANOTHER ROUND OF SCATTERED SHOWERS/STORMS TO FORM DURING THE DAY. THERE IS A DIFFERENCE OF OPINION BETWEEN THE NAM/GFS ON DEGREE OF INSTABILITY WITH THE GFS HIGHEST...SHOWING MOST UNSTABLE ENVIRONMENTAL VALUES BETWEEN 3000 AND 4000 J/KG. GIVEN LITTLE TO NO CHANGE IN PATTERN...THE GFS OUTPUT SEEMS MORE PLAUSIBLE. TAKING A LOOK AT THE HIGHER RESOLUTION WRF...CONVECTIVE INITIATION LOOKS TO BEGIN ALONG THE COAST BY AND AFTER 11 AM. THE HRRR ALSO SUPPORTS THIS. AS HAS BEEN THE CASE FOR THE PAST SEVERAL DAYS...STORMS CAN BE STRONG AND CAPABLE OF FREQUENT...POTENTIALLY DEADLY LIGHTNING...STRONG WIND GUSTS FROM 45 TO 55 MPH...LOCALLY HEAVY RAINS AND SMALL HAIL. A FEW COULD ALSO INTENSIFY BRIEFLY TO SEVERE LEVELS WITH DAMAGING WINDS IN EXCESS OF 60 MPH AND HAIL TO AROUND QUARTER SIZE. STORM MOTION IS FORECAST TO BE GENERALLY SOUTHWARD AT 15 TO 20 MPH. BEFORE THE ONSET OF STORMS...HIGHS TODAY FORECAST INTO THE MID 90S OVER THE INTERIOR AND CLOSER TO 90 ALONG THE COAST. TONIGHT`S LOWS IN THE LOWER/MID 70S. /10 THE WET MICROBURST RISK FOR TODAY IS HIGH. [THIS WEEKEND]...WE WILL START OFF THE UPCOMING WEEKEND WITH AN AREA OF UPPER WEAKNESS OVER THE EASTERN HALF OF THE FORECAST AREA SITUATED BETWEEN TWO LARGE UPPER HIGHS...ONE OVER THE SOUTHERN PLAINS AND ONE OVER THE WESTERN ATLANTIC. THIS UPPER WEAKNESS...IN THE FORM OF AN INVERTED TROUGH...WILL CREEP SLOWLY WESTWARD THROUGH MONDAY MORNING AS AN UPPER TROUGH MOVES ACROSS THE NORTHEAST CONUS AND THE SOUTHERN PLAINS HIGH RETROGRADES TOWARD THE WEST. WE WILL CONTINUE TO SEE SEVERAL DISTURBANCES ROUNDING THE EASTERN PERIPHERY OF THE SOUTHERN PLAINS UPPER HIGH...AND APPROACH THE FORECAST AREA FROM THE NORTH...RESULTING IN A MAINLY DIURNAL PATTERN OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE WEEKEND. THE ENVIRONMENT WILL ALSO REMAIN FAVORABLE FOR STRONG TO POSSIBLY SEVERE CONVECTION BOTH AFTERNOONS AS MLCAPES APPROACH 2000 TO 2500 J/KG ACROSS THE ENTIRE FORECAST AREA. MAIN THREATS WILL MAINLY BE STRONG WET MICROBURST WINDS...LIGHTNING...AND PROLONGED PERIODS OF HEAVY RAIN AND LOCALIZED FLOODING DUE TO A SLOWER AND ERRATIC MOVEMENT OF THE STORMS. HIGH TEMPERATURES BOTH DAYS WILL REMAIN NEAR NORMAL...RANGING FROM 87 TO 92 DEGREES. HIGHEST AFTERNOON HEAT INDICES WILL RANGE FROM 96 TO 101 DEGREES. LOWS BOTH NIGHTS WILL BE IN THE LOWER TO MID 70S INLAND AREAS...WITH UPPER 70S ALONG THE BEACHES. AS FOR TROPICAL STORM ERNESTO...THE OFFICIAL FORECAST DOES HAVE THE SYSTEM MOVING ACROSS THE CARIBBEAN SEA OVER THE WEEKEND...AND STRENGTHENING INTO A HURRICANE SOUTH OF JAMAICA BY MIDNIGHT SUNDAY NIGHT. THE EXPECTED INCREASE IN INTENSITY OF ERNESTO IS ATTRIBUTED TO THE SYSTEM MOVING INTO AN AREA OF VERY LOW WIND SHEAR AND OVER SEA SURFACE TEMPERATURES NEAR 83 DEGREES. /22 && .LONG TERM [MONDAY THROUGH THURSDAY]...ERNESTO IS FORECAST TO CONTINUE ON ITS WESTWARD TRACK AS A HURRICANE THROUGH EARLY NEXT WEEK...REACHING NEAR THE TIP THE YUCATAN PENINSULA TUESDAY NIGHT. IN THE MEANTIME...THE UPPER WEAKNESS WILL REMAIN OVER THE FORECAST AREA THROUGHOUT THE LONG TERM. TYPICAL MID SUMMER CONVECTION WILL PERSIST THROUGH THE LONG TERM...WITH MAINLY DIURNAL DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS FORECAST EACH DAY AS NUMEROUS DISTURBANCES CONTINUE TO MOVE OVER THE FORECAST AREA. HIGH TEMPERATURES EACH DAY WILL REMAIN NEAR OR SLIGHTLY ABOVE NORMAL RANGING FROM 90 TO 95 DEGREES. HIGHEST AFTERNOON HEAT INDICES EACH AFTERNOON WILL CONTINUE TO RANGE FROM 96 TO 101 DEGREES. LOWS EACH NIGHT THROUGH THE ENTIRE LONG TERM WILL BE IN THE LOWER TO MID 70S INLAND AREAS...WITH UPPER 70S ALONG THE BEACHES. /22 && .AVIATION [03.12Z KMOB/KBFM/KPNS TAF ISSUANCES]...EXPECT OCCASIONAL IFR CONDITIONS DUE TO CIGS/VSBYS IN SCATTERED TSRA MAINLY AFTER 16Z. ALTHOUGH TSRA WILL BE FORMING OVER LAND WHILE MOVING SOUTH DURING THE LATE MORNING AND EARLY AFTERNOON HOURS...THE ENHANCEMENT OF TSRA ALONG THE COAST DUE TO THE SEABREEZE WILL PROVIDE SLIGHTLY MORE COVERAGE ACROSS COASTAL TERMINALS. /10 && .MARINE...A BROAD RIDGE OF SURFACE HIGH PRESSURE OVER THE SOUTHWEST ATLANTIC NOSES WESTWARD INTO THE GULF THROUGH THE EARLY HALF OF NEXT WEEK. THIS WILL MAINTAIN A GENERAL LIGHT ONSHORE FLOW WITH SIGNIFICANT WAVE HEIGHTS 2 FEET OR LESS. WINDS...WAVES AND SEAS LOCALLY HIGHER NEAR STORMS. /10 && .FIRE...SURFACE HIGH PRESSURE WILL REMAIN OVER THE GULF THROUGH THE WEEKEND WITH A LIGHT SOUTH TO SOUTHWESTERLY FLOW EXPECTED. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE FORECAST MAINLY DURING THE AFTERNOONS THROUGH THE WEEKEND AS WELL. DISPERSIONS WILL BE FAIR TO GOOD IN THE AFTERNOON PRIMARILY DUE TO HOT TEMPERATURES AND DEEP MIXING HEIGHTS. FOG POTENTIAL AND OTHER REMARKS...LIGHT PATCHY FOG IS POSSIBLE DURING THE EARLY MORNING HOURS...BUT IS NOT FORECAST TO BE A WIDESPREAD CONCERN. /22 && .PRELIMINARY POINT TEMPS/POPS... MOBILE 92 76 88 74 / 50 20 60 30 PENSACOLA 90 75 88 76 / 50 20 50 30 DESTIN 90 77 87 77 / 40 20 40 30 EVERGREEN 94 73 87 72 / 50 30 60 30 WAYNESBORO 94 74 90 73 / 50 20 60 30 CAMDEN 94 75 89 73 / 50 30 60 30 CRESTVIEW 93 73 87 71 / 50 20 60 30 && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$ |
| #531455 (Received by flhurricane at: 5:18 AM 03.Aug.2012) AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 415 AM CDT FRI AUG 3 2012 .DISCUSSION... SHORT TERM WX WILL BE STATUS QUO WITH STRONG H5 TROF CENTERED OVER N TX. THIS RIDGE IS FCST TO GRADUALLY SHIFT NWWD LATE IN THE WEEKEND AND INTO NEXT WEEK. INCREASED MOISTURE...COOLER H85 & H7 TEMPS...SEABREEZE AND IMPULSES ROTATING AROUND THE ERN PERIPHERY OF THE RIDGE SHOULD ALLOW FOR RAIN CHANCES TO BE RE-INTRODUCED INTO THE FCST. ATTM...MODELS PAINTING MONDAY AS HAVING THE MOST RAIN COVERAGE AND WILL TREND POPS ACCORDINGLY. STORM MOTION LOOKS TO BE ON THE SLOW SIDE (EVEN ON SUNDAY) SO THOSE THAT DO SEE THE PRECIP MIGHT SEE SOME LOCALIZED HIGHER AMOUNTS. FROM MIDWEEK ON...MEDIUM RANGE MODELS SHOW RIDGE CENTERED FROM THE ROCKIES INTO THE PLAINS....FAR ENOUGH AWAY TO ANTICIPATE SOME ISO SHRA/TSTM CHANCES EACH DAY. FLY IN THE OINTMENT OF COURSE IS WHAT TS ERNESTO DECIDES TO DO. VARIETY OF MODEL SOLNS OUT THERE...NONE OF WHICH CAN BE TAKEN TO THE BANK THIS FAR OUT - STILL A WEEK OUT IF IT WERE TO IMPACT US. 47 && .MARINE... FOR THE MOST PART...IT LOOKS LIKE ONSHORE WINDS WILL PREVAIL ACROSS THE COASTAL WATERS THROUGH THE FCST PERIOD. S/SWLY WINDS TODAY WILL BE SHIFTING TO THE E/SE LATE SUN/MON AS THE UPPER RIDGE MOVES A BIT NORTH. THE PATTERN CHANGE WILL ALSO HELP TO INCREASE RAIN CHCS WITH S/WV ACTIVITY APPROACHING FROM THE EAST (UNDER THE RIDGE). MARINERS SHOULD ALSO KEEP AN EYE ON THE TRACK OF TROPICAL STORM ERNESTO. 00Z FCSTS ARE INDICATING THAT THE SYSTEM MIGHT BRING IMPACTS TO THE UPR TX COASTAL WATERS LATE NEXT WEEK. STAY TUNED! 41 && .AVIATION... VFR WITH SHORT LIVED PERIODS OF MVFR CIGS AOA SUNRISE FOR THE USUAL SITES. INCREASED POPS LATE SAT/SUN BUT TIMING REMAINS AN ISSUE. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 99 77 98 77 98 / 0 0 10 10 20 HOUSTON (IAH) 96 78 95 78 95 / 0 0 20 10 30 GALVESTON (GLS) 92 82 92 82 91 / 0 0 20 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531454 (Received by flhurricane at: 5:11 AM 03.Aug.2012) AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 405 AM CDT FRI AUG 3 2012 .SHORT TERM... UPPER LEVEL RIDGE TO THE WEST OF THE AREA CONTINUES TO BE THE CONTROLLING FACTOR FOR LOCAL CONDITIONS. TEMPERATURES AND DEWPOINTS ARE IN GENERAL ABOUT A DEGREE OR SO COOLER AREAWIDE. LOOKING UPSTREAM...NOT MUCH IN THE WAY OF THICK CLOUD COVER AS WHAT OCCURRED YSTRDY. SO NOT THINKING THAT HIGHS WILL BE LIMITED AS MUCH AND SHOULD REACH CLOSER TO FCST. HAVE BUMPED UP TD/S FROM GUIDANCE DUE TO ITS LOW BIAS ALL WEEK LONG. COMBINATION OF T/TD WILL ONCE AGAIN BRING HEAT INDICIES RIGHT TO 100 TO 105 RANGE. HAVE QUITE WIDE RANGE IN GUIDANCE ON POPS TODAY. MAV IS ON THE DRIER SIDE WITH GENERALLY 20 PERCENT ACROSS THE AREA. MET/NAM IS MUCH HIGHER AT 50 TO 60 PERCENT AND ECMWF IS AROUND 40. MET/NAM JUST SEEMS TO BE WAY TO AGGRESSIVE...ESPECIALLY WHEN CONSIDERING HOW LITTLE CONVECTION HAS ACTUALLY DEVELOPED OVER THE LAST FEW DAYS. REALLY DONT SEE MUCH IN THE WAY OF A SIGNIFICANT SHORTWAVE NORTH OF THE AREA TO PRODUCE WIDESPREAD DEVELOPMENT. WHAT WILL MORE THAN LIKELY OCCUR IS JUST A FEW STORMS DEVELOPING ALONG SEA BREEZE AND OTHER BOUNDARIES LEFT OVER FROM YSTRDY. SO HAVE GONE WITH THE DRIER MAV FOR POPS TODAY. PROBABLY WILL BE JUST AS UNSTABLE AS YESTERDAY AND A FEW STRONG STORMS WITH SMALL HAIL ARE POSSIBLE. .LONG TERM... WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH DIGGING INTO THE PACIFIC NORTHWEST THIS MORNING. THIS SYSTEM IS EXPECTED TO SWIFTLY TRACK ACROSS THE NORTHERN HALF OF THE COUNTRY...REACHING THE UPPER MISSISSIPPI VALLEY BY LATE SATURDAY. THIS WILL SUBSTANTIALLY COMPRESS THE RIDGE OVER OUR AREA. SO ITS NO SURPRISE THAT CONVECTION WILL BE ON THE INCREASE THIS WEEKEND WITH LESS SUBSIDENCE. FOR NOW MAINTAINED PREVIOUS FCST POPS ON SATURDAY AT 30 TO 40 PCT BUT DID INCREASE SUNDAY TO 50 PCT COVERAGE WHICH MAY BE A LITTLE CONSERVATIVE. EARLIER NEXT WEEK...A WEAK FRONTAL BOUNDARY ASSOCIATED WITH THE PROGRESSIVE UPPER TROUGH WILL SAG TOWARDS THE CWA. IT WILL BE THE FOCUS FOR CONTINUED INCREASED DAILY CONVECTION. REGARDING TROPICAL STORM ERNESTO...THE STORM IS STILL UNDER THE INFLUENCE OF QUITE A BIT OF SHEAR AND IT STRUGGLING TO MAINTAIN CONVECTION AROUND THE CENTER OF CIRCULATION. THE SHEAR IS EXPECTED TO BE MUCH LESS IN ABOUT 2 DAYS. FROM THAT POINT THE STORM WILL BE IN MORE FAVORABLE CONDITIONS FOR STRENGTHENING OR EVEN JUST REDEVELOPMENT IF IT CONTINUES TO WEAKEN OVER THE NEXT COUPLE DAYS. THE STRENGTH OF THIS STORM WILL BE A MORE IMPORTANT FACTOR IN ITS LONG TERM TRACK. WEAKER SYSTEM WOULD TEND TO STAY FURTHER SOUTH ON A MORE WESTERLY TRACK. STRONGER SYSTEM WOULD LIKELY FEEL THE WEAKNESS IN THE RIDGE TO THE NORTH AND WANT TO STEER ON A MORE WNW TRACK. WHATEVER IT MAY BE...THE SYSTEM SHOULD BE NEAR THE WESTERN CARRIBEAN BY EARLY TO MID NEXT WEEK. MEFFER && .AVIATION... MAINLY VFR CONDITIONS WILL CONTINUE TO PREVAIL AT THE TAF SITES THROUGH 12Z SATURDAY. ISOLATED TO SCATTERED CONVECTION MAY IMPACT THE TERMINALS IN THE EASTERN HALF OF THE FORECAST AREA THIS AFTERNOON. 11 $$ |
| #531453 (Received by flhurricane at: 5:09 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 502 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHEN OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY INTO SUNDAY NIGHT WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON/EARLY SUNDAY EVENING...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE- FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION WITH A DAMAGING WIND THREAT. IF THE PRE-FRONTAL TROUGH REMAIN WEST OF THE AREA...CONVECTION WILL LIKELY BE MORE SCATTERED AND FOCUSED ALONG SEABREEZE BOUNDARIES...HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. IN THIS CASE...A FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW LEVEL WINDS/SHEAR. OVERRIDING THREAT WITH ANY STORMS WILL LIKELY BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE DUE TO STRONG LOW-LEVEL WINDS. MAIN THREAT THOUGH SHOULD BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO 2.25 TO 2.5 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS THIS MORNING HOWEVER...REDUCED VISIBILITIES IN BR ARE EXPECTED AT SOME OF THE TERMINALS THROUGH 11Z-12Z. THINKING ANY RESTRICTIONS WILL BE KEPT TO MVFR. AN ISOLATED LOCATION FALLING TO IFR HOWEVER CAN NOT BE RULED OUT. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. ...NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS AFTERNOON FOR TIMING OF SEABREEZE. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS MORNING FOR REDUCED VISIBILITY IN FOG. AMENDMENTS POSSIBLE LATE THIS AFTERNOON FOR TIMING OF SEABREEZE. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE THIS MORNING FOR REDUCED VISIBILITY IN FOG. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE LATE THIS MORNING OR EARLY THIS AFTERNOON FOR TIMING OF SEABREEZE. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...NV/DW |
| #531452 (Received by flhurricane at: 5:08 AM 03.Aug.2012) AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 402 AM CDT FRI AUG 3 2012 .SHORT TERM (TODAY THROUGH SATURDAY)...HIGH PRESSURE RIDGE SHIFTING TO THE WEST AND A BIT NORTH OVER THE NEXT 24-36 HOURS. THIS WILL ALLOW MOISTURE TO GRADUALLY INCREASE ACROSS THE AREA. EXPECT TODAY TO REMAIN NEARLY IDENTICAL TO CONDITIONS EXPERIENCED YESTERDAY. WENT WITH A PERSISTENCE MAX T FORECAST FROM YESTERDAY MAX T OBSERVATION...WITH JUST A FEW TWEAKS. ONLY OTHER DEVIATION FROM YESTERDAY IS THE POSSIBILITY FOR A FEW MORE CLOUDS THIS AFTERNOON WITH THE INCREASING MOISTURE. BY LATE TONIGHT PWAT VALUES ARE APPROACHING 1.5 INCH AND INCREASING FURTHER INTO SATURDAY. HAVE NOT CHANGED PRECIP FORECAST MUCH FROM PREVIOUS PACKAGE...WITH SLIGHT CHANCE POPS FOR MARINE AREAS LATE TOMORROW NIGHT...AND FOR MARINE PLUS COASTAL BEND FOR SATURDAY. && .LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...MOISTURE PROFILES IMPROVE SOME ON SUNDAY AND MONDAY...WITH PWATS AOA 2 INCHES OVER THE NORTHEAST SUNDAY AND COASTAL AREAS MONDAY. ISSUE HOWEVER IS HOW MUCH DOMINANCE UPPER HIGH WILL HAVE...AS GFS IS NOT MOVING UPPER HIGH AS FAR WEST AS PREVIOUSLY MODEL RUNS HAVE SHOWN. STILL...CAP BECOMES WEAKER WITH 700MB TEMPS AOB 10C BY MONDAY NEAR THE COAST. AS A RESULT...WILL NOT ONLY CONTINUE WITH LOW-END POPS BUT WILL INCREASE THEM FOR SUNDAY AND MONDAY OVER THE NORTHEAST TO LOW CHANCE (WOULD GO EVEN HIGHER IF RIDGE WAS NOT AS STRONG AS SHOWN. MOISTURE LINGERS ENOUGH FOR TUESDAY TO INCLUDE POPS AS HAVE HAD BEFORE. BIT DRIER AIR FOR WEDNESDAY AND MODELS DIFFER ON UPPER LOW/TUTT...WITH ECMWF HAVING THIS FEATURE WELL SOUTH IN MEXICO AND INLAND BY WEDNESDAY EVENING WHILE GFS BLOCKING SYSTEM WITH HIGH THEN MOVING IT INLAND BY THURSDAY (AND THAT COULD IMPACT DIRECTION OF ERNESTO IF THAT PANS OUT). FOR NOW...WILL KEEP THE LOW CHANCE POPS OVER THE EASTERN AREAS GIVEN POTENTIAL FOR TUTT BUT CONFIDENCE IN ISOLATED CONVECTION IS NOT AS GOOD AS YESTERDAY. OTHERWISE...DAYTIME TEMPERATURES CONTINUE TO REMAIN SLIGHTLY ABOVE NORMAL...WITH NEAR TO SLIGHT ABOVE NORMAL LOWS (MORE CLOSER TO NORMAL WHEN WINDS ARE LIGHT OR SOUTH-SOUTHWEST TOWARD MORNING. UNCERTAINTY DEFINITELY INCREASES AFTER THURSDAY AS ALL WILL DEPEND ON ERNESTO...WHERE IT IS AND HOW STRONG IT IS...AS WELL AS THE UPPER PATTERN WHICH WILL DICTATE WHERE ERNESTO WILL GO (IF IT GOES TOO FAR SOUTH AND INTO MOUNTAINS AS SOMETHING WEAKER MAY NOT BE MUCH OF AN ERNESTO...THAT IS WHAT ECMWF IS SAYING). HOWEVER...THAT IS BEYOND THIS FORECAST PERIOD BUT POTENTIAL CHALLENGING FORECAST ON THE HORIZON. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 97 79 96 79 97 / 10 10 20 10 20 VICTORIA 95 76 95 76 96 / 0 0 20 10 30 LAREDO 105 79 103 80 102 / 0 0 10 10 10 ALICE 102 77 100 77 100 / 0 0 10 10 20 ROCKPORT 90 80 93 81 93 / 10 10 20 10 30 COTULLA 106 75 102 76 103 / 0 0 10 10 10 KINGSVILLE 99 78 99 78 99 / 0 0 10 10 20 NAVY CORPUS 91 80 93 81 92 / 10 10 20 10 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531451 (Received by flhurricane at: 5:08 AM 03.Aug.2012) AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 400 AM CDT FRI AUG 3 2012 .DISCUSSION... SHORT TERM WX WILL BE STATUS QUO WITH STRONG H5 TROF CENTERED OVER N TX. THIS RIDGE IS FCST TO GRADUALLY SHIFT NWWD LATE IN THE WEEKEND AND INTO NEXT WEEK. INCREASED MOISTURE...COOLER H85 & H7 TEMPS...SEABREEZE AND IMPULSES ROTATING AROUND THE ERN PERIPHERY OF THE RIDGE SHOULD ALLOW FOR RAIN CHANCES TO BE RE-INTRODUCED INTO THE FCST. ATTM...MODELS PAINTING MONDAY AS HAVING THE MOST RAIN COVERAGE AND WILL TREND POPS ACCORDINGLY. STORM MOTION LOOKS TO BE ON THE SLOW SIDE (EVEN ON SUNDAY) SO THOSE THAT DO SEE THE PRECIP MIGHT SEE SOME LOCALIZED HIGHER AMOUNTS. FROM MIDWEEK ON...MEDIUM RANGE MODELS SHOW RIDGE CENTERED FROM THE ROCKIES INTO THE PLAINS....FAR ENOUGH AWAY TO ANTICIPATE SOME ISO SHRA/TSTM CHANCES EACH DAY. FLY IN THE OINTMENT OF COURSE IS WHAT TS ERNESTO DECIDES TO DO. VARIETY OF MODEL SOLNS OUT THERE...NONE OF WHICH CAN BE TAKEN TO THE BANK THIS FAR OUT - STILL A WEEK OUT IF IT WERE TO IMPACT US. 47 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 99 77 98 77 98 / 0 0 10 10 20 HOUSTON (IAH) 96 78 95 78 95 / 0 0 20 10 30 GALVESTON (GLS) 92 82 92 82 91 / 0 0 20 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531450 (Received by flhurricane at: 5:08 AM 03.Aug.2012) AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 454 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE COAST TODAY....AND WILL REMAIN OFF THE COAST THIS WEEKEND. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION EARLY MONDAY. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG HAS DEVELOPED EARLY THIS MORNING FROM THE BLUE RIDGE WEST AS SURFACE HIGH PRESSURE COVERS THE AREA. THE HIGH PRESSURE WILL SHIFT OFFSHORE DURING THE DAY AND AN INCREASING SOUTHERLY FLOW WILL KEEP A MOIST AIR MASS IN PLACE TODAY. 850MB TEMPERATURES AND DEW POINTS REMAIN ABOUT THE SAME TODAY AS YESTERDAY...AND WITH LITTLE CHANGE IN THE ATMOSPHERE HIGH TEMPERATURES WILL AGAIN BE IN THE MID 90/S. HEAT INDICES COULD EXCEED 100 DEGREES BETWEEN 2 PM AND 5 PM ESPECIALLY IN THE METRO AREAS BUT CONDITIONS SHOULD FALL SHORT OF A HEAT ADVISORY. THE COMPLEX OF STORMS CURRENTLY OVER INDIANA HAS SPREAD AN EXTENSIVE CLOUD SHIELD OVER OHIO THIS MORNING...AND SOME OF THESE ARE WORKING INTO PA/WV. THE WEAK SURFACE TROF NEAR ELKINS-WESTERN MD WILL LIFT NORTH AND WEST TODAY WHILE A WEAK UPPER TROF APPROACHES THE AREA LATER THIS AFTERNOON AND EVENING. SHOWERS AND THUNDERSTORMS WILL FIRE UP ALONG THE WESTERN MOUNTAINS BY EARLY AFTERNOON. AN ISOLATED STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE LATER IN THE AFTERNOON AS MOISTURE AND INSTABILITY IS RECIRCULATED. THE NAM KEEPS THE TROF OVER THE WVA PANHANDLE OVERNIGHT...CONTINUING THE RISK OF THUNDERSTORMS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... THIS WKND CWFA WL BE BTWN HIPRES RDG IN THE WRN ATLC AND A CDFNT/H5 VORTMAX CROSSING THE GRTLKS. THE UPA PTTN FEATURES WLY FLOW MAINLY CONFINED TO THE NRN CONUS...W/ BROAD HIPRES ACRS THE SRN STATES. THAT/LL LEAD TO TYPICAL HEAT AND HUMIDITY...WHICH WL CULMINATE IN LT DAY TSRA. NO BIG CHGS TO TEMP FCSTS...PER MOS CONSISTENCY. SAT ACTIVITY WL FEED OFF OF TRRN CIRCULATIONS...THTE MAX...AND MESOSCALE BNDRYS-- THE LATTER OF WHICH WL BE DFCLT TO PIN DWN FM THIS STANDPOINT. HV BUMPED UP POPS AREAWIDE...AND ATTEMPTED TO ADD A LTL PLACEMENT/TIMING DETAIL NONETHELESS. USED CLIMO A BIT IN TIMING...ORIGINATING TSRA IN MTNS BY ELY AFTN...EVOLVING INTO LEE TROF ELY EVNG...AND THEN PUSHING TWD DELMARVA AFDK. SUN WL BE INFLUENCED MORE BY THE APPCHG BNDRY/UPR TROF...WORKING ON AN UNSTBL AMS. NAM/GFS/ECMWF SEEM TO HV DECENT HANDLE ON TIMING...W/ A SUN NGT CFP. DYNAMICS AND LAPSE RATES PREFERRED N OF CWFA...WHICH IS WHERE THE HIER POPS WERE PLACED. THAT/S NOT TO DISCOUNT STRENGTH OF ACTIVITY W/IN CWFA...AS THERE/S MORE THAN ADEQUATE INSTBY/SHEAR...SPCLY FOR NRN CNTYS. MENTION OF SVR IN HWO WUD APPEAR JUSTIFIED. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PATTERN WL BE DOMINATED BY AN UPPER LVL RDG OVR THE ROCKY MTNS AND SLT TROFFING IN THE ERN U.S. BECAUSE OF THIS THE REALLY HIGH HEAT IS XPCTD TO BE HELD AT BAY THRU THE 1ST WK OF AUG. AFTR THE FNT MOVES THRU...AND THERE`S NO GUARANTEE AT THIS TIME OF THE YR THAT IT WL...UPR TROF SHOULD BE A CONTROLLER. AS MENTIONED ABV TEMPS SHOULD NOT GO MUCH ABV THE CLIMO NORMS...BUT ALMOST ALL SUMMER MDL TEMP FCSTS HV NOT BEEN WARM ENUF. THE FLIP IS THERE WAS ONE TIME THIS SUMMER (THAT I CAN RECALL) WHERE AFTR A FNT WENT THRU WE MOVED INTO A CAD ENVIRONMENT AND TEMPS ACTUALLY WERE BLO NORMS. FOR TIME BEING WL KEEP HIGHS IN U80S/LOWS 65-70. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS EXPECTED AT THE BWI...IAD AND DCA TERMINALS FOR THE NEXT 24 HOURS. MVFR 3-5SM BR LIKELY WEST OF THE BLUE RIDGE UNTIL 12Z...AND LOCALLY NEAR THE CHESAPEAKE BAY. SCT-BKN HIGH CLOUDS FL250 WILL SPREAD OVER THE AREA AS A FRONTAL SYSTEM WEAKENS TO THE NORTH. CUMULUS CLOUDS BASES FL050 POSSIBLE BY LATE AFTERNOON WITH LESS THAN A 20 PERCENT CHANCE OF A TS AT THE MAJOR TERMINALS THRU 22Z. SFC WINDS 18010KT. THIS CHANCE INCREASES TO 30 PERCENT BETWEEN 22Z AND 03Z...THEN DECREASES OVERNIGHT. FLGT RESTRICTIONS PSBL W/IN MAINLY DIURNAL TSRA SAT AND SUN. CVRG SUN MAY BE TIMED A LTL LATER DUE TO CFP. REDUCTIONS WUD BE BRIEF... POTENTIALLY DOWN TO IFR. ALSO MAY HV ELY MRNG VSBY RESTRICTIONS... MVFR MOST LKLY...THO IFR PSBL INVOF AREAS WHICH RECVD TSRA FM THE PRVS DAY. && .MARINE... SOUTHERLY CHANNELING COULD CAUSE SOME BREEZY AFTERNOON WINDS TODAY BUT EXPECTED TO REMAIN BELOW SCA CONDITIONS. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN THIS AFTERNOON. LOCALLY GUSTY WINDS AND LIGHTNING ARE POSSIBLE NEAR STORMS. SLY CHANNELING PSBL SAT EVNG...AND AGN LT SUN AHD OF CDFNT. POTL SCA FOR EACH OCCASION. ALSO WL HV TSRA DAILY TO CONTEND WITH...ANY OF WHICH MAY CONTAIN GUSTY WINDS. SMW/S PSBL. FROPA EITHER LT SUN OR ELY MON. && .TIDES/COASTAL FLOODING... WATER LEVELS ARE FORECAST TO RISE JUST ABOVE MINOR TIDAL FLOODING THRESHOLDS AT ANNAPOLIS...ALEXANDRIA AND THE SW WATERFRONT OF DC...AROUND THE ASTRONOMICAL HIGH TIDE LATER THIS MORNING. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...COASTAL FLOOD ADVISORY FROM 8 AM TO 11 AM EDT THIS MORNING FOR DCZ001. MD...COASTAL FLOOD ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ014. VA...COASTAL FLOOD ADVISORY FROM 8 AM TO 11 AM EDT THIS MORNING FOR VAZ054. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...HTS |
| #531449 (Received by flhurricane at: 4:59 AM 03.Aug.2012) AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 352 AM CDT FRI AUG 3 2012 .DISCUSSION... ONE MORE RELATIVELY QUIET WEATHER DAY...BEFORE RAIN CHANCE INCREASE FOR THIS WEEKEND. MID/UPPER LEVEL RIDGE IS EXPECTED TO SHIFT FURTHER WEST...ALLOWING SHORTWAVES ROTATING AROUND IT TO TRAVERSE OUR AREA...STARTING SATURDAY...AND CONTINUING TO AT LEAST MONDAY. BEYOND THAT...GOING WITH MORE TYPICAL LATE MORNING/AFTERNOON SHOWERS AND THUNDERSTORMS ASSOCIATED WITH SEA BREEZE. TEMPERATURE FORECASTS MAY BE MORE TRICKY DUE TO LOCATION AND TIMING OF SHOWERS AND THUNDERSTORMS THAT CAN CHANGE A MID 90S HIGH TO AN UPPER 80S READING...SO THERE IS SOME UNCERTAINTY IN THE MAX TEMPS THIS WEEK...BUT GOING WITH A NEAR NORMAL TO A DEGREE OR TWO ABOVE NORMAL. LOW TEMPS ALSO CAN BE INFLUENCED BY THE CONVECTION...BUT CLIMO LOWS IN THE MID AND UPPER 70S APPEAR REASONABLE. OF COURSE...ALSO MONITORING THE PROGRESS OF TROPICAL STORM ERNESTO...WHICH BEARS WATCHING FOR POSSIBLE GULF OF MEXICO ENTRANCE BY THE MIDDLE OF NEXT WEEK...IF IT CAN HOLD TOGETHER WITH AS MUCH SHEAR/DRY AIR IN ITS ENVIRONMENT TODAY. && .PRELIMINARY POINT TEMPS/POPS... KLCH 93 79 93 77 93 / 10 10 20 20 30 KBPT 93 78 93 77 93 / 10 10 20 20 30 KAEX 96 75 96 75 95 / 20 10 20 20 50 KLFT 94 78 91 76 91 / 20 10 30 20 50 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ |
| #531448 (Received by flhurricane at: 4:57 AM 03.Aug.2012) AFDBRO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 345 AM CDT FRI AUG 3 2012 .SHORT TERM /TODAY THROUGH SATURDAY/...LATEST MODEL PACKAGE SHOWS LITTLE CHANGE IN UPPER RIDGE STRUCTURE OVER THE NEXT 36 HOURS. THE CENTER OF THE DEEP LAYERED RIDGE TO REMAIN OVER NORTH CENTRAL TO NORTHWEST TEXAS MAINTAINING STRONG SUBSIDENT AIR ACROSS SOUTH TEXAS. PLENTY OF HEAT AND DRY AIR TO REMAIN IN PLACE TODAY AND SATURDAY WITH LITTLE TO NO RAIN EXPECTED. ANY ADDED MOISTURE ON SATURDAY IS NOT LIKELY TO KICK OFF ANYTHING MORE THEN ONE OR TWO SHOWERS OR THUNDERSTORMS. WARM AIR ALOFT TO MAINTAIN A CAP. INVERTED TROUGH THAT HAS BEEN TALKED ABOUT HAS BECOME STRETCHED OUT AND WEAKER AND STRONGER THEN USUAL SOUTH WINDS ARE NOT CONDUCIVE FOR AN ACTIVE SEA BREEZE. WITH THIS SAID...LOWERED SATURDAY POPS BELOW 20 PERCENT WITH KENEDY COUNTY THE BEST AREA TO SEE ISOLATED CONVECTION. TEMPERATURES TO REMAIN WELL ABOVE NORMAL WITH GOING FORECAST REMAINING ABOVE ALL GUIDANCE VALUES. SOUTHEAST WINDS TO INCREASE FRIDAY AND SATURDAY AFTERNOON WITH INLAND AREAS SEEING GUSTS BETWEEN 25 TO 30 MPH. .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...PATTERN SHIFT NEXT WEEK STILL EXPECTED TO BRING SOME CHANGES TO THE STAGNANT DOLDRUMS THAT HAVE BEEN THE PAST WEEK. THE UPPER RIDGE WILL SHIFT WESTWARD TO THE FOUR CORNERS REGION STARTING SUNDAY...TAKING THE CORE OF THE SUBSIDENCE WITH IT. AN INVERTED TROUGH WILL SHARPEN ACROSS THE SOUTHEASTERN US AND CHASE THE RIDGE WESTWARD ACROSS THE NORTHERN GULF. THIS WILL INTRODUCE DEEPER MOISTURE. THIS MOISTURE AND INSTABILITY FROM THE TROUGH WILL ALLOW THE SEABREEZE TO ACTIVATE EACH DAY AND PERSIST THROUGH THE WEEK. TEMPERATURES WILL REMAIN ABOVE NORMAL...BUT WILL BE HELD DOWN SLIGHTLY DUE TO DEEPER MOISTURE IN THE REGION. AS THE RIDGE MOVES WEST...THE HEAT LOW THAT HAS PERSISTED IN NORTH TEXAS WILL ALSO DEPART...ALLOWING WINDS TO SLACKEN FOR MOST OF THE WEEK. && .MARINE...NOW THROUGH SATURDAY...LOCAL PRESSURE GRADIENT WILL CONTINUE TO PRODUCE SMALL CRAFT EXERCISE CAUTION WINDS MAINLY OVER THE OPEN GULF DURING THE OVERNIGHT HOURS AND ACROSS THE LAGUNA DURING THE LATE MORNING AND AFTERNOON HOURS. A FEW AREAS NEAR PORT MANSFIELD COULD SEE INTERMITTENT SMALL CRAFT ADVISORY CONDITIONS BUT DURATION IS NOT LIKELY TO BE LONG ENOUGH TO WARRANT AN ADVISORY AT THIS TIME. SEAS CONSIST OF MAINLY WIND WAVES WHICH WILL FLUCTUATE 1 TO 3 FEET DURING THE DAY AND 3 TO 5 FEET OVERNIGHT. SATURDAY NIGHT THROUGH WEDNESDAY...LOW PRESSURE THAT HAS BEEN MEANDERING ACROSS NORTH TEXAS WILL WEAKEN AND SHIFT FURTHER WEST FOR THE EXTENDED PERIOD...ALLOWING WINDS TO SLACKEN TO AROUND 10 KNOTS. THIS WILL BRING LIGHTER SEAS 3 FEET OR LESS FOR THE FORECAST PERIOD. SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE EACH DAY DUE TO INSTABILITY ALOFT AND DEEPER MOISTURE. && .FIRE WEATHER...ENHANCED FIRE DANGER CONDITIONS WILL BE POSSIBLE MAINLY FROM 281 WESTWARD TODAY AND SATURDAY AFTERNOON. DRY AIR LOFT TO MIX DOWN TO THE SURFACE WITH DEW POINTS AND RELATIVE HUMIDITY VALUES TO FALL RAPIDLY THROUGH THE AFTERNOON. RH VALUES TO DROP BETWEEN 20 AND 30 PERCENT AND POSSIBLY BELOW 20 PERCENT IN ZAPATA, STARR AND JIM HOGG COUNTIES. 20FT WINDS ARE EXPECTED TO BE BELOW CRITICAL FIRE DANGER LEVELS...BUT CRITICAL GROWTH CONDITIONS ARE WARRANTED AS GUSTS RANGE FROM 20 TO 25 MPH LATE IN THE AFTERNOON AND VEGETATION REMAINS VERY DRY. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 95 81 93 81 / 10 10 10 20 BROWNSVILLE 97 80 94 79 / 10 10 10 10 HARLINGEN 101 78 96 78 / 10 10 10 10 MCALLEN 104 79 98 79 / 0 0 10 10 RIO GRANDE CITY 105 80 100 79 / 0 0 0 10 SOUTH PADRE ISLAND 87 81 90 82 / 10 10 10 20 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531444 (Received by flhurricane at: 4:41 AM 03.Aug.2012) AFDKEY AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS NATIONAL WEATHER SERVICE KEY WEST FL 432 AM EDT FRI AUG 3 2012 .DISCUSSION... CURRENTLY - A SURFACE ATLANTIC RIDGE STRETCHES ACROSS SOUTH FLORIDA...RESULTING IN VERY LIGHT WINDS ACROSS THE KEYS AREA. LAST EVENINGS SOUNDING INDICATED A MOIST AND TYPICALLY WARM BOUNDARY LAYER WITH A DRY STABILIZING LAYER AROUND 800 MB...PROVIDING SOME INHIBITION. AFTER A ROUND OF SHOWERS AROUND MIDNIGHT ALONG THE LOWER KEYS...SHOWER ACTIVITY HAS DIED OFF..LEAVING SKIES MOSTLY CLEAR TO PARTLY CLOUDY ACROSS THE FORECAST AREA. A WEAK INVERTED TROUGH IS ALIGNED ACROSS THE BAHAMAS...AND IS MIGRATING SLOWLY WEST NORTHWESTWARD. THIS FEATURE...ALONG WITH A TUTT CELL CENTERED OVER OUR AREA...IS RESULTING IN A SWATH OF SCATTERED SHOWERS AND THUNDERSTORMS OVER EASTERN CUBA AND THE BAHAMAS. FORECAST - RAIN CHANCES WILL REMAIN LOW AT LEAST THROUGH THE MORNING AND EARLY AFTERNOON HOURS. HOWEVER...AS THE WEAKENING INVERTED TROUGH APPROACHES OUR AREA...LOW LEVEL FLOW WILL BACK TO THE NORTHEAST...OPENING THE DOOR TO ISLAND CLOUD LINE CONVECTION AND ACTIVITY MOVING OFF OF SOUTH FLORIDA. GIVEN THIS POTENTIAL...WILL ADVERTISE MID CHANCE POPS FOR MAINLY LATE THIS AFTERNOON AND EVENING. THE WEAK TROUGH WILL MOVE THROUGH OUR AREA OVER THE WEEKEND...WHILE THE ASSOCIATED SWATH OF DEEPER MOISTURE GRADUALLY ERODES. HOWEVER...WEAK CYCLONIC TURNING THROUGH THE LOWER LEVELS AND INCREASE IN MOISTURE JUSTIFIES THE ALREADY ADVERTISED SLIGHTLY HIGHER THAN NORMAL POPS THROUGH THE WEEKEND. SURFACE WINDS WILL REMAIN GENERALLY LIGHT OUT OF THE EAST. A RELATIVELY BRIEF PERIOD OF MORE NORMAL POPS ARE EXPECTED FROM LATE SUNDAY INTO MONDAY AS A SWATH OF DRIER AIR MOVES IN FROM THE EAST WITH A SUBTLE SHORTWAVE RIDGE. LIGHT TO MODERATE EASTERLY FLOW WILL ESSENTIALLY LIMIT THE RAIN THREAT TO SHOWERS AND THUNDERSTORMS ALONG MARITIME BOUNDARIES. BY LATE MONDAY...WHATEVER TROPICAL STORM ERNESTO HAS EVOLVED INTO WILL BE MOVING IN TO THE WESTERN CARIBBEAN. GUIDANCE...SUGGESTS THAT LOW LEVEL MOISTURE WILL INCREASE...ALONG WITH A TIGHTENING OF THE LOW PRESSURE GRADIENT IN AN INCREASINGLY CYCLONIC FLOW WILL. UNCERTAINTY REMAINS LARGE...AS VIRTUALLY EVERY ELEMENT OF OUR FORECAST WILL BE HIGHLY DEPENDENT ON THE SPECIFIC TRACK...STRENGTH...AND INTENSITY OF ERNESTO. FOR THIS REASON...HAVE ONLY ADJUSTED POPS SLIGHTLY UPWARD TO A MID CHANCE WITH A SLIGHT INCREASE IN EASTERLY WINDS. THEREAFTER...LOWER LEVEL RIDGING WILL REASSERT ITSELF TO OUR NORTH...RESULTING IN LIGHT TO MODERATE EASTERLY FLOW...WITH NEAR NORMAL TEMPS AND POPS. && .MARINE... WINDS WILL REMAIN LIGHT OF THE EASTERN SIDE OF THE COMPASS THROUGH THE WEEKEND. WINDS ARE EXPECTED TO INCREASE OUT OF THE EAST EARLY NEXT WEEK...AS TROPICAL STORM ERNESTO MOVES INTO THE WESTERN CARIBBEAN. THERE WILL BE THE POTENTIAL THAT A CAUTION WILL BE REQUIRED FOR AT LEAST A PORTION OF KEYS WATERS. THEREAFTER...RIDGING WILL REMAIN NORTH OF OUR AREA...RESULTING IN MODERATE EASTERLY FLOW. && .AVIATION... VFR CONDITIONS WILL PREVAIL AT THE KEY WEST AND MARATHON ISLAND TERMINALS AT LEAST THROUGH THIS MORNING...WITH JUST BRIEF MVFR CIGS POSSIBLE. LONGER PERIODS OF MVFR CIGS AND EVEN SOME CONVECTIVE DEVELOPMENT WILL BE POSSIBLE THIS AFTERNOON WITH THE POTENTIAL DEVELOPMENT OF AN ISLAND CLOUD LINE...BUT CONFIDENCE IN THIS SCENARIO REMAINS LOW AT THIS POINT. A BETTER CHANCE FOR CONVECTION AT THE TERMINALS SHOULD OCCUR THIS EVENING...WHEN OUTFLOW BOUNDARIES FROM THE MAINLAND WILL LIKELY MIGRATE SOUTHWESTWARD INTO THE KEYS. HAVE INCLUDED VCSH IN THE TERMINALS STARTING AT 22-23Z. OUTSIDE OF ANY CONVECTION...SURFACE WINDS WILL REMAIN MOSTLY FROM THE EAST AROUND 5 KNOTS. && .PRELIMINARY POINT TEMPS/POPS... KEY WEST 88 81 88 81 / 40 40 40 40 MARATHON 93 81 92 80 / 40 40 40 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...NONE. GM...NONE. && $$ |
| #531443 (Received by flhurricane at: 4:36 AM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 429 AM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL INTO EARLY NEXT WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. A STATIONARY FRONT WILL STALL NORTH OF THE AREA MID TO LATE NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THROUGH SUNRISE...DEBRIS CLOUDINESS LEFT OVER FROM CONVECTION THURSDAY EVENING HAS GENERALLY DISSIPATED LEAVING MAINLY CLEAR SKIES. LINGERING WET GROUNDS WITHIN A LIGHT WIND REGIME SUGGESTS SOME PATCHY FOG WILL DEVELOP PRIOR TO SUNRISE. DO NOT ANTICIPATE DENSE FOG ATTM...BUT TRENDS WILL BE WATCHED CAREFULLY. THERE ARE INDICATIONS THAT SOME STRATUS COULD DEVELOP OVER THE CSRA AND FAR WESTERN AREAS OVER THE NEXT FEW HOURS. SHORT TERM GUIDANCE IS OFFERING MIXED SIGNALS ON EXACTLY HOW THIS WILL EVOLVE SO AGAIN WILL TAKE A SOMEWHAT CONSERVATIVE APPROACH WITH SKY COVER THROUGH SUNRISE. A FEW LOCATIONS HAVE DROPPED INTO THE UPPER 60S EARLY THIS MORNING...A BIT UNUSUAL FOR EARLY AUGUST. MORNING LOWS FROM THE UPPER 60S WELL INLAND TO THE UPPER 70S/NEAR 80 AT THE BEACHES LOOK ON TRACK. TODAY...THE REGION WILL REMAIN EMBEDDED WITHIN A BROAD WEAKNESS WITH A MID-LEVEL LOW PROGGED TO REMAIN ALONG THE NORTH CAROLINA COAST. SUNNY SKIES THIS MORNING WILL GIVE A QUICK BOOST TO TEMPERATURES DESPITE A SOMEWHAT COOL START WITH HIGHS STILL EXPECTED TO TOP OUT IN THE LOWER-MID 90S AWAY FROM THE COAST PRIOR TO THE ONSET OF CONVECTION. IT LOOKS TO BE ANOTHER BUSY AFTERNOON WITH LINGERING OUTFLOW BOUNDARIES AND THE SEA BREEZE BEING THE PRIMARY FOCI FOR CONVECTION TO INITIATE. RAP/NAM BUFR SOUNDINGS INDICATE THERE WILL BE PLENTY OF INSTABILITY THIS AFTERNOON WITH SBCAPES NEARING 3000 J/KG AND LIFTED INDICES AS LOW AS -8C. SHEAR PROFILES WILL REMAIN WEAK WITH 0-6KM BULK SHEAR ONLY MAXING OUT AROUND 15 KT DURING PEAK HEATING. WITH THE LACK OF ANY SIGNIFICANT UPPER SUPPORT ALOFT...AIRMASS TSTMS WILL BE PRIMARY DRIVEN BY MESOSCALE INTERACTIONS. MESOSCALE MODELS ARE SIMILAR IN CONCENTRATING TSTMS ACROSS INLAND AREAS BY MID-LATE AFTERNOON AHEAD OF THE SEA BREEZE WITH SOMEWHAT WEAK AGREEMENT WITH A CONVECTIVE MAXIMA COULD SETUP FROM LAKE MOULTRIE THROUGH WALTERBORO TO NEAR SPRINGFIELD. ITS A BIT TOO SOON TO SAY HOW THE MESOSCALE PATTERN WILL EVOLVE...SO WILL REMAIN SOMEWHAT CONSERVATIVE WITH A 20-40 PERCENT POP REGIME DURING THE AFTERNOON HOURS WITH THE HIGHEST GRIDDED POPS PLACED ROUGHLY ALONG A MONCKS CORNER-WALTERBORO-SPRINGFIELD LINE. SHORT TERM HIGHER POPS COULD BE NEEDED LATER TODAY ONCE MESOSCALE TRENDS ARE ESTABLISHED. DCAPES NEAR 1400 J/KG...DELTA EPT/S AROUND +34C...A WINDEX NEAR 65 KT AND A MODERATELY HIGH WET MICROBURST SEVERITY INDEX WILL CERTAINLY SUPPORT A RISK FOR DAMAGING WINDS. SEVERE HAIL IS ALSO A POSSIBILITY WITH ANOMALOUSLY LOW WBZ HEIGHTS IN PLACE FOR EARLY AUGUST. THE CONVECTIVE MODE WILL INITIALLY BE PULSE IN NATURE GIVEN THE WEAK SHEAR PROFILES THAT WILL BE IN PLACE...BUT MAY EVOLVE INTO MORE OF A MULTICELL SCENARIO SHOULD CONVECTIVE OUTFLOWS BEGIN TO INTERACT. PLAN TO HIGHLIGHT A POTENTIAL FOR SEVERE TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... ANY LINGERING CONVECTION WILL DISSIPATE BY LATE EVENING WITH THE LOSS OF INSOLATION AND CONVECTIVE OVERTURNING. CAN NOT COMPLETELY RULE OUT AN ISOLATED SHOWER/TSTM FIRING OVERNIGHT GIVEN THE NATURE OF THE AIRMASS IN PLACE...BUT PROBABILITIES FOR MEASURABLE RAINFALL WILL GENERALLY REMAIN LESS THAN 20 PERCENT. DEPENDING ON HOW QUICKLY DEBRIS CLOUDINESS WILL THIN...PATCHY FOG COULD DEVELOP WITHIN A LIGHT WIND REGIME. LOWS WILL RANGE FROM THE LOWER 70S INLAND TO THE UPPER 70S/NEAR 80 AT THE BEACHES AND DOWNTOWN CHARLESTON. THE SOUTHEAST STATES WILL REMAIN BETWEEN TWO UPPER LEVEL RIDGES THROUGH THE WEEKEND...WITH THE WESTERN RIDGE LOCATED OVER THE CENTRAL PLAINS AND THE EASTERN RIDGE CENTERED OVER THE ATLANTIC WATERS. AT THE SURFACE...ATLANTIC HIGH PRESSURE WILL EXTEND OVER THE MID ATLANTIC AND SOUTHEAST STATES...AS A WEAK INLAND TROUGH TAKES SHAPE BY MONDAY. THIS TYPICAL SUMMERTIME PATTERN WILL SUPPORT A GENERAL SOUTH- SOUTHEAST ONSHORE FLOW AND ALLOW THE DAILY INLAND PROGRESSION OF THE SEABREEZE. EXPECT PULSE TYPE SHOWERS AND THUNDERSTORMS TO INITIATE EACH AFTERNOON AND EVENING...DRIVEN MAINLY BY SEABREEZE CONVERGENCE...MESOSCALE BOUNDARY INTERACTIONS AND DIURNAL HEATING/INSTABILITY. WEAK SHORTWAVE ENERGY ON SATURDAY WILL MOVE OUT OF THE AREA BY SUNDAY AND MONDAY AS THE ATLANTIC RIDGE BUILDS WESTWARD...LEAVING LITTLE UPPER LEVEL SUPPORT THROUGH THE SHORT TERM PERIOD. AS A RESULT...ANY ISOLATED TO SCATTERED CONVECTION WILL DIMINISH IN COVERAGE WITHIN WANING HEATING/INSTABILITY BY SUNSET. HAVE MAINTAIN SHOWER/THUNDERSTORM CHANCES IN THE 20 TO 30 PERCENT RANGE EACH DAY. ALTHOUGH AN ISOLATED STRONG STORM IS POSSIBLE WITH THIS PULSE TYPE CONVECTION AND BOUNDARY INTERACTIONS...THE OVERALL SEVERE WEATHER THREAT WILL REMAIN LOW OVER THE PERIOD. HIGH TEMPERATURES WILL REACH THE LOWER 90S EACH AFTERNOON AWAY FROM THE LOCALLY COOLER COASTLINE...WHILE LOW TEMPERATURES ONLY FALL INTO THE LOW TO MID 70S. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... UPPER LEVEL RIDGING WILL BEGIN TO WEAKEN EARLY NEXT WEEK...AS A TROUGH ALOFT AND SEVERAL SHORTWAVES MOVE ACROSS THE NEW ENGLAND STATES. AN ASSOCIATED COLD FRONT WILL LIKELY STALL WELL TO THE NORTH OF THE FORECAST AREA BY THE MIDDLE OF NEXT WEEK. AT THE SURFACE...THE INLAND TROUGH COULD BECOME MORE PROMINENT BETWEEN SURFACE HIGH PRESSURE OVER THE CENTRAL UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. CONSIDERING THE INCREASED FORCING FROM THE STALLED FRONT TO THE NORTH...COMBINED WITH INFLUENCES FROM THE LEE TROUGH AND BOUNDARY/SEABREEZE INTERACTIONS...CONVECTIVE POTENTIAL COULD BE GREATER THROUGH THE EXTENDED PERIOD. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS...WITH HIGH TEMPERATURES IN THE LOW TO MID 90S DURING THE AFTERNOON FALLING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... MAINLY VFR. INTRODUCED PREVAILING MVFR VSBYS AT KSAV WHERE LIGHT WINDS...MAINLY CLEAR SKIES AND WET GROUNDS FROM EARLIER TSTMS COULD PROMOTE SOME GROUND FOG DEVELOPMENT. SCATTERED TSTMS ARE EXPECTED THIS AFTERNOON...MAINLY WEST OF THE TERMINALS SO WILL LEAVE ANY MENTION OUT OF THE 03/06Z TAFS. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER THAN 30 PERCENT CONFIDENCE LEVEL AT THIS TIME. && .MARINE... THERE ARE NO MARINE CONCERNS THROUGH TONIGHT. A BROAD SOUTHERLY FLOW REGIME WILL DOMINATE WITH WINDS GENERALLY 10-15 KT AND SEAS 2-3 FT. ATLANTIC HIGH PRESSURE WILL EXPAND OVER THE WATERS THIS WEEKEND...SUPPORTING CONDITIONS BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO EARLY NEXT WEEK. IN GENERAL...SOUTH WINDS BETWEEN 10-15 KT WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE...WITH HIGHEST WINDS EXPECTED NEAR THE INLAND MOVING SEABREEZE CIRCULATIONS AND EARLY NOCTURNAL SURGES. WINDS COULD BRIEFLY BECOME SOUTHEAST EACH AFTERNOON/EVENING AS THE SEABREEZE PUSHES INLAND. SEAS WILL REMAIN BETWEEN 1-3 FT...WITH SWELLS FROM THE SOUTH/SOUTHEAST. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531442 (Received by flhurricane at: 4:26 AM 03.Aug.2012) AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 359 AM EDT FRI AUG 3 2012 THE FLA PENINSULA WILL REMAIN IN A COL AREA BETWEEN A HIGH PRESSURE CELL OVER THE SOUTHERN GREAT PLAINS WITH A CELL WELL OUT INTO THE MID ATLC E OF THE CENTRAL U.S. E COAST BUT WITH THE RIDGE EXTENDING SW OVER THE BAHAMAS TOWARD THE CENTRAL CARIB. THE EASTERLY FLOW ABOUT THE BASE OF THE ATLC CELL THOUGH DIRECTS THE FOCUS OF THIS FORECAST TOWARD 2 TROPICAL FEATURES WITH THE FORMER AFFECTING THE NEAR TERM AND THE LATTER POSSIBLY IN THE EXTENDED PERIOD. SHORT TERM...TODAY THROUGH SUNDAY...THE LATEST 850MB STREAMLINE ANALYSIS INDICATES THE TROPICAL WAVE EXTENDING SW FROM THE N BAHAMAS ACROSS W CENTRAL CUBA AND INTO THE W CARIB. SATL LOOPS...IR/WATER VAPOR DEPICT AMPLE MOISTURE/CLOUD COVER TO THE E OF THE WAVE AXIS AND LONG RANGE RADAR DETECTS SHOWERS...SOME THUNDERSTORMS OVER THE ATLC WATERS W OF THE BAHAMAS. MODELS PRETTY MUCH IN AGREEMENT IN MOVING THIS WAVE SLOWLY W TOWARD S FLA AND ONTO THE E COAST LATER TONIGHT AND INTO THE W GULF OF MEX SUNDAY AFTERNOON. SO...WITH A SLOWLY DEEPENING EASTERLY MOIST FLOW...THE CHANCES OF RAIN FOR S FLA GRADUALLY INCREASE. THE ECMWF/GFS BOTH FORECAST AN UPPER LEVEL LOW DEVELOPING IN THE COL TO THE W OF S FLA SATURDAY. THIS MAY ENHANCE TO CHANCE OF RAIN AS UPPER LEVEL WIND DIVERGENCE WILL CREATE INCREASE INSTABILITY. CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS TODAY WILL BE DRIVEN BY LOW LEVEL CONVERGENCE DUE TO SEA BREEZE INTERACTION WITH A LEAN TOWARD ACTIVITY BEING CONCENTRATED IN THE INTERIOR AND TOWARD THE LAKE OKEE REGION. INCREASED CHANCE OF RAIN E COAST TONIGHT AND OVER THE WEEKEND ALL ZONES BUT WITH THE AFTERNOON AND EVENING CONCENTRATION OF ACTIVITY INTERIOR AND W AS A DEEPER EASTERLY WIND FLOW DEVELOPS. DURING THIS TIME...TROPICAL STORM ERNESTO WILL MOVE STEADILY WESTWARD THROUGH THE CARIB AND BY SATURDAY...PER NHC GUIDANCE...WILL BE S OF THE GREATER ANTILLES AND BECOME A MINIMAL HURRICANE BY LATE SATURDAY NIGHT( SEE LATEST NHC GUIDANCE). .LONG TERM...MONDAY THROUGH THURSDAY...THE CHANCE OF RAIN TAPERS DOWNWARD FROM MIDWEEK ON AS THE ATLC HIGH CENTER MOVES WESTWARD PULLING SOME DRIER AIR OVER S FLA. A DEEP EASTERLY WIND FLOW DICTATES THAT THE HIGHER POPS WILL BE IN THE W INTERIOR AND W COAST. FORECASTED HURRICANE ERNESTO APPROACHES THE YUCATAN PENINSULA BY MID WEEK. AS ERNESTO TRACKS WESTWARD...AT THIS TIME...THE ONLY EFFECT TO S FLA WILL BE AN INCREASE IN THE LOW LEVEL EASTERLY WINDS FROM MIDWEEK ON. BUT KEEP AWARE OF NHC FORECASTS OF THE DEVELOPMENT AND FORECASTED MOVEMENT OF THIS STORM. && .MARINE...AT THIS TIME...EASTERLY WINDS WILL BE BELOW 15 KNOTS WITH SEAS 3 FEET OR LESS TODAY AND THROUGH THE WEEKEND. WINDS AND SEAS WILL BEGIN TO INCREASE EARLY NEXT WEEK BUT AT THIS TIME NO HIGHLIGHTS ARE EXPECTED. && .FIRE WEATHER...NO CONCERNS AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 91 79 89 77 / 30 30 50 40 FORT LAUDERDALE 91 79 89 79 / 30 30 50 40 MIAMI 91 78 90 79 / 30 30 50 40 NAPLES 90 77 91 77 / 30 20 50 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...15/JR |
| #531441 (Received by flhurricane at: 4:26 AM 03.Aug.2012) AFDJAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 422 AM EDT FRI AUG 3 2012 .CURRENTLY... EARLY MORNING SURFACE ANALYSIS DEPICTS A RELATIVELY WEAK PRESSURE PATTERN AND LIGHT WINDS OVER OUR REGION. A WEAK TROPICAL WAVE IS MOVING WEST-NORTHWESTWARD ACROSS THE BAHAMAS...WITH RIDGING CENTERED OVER THE CENTRAL ATLANTIC OCEAN. WEAK TROUGHING ALOFT REMAINS OVER OUR REGION...WITH A COUPLE OF EMBEDDED SHORTWAVES EXTENDING FROM THE CAROLINA COAST SOUTHWARD TO NEAR CAPE CANAVERAL. OTHERWISE...THE LARGE AND PERSISTENT RIDGE CENTERED OVER THE SOUTHERN PLAINS STATES IS BEGINNING TO FLATTEN AND EXPAND EASTWARD. MID AND HIGH ALTITUDE CLOUDINESS ASSOCIATED WITH THE SHORTWAVE ENERGY IS GRADUALLY DEPARTING NORTHEAST FLORIDA...WITH FAIR SKIES THROUGHOUT SOUTHEAST GEORGIA. LOCAL RADARS DETECT ISOLATED SHOWERS DEVELOPING OVER COASTAL PORTIONS OF THE FLORIDA BIG BEND...AND THIS ACTIVITY IS DRIFTING NORTHWARD. TEMPERATURES RANGE FROM 70 TO 75 INLAND...TO THE UPPER 70S ALONG THE IMMEDIATE COAST. ON THE COASTAL WATERS...MAINLY SOUTHERLY WINDS OF 5 TO 10 KNOTS WERE REPORTED AT THE NEARSHORE CMANS AND THE OFFSHORE BUOYS. .SHORT TERM (TODAY THROUGH SUNDAY NIGHT)... WEAK TROUGHING WILL PERSIST TODAY. MODEL SOUNDINGS DEPICT RATHER COOL TEMPERATURES ALOFT (-7/-8 DEGREES CELSIUS AT 500 MILLIBARS)...AND THIS COMBINED WITH INCREASING MOISTURE DURING THE AFTERNOON AND A RATHER UNSTABLE PROFILE WILL LEAD TO SCATTERED THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON HOURS THROUGHOUT OUR REGION. ACTIVITY WILL FOCUS ALONG MESOSCALE BOUNDARIES SUCH AS THE GULF AND EAST COAST SEABREEZES AND ASSOCIATED OUTFLOWS...AND THESE BOUNDARIES WILL LIKELY COLLIDE LATE THIS AFTERNOON OR EARLY THIS EVENING OVER INTERIOR LOCATIONS. WE EXPECT ANOTHER SEASONABLY HOT DAY BEFORE THUNDERSTORM ACTIVITY ERUPTS...AND WITH PERSISTENCE IN MIND...WILL FORECAST HIGH TEMPERATURES SLIGHTLY ABOVE GUIDANCE FOR INTERIOR LOCATIONS (MID 90S)...WITH HEAT INDICES TOPPING OUT IN THE 100-106 DEGREE RANGE. THE EAST COAST SEA BREEZE SHOULD MOVE INLAND EARLIER THIS AFTERNOON...AND THUS WE EXPECT HIGHS CLOSER TO 90 ALONG THE BEACHES. A WEAK TROPICAL WAVE WILL MOVE SLOWLY WESTWARD ACROSS THE FLORIDA PENINSULA THIS WEEKEND. MOISTURE VALUES WILL GRADUALLY INCREASE FROM SOUTHEAST TO NORTHWEST AS THE WEEKEND PROGRESSES. AS ATLANTIC SURFACE RIDGING BUILDS IN BEHIND THE WAVE AXIS...OUR LOW AND MID LEVEL FLOW WILL GRADUALLY INCREASE OUT OF THE SOUTHEAST. ISOLATED TO SCATTERED MORNING COASTAL CONVECTION IS EXPECTED...ESPECIALLY ON SUNDAY AS THE SOUTHEAST FLOW STRENGTHENS BEHIND THE WAVE AXIS. ONSHORE WINDS WILL QUICKLY PUSH THE EAST COAST SEA BREEZE INLAND ON SATURDAY AND SUNDAY...FOCUSING A HIGHER COVERAGE OF SCATTERED TO NUMEROUS AFTERNOON AND EARLY EVENING CONVECTION FOR LOCATIONS WEST OF THE ST. JOHNS RIVER AND FROM THE OKEFENOKEE SWAMP WEST AND NORTHWESTWARD. EXPECT MORE CLOUDINESS TO DEVELOP BY THE EARLY AFTERNOON HOURS THIS WEEKEND...WHICH WILL RESULT IN HIGH TEMPERATURES CLOSER TO EARLY AUGUST CLIMATOLOGY (LOWER 90S). LOWS AND HUMIDITY VALUES WILL REMAIN NEAR CLIMO THROUGHOUT THE SHORT TERM PERIOD. .LONG TERM (MONDAY THROUGH THURSDAY)... ATLANTIC RIDGING WILL EXPAND WESTWARD FOLLOWING THE PASSAGE OF THE TROPICAL WAVE. MOISTURE LEVELS WILL REMAIN SOMEWHAT ELEVATED THROUGH TUESDAY. THE AXIS OF ATLANTIC SURFACE RIDGING WILL BE POSITIONED ACROSS OUR REGION...AND WEAKENING SOUTHEAST TO SOUTHERLY STEERING FLOW SHOULD PROMOTE ACTIVE SEA BREEZES. THIS WEATHER PATTERN WILL FEATURE THE TYPICAL DIURNAL DEVELOPMENT OF SCATTERED CONVECTION...WITH ACTIVITY FOCUSED OVER INTERIOR LOCATIONS AND THEN DECREASING AREA-WIDE TOWARDS MIDNIGHT EACH EVENING. RIDGING ALOFT WILL THEN BIFURCATE BY MIDWEEK...WITH WEAK TROUGHING BECOMING ESTABLISHED OVER THE SOUTHEASTERN STATES AS RIDGING OVER THE FOUR CORNERS REGION AMPLIFIES. A SLIGHTLY HIGHER COVERAGE OF CONVECTION CLOSER TO THE TROUGH OVER SOUTHEAST GEORGIA IS POSSIBLE LATER NEXT WEEK. FOR NOW...WE WILL KEEP SCATTERED POPS IN THE FORECAST GRIDS AREA-WIDE AND AWAIT MODEL CONSISTENCY BEFORE MAKING SIGNIFICANT ADJUSTMENTS. ANY ENHANCED MOISTURE ASSOCIATED WITH ERNESTO SHOULD REMAIN WELL TO THE SOUTH OF OUR AREA. EXPECT TEMPERATURES AND HUMIDITY VALUES TO REMAIN NEAR EARLY AUGUST CLIMATOLOGY NEXT WEEK. && .AVIATION... OCNL MVFR VSBY AT GNV AND VQQ TIL 12Z. OTHERWISE VFR. SCATTERED LATE AFTERNOON STORMS ARE EXPECTED AS THE SEA BREEZES MOVE INLAND. HAVE VCTS AT ALL NE FL TERMINALS AFT 20Z-21Z. && .MARINE... A RIDGE OF HIGH PRESSURE OVER THE REGION WILL LIFT TO THE NORTH OF THE WATERS THIS WEEKEND. S/SW WINDS THIS MORNING BECOMING SE ALONG THE COAST THIS AFTERNOON. WINDS WILL GENERALLY BE EAST TO SOUTHEAST OVER THE WEEKEND INTO NEXT WEEK WITH THE RIDGE NORTH OF THE AREA. NO HEADLINES EXPECTED. ISOLATED SHOWERS AND STORMS TODAY BECOMING SCATTERED OVER THE WEEKEND AND NEXT WEEK FROM A TROPICAL WAVE. RIP CURRENTS: LOW RISK THROUGH SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 95 74 93 72 / 40 20 40 20 SSI 89 78 87 77 / 20 20 40 20 JAX 95 75 92 74 / 30 30 40 20 SGJ 91 75 89 76 / 20 20 40 20 GNV 95 72 93 71 / 40 30 50 30 OCF 94 72 92 73 / 40 20 50 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ |
| #531431 (Received by flhurricane at: 4:24 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 400 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHEN OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY/SUNDAY EVENING WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE-FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION. OTHERWISE...SCATTERED CONVECTION WILL LIKELY BE FOCUSED ALONG SEABREEZE BOUNDARIES OR OFF HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. A FEW STRONG TO SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW-LEVEL WINDS/SHEAR. MAIN THREAT WITH ANY STORMS WILL BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE WITH STRONG LOW-LEVEL WINDS. MAIN THREAT WILL BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO OVER 2 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS OVERNIGHT HOWEVER...REDUCED VISIBILITIES IN BR EXPECTED FOR SOME TERMINALS AFTER MAINLY 07Z. LOW CONFIDENCE REGARDING HOW LOW THEY GET REDUCED PARTICULARLY AT KHPN AND KGON. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ |
| #531439 (Received by flhurricane at: 4:24 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM THURSDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA...POSSIBLY ACCOMPANIED BY THUNDER...OVER LAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND MID LEVEL DYNAMICS WILL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. COULD BE ONE OF THOSE DAYS WHERE...CONVECTION BREAKS OUT ALONG THE IMMEDIATE COAST THROUGH MID TO LATE MORNING. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...LOW PROBABILITIES OF SHRA/TSRA OVERNIGHT. VFR CONDITIONS ARE LIKELY TO GIVE WAY TO MVFR VSBYS BY 08Z AS SKIES CLEAR. CONFIDENCE OF THE TIMING AND DURATION OF IFR LOW BUT GENERALLY FROM 09-11Z. VFR EXPECTED 1-2 HRS AFTER SUNRISE. CONVECTION SHOULD DEVELOP AFT 16Z BUT NO ORGANIZED CONVECTION EXPECTED DUE TO NUMEROUS OUTFLOW BOUNDARY INTERACTIONS. WILL LEAVE MENTION OF CONVECTION FOR LATER TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR...FOLLOWED BY CHANCE FOR SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WINDS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531437 (Received by flhurricane at: 4:23 AM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS UPR-LVL LO PRES OVER EASTERN CANADA WITH AN ASSOCIATED TROF WELL EAST OF THE MID ATLANTIC. WEAK CYCLONIC FLOW ALOFT AND EMBEDDED PERTURBATIONS WILL LEAD TO ANOTHER CHC OF SHWRS AND TSTMS THIS AFTN AND EVNG AS THE ATM REMAINS MOIST FROM THE SFC TO 700 MB. ALTHO SHEAR IS VERY WEAK AND FORCING IS LACKING...SOME STORMS MAY BE STRONG AS LO-LVL LAPSE RATES WILL BE VERY STEEP AND LIFTED INDICES ARE PROGGED B/T -4 AND -7 PER LATEST NAM GUIDANCE. TEMPS WILL MAX OUT IN THE LOW TO MID 90S...WITH HEAT INDICES PEAKING IN THE UPR 90S. ANY CONVECTION WILL DISSIPATE TNGT FOLLOWING THE LOSS OF DAYTIME HEATING. LOW TEMPS OVRNGT MAINLY IN THE LOW 70S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 3-5KT OVERNIGHT. ADDITIONALLY...CURRENT DEWPOINT DEPRESSIONS ARE AROUND 5-8F AT THE TAF SITES. HENCE IFR CONDITIONS ARE NOT EXPECTED GIVEN THE COMBINATION OF A LIGHT WIND AND THE LATEST DEWPOINT DEPRESSIONS. THERE STILL COULD BE A PERIOD OF MVFR CONDITIONS AROUND SUNRISE MOST LIKELY OCCURRING AT RIC/SBY/ECG. OTHERWISE...THE SKY SHOULD BE MOSTLY CLEAR/MOSTLY SUNNY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531429 (Received by flhurricane at: 4:21 AM 03.Aug.2012) AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 357 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE COAST TODAY....AND WILL REMAIN OFF THE COAST THIS WEEKEND. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION EARLY MONDAY. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG HAS DEVELOPED EARLY THIS MORNING FROM THE BLUE RIDGE WEST AS SURFACE HIGH PRESSURE COVERS THE AREA. THE HIGH PRESSURE WILL SHIFT OFFSHORE DURING THE DAY AND AN INCREASING SOUTHERLY FLOW WILL KEEP A MOIST AIR MASS IN PLACE TODAY. 850MB TEMPERATURES AND DEW POINTS REMAIN ABOUT THE SAME TODAY AS YESTERDAY...AND WITH LITTLE CHANGE IN THE ATMOSPHERE HIGH TEMPERATURES WILL AGAIN BE IN THE MID 90/S. HEAT INDICES COULD EXCEED 100 DEGREES BETWEEN 2 PM AND 5 PM ESPECIALLY IN THE METRO AREAS BUT CONDITIONS SHOULD FALL SHORT OF A HEAT ADVISORY. THE COMPLEX OF STORMS CURRENTLY OVER INDIANA HAS SPREAD AN EXTENSIVE CLOUD SHIELD OVER OHIO THIS MORNING...AND SOME OF THESE ARE WORKING INTO PA/WV. THE WEAK SURFACE TROF NEAR ELKINS-WESTERN MD WILL LIFT NORTH AND WEST TODAY WHILE A WEAK UPPER TROF APPROACHES THE AREA LATER THIS AFTERNOON AND EVENING. SHOWERS AND THUNDERSTORMS WILL FIRE UP ALONG THE WESTERN MOUNTAINS BY EARLY AFTERNOON. AN ISOLATED STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE LATER IN THE AFTERNOON AS MOISTURE AND INSTABILITY IS RECIRCULATED. THE NAM KEEPS THE TROF OVER THE WVA PANHANDLE OVERNIGHT...CONTINUING THE RISK OF THUNDERSTORMS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... THIS WKND CWFA WL BE BTWN HIPRES RDG IN THE WRN ATLC AND A CDFNT/H5 VORTMAX CROSSING THE GRTLKS. THE UPA PTTN FEATURES WLY FLOW MAINLY CONFINED TO THE NRN CONUS...W/ BROAD HIPRES ACRS THE SRN STATES. THAT/LL LEAD TO TYPICAL HEAT AND HUMIDITY...WHICH WL CULMINATE IN LT DAY TSRA. NO BIG CHGS TO TEMP FCSTS...PER MOS CONSISTENCY. SAT ACTIVITY WL FEED OFF OF TRRN CIRCULATIONS...THTE MAX...AND MESOSCALE BNDRYS-- THE LATTER OF WHICH WL BE DFCLT TO PIN DWN FM THIS STANDPOINT. HV BUMPED UP POPS AREAWIDE...AND ATTEMPTED TO ADD A LTL PLACEMENT/TIMING DETAIL NONETHELESS. USED CLIMO A BIT IN TIMING...ORIGINATING TSRA IN MTNS BY ELY AFTN...EVOLVING INTO LEE TROF ELY EVNG...AND THEN PUSHING TWD DELMARVA AFDK. SUN WL BE INFLUENCED MORE BY THE APPCHG BNDRY/UPR TROF...WORKING ON AN UNSTBL AMS. NAM/GFS/ECMWF SEEM TO HV DECENT HANDLE ON TIMING...W/ A SUN NGT CFP. DYNAMICS AND LAPSE RATES PREFERRED N OF CWFA...WHICH IS WHERE THE HIER POPS WERE PLACED. THAT/S NOT TO DISCOUNT STRENGTH OF ACTIVITY W/IN CWFA...AS THERE/S MORE THAN ADEQUATE INSTBY/SHEAR...SPCLY FOR NRN CNTYS. MENTION OF SVR IN HWO WUD APPEAR JUSTIFIED. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PATTERN WL BE DOMINATED BY AN UPPER LVL RDG OVR THE ROCKY MTNS AND SLT TROFFING IN THE ERN U.S. BECAUSE OF THIS THE REALLY HIGH HEAT IS XPCTD TO BE HELD AT BAY THRU THE 1ST WK OF AUG. AFTR THE FNT MOVES THRU...AND THERE`S NO GUARANTEE AT THIS TIME OF THE YR THAT IT WL...UPR TROF SHOULD BE A CONTROLLER. AS MENTIONED ABV TEMPS SHOULD NOT GO MUCH ABV THE CLIMO NORMS...BUT ALMOST ALL SUMMER MDL TEMP FCSTS HV NOT BEEN WARM ENUF. THE FLIP IS THERE WAS ONE TIME THIS SUMMER (THAT I CAN RECALL) WHERE AFTR A FNT WENT THRU WE MOVED INTO A CAD ENVIRONMENT AND TEMPS ACTUALLY WERE BLO NORMS. FOR TIME BEING WL KEEP HIGHS IN U80S/LOWS 65-70. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS EXPECTED AT THE BWI...IAD AND DCA TERMINALS FOR THE NEXT 24 HOURS. MVFR 3-5SM BR LIKELY WEST OF THE BLUE RIDGE UNTIL 12Z...AND LOCALLY NEAR THE CHESAPEAKE BAY. SCT-BKN HIGH CLOUDS FL250 WILL SPREAD OVER THE AREA AS A FRONTAL SYSTEM WEAKENS TO THE NORTH. CUMULUS CLOUDS BASES FL050 POSSIBLE BY LATE AFTERNOON WITH LESS THAN A 20 PERCENT CHANCE OF A TS AT THE MAJOR TERMINALS THRU 22Z. SFC WINDS 18010KT. THIS CHANCE INCREASES TO 30 PERCENT BETWEEN 22Z AND 03Z...THEN DECREASES OVERNIGHT. FLGT RESTRICTIONS PSBL W/IN MAINLY DIURNAL TSRA SAT AND SUN. CVRG SUN MAY BE TIMED A LTL LATER DUE TO CFP. REDUCTIONS WUD BE BRIEF... POTENTIALLY DOWN TO IFR. ALSO MAY HV ELY MRNG VSBY RESTRICTIONS... MVFR MOST LKLY...THO IFR PSBL INVOF AREAS WHICH RECVD TSRA FM THE PRVS DAY. && .MARINE... SOUTHERLY CHANNELING COULD CAUSE SOME BREEZY AFTERNOON WINDS TODAY BUT EXPECTED TO REMAIN BELOW SCA CONDITIONS. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN THIS AFTERNOON. LOCALLY GUSTY WINDS AND LIGHTNING ARE POSSIBLE NEAR STORMS. SLY CHANNELING PSBL SAT EVNG...AND AGN LT SUN AHD OF CDFNT. POTL SCA FOR EACH OCCASION. ALSO WL HV TSRA DAILY TO CONTEND WITH...ANY OF WHICH MAY CONTAIN GUSTY WINDS. SMW/S PSBL. FROPA EITHER LT SUN OR ELY MON. && .TIDES/COASTAL FLOODING... WATER LEVELS ARE FORECAST TO BE CLOSE...BUT JUST BELOW MINOR TIDAL FLOODING THRESHOLDS. WILL HAVE TO WATCH SENSITIVE LOCATIONS SUCH AS ANNAPOLIS FOR POSSIBLE MINOR TIDAL FLOODING LATER THIS MORNING. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...HTS |
| #531434 (Received by flhurricane at: 4:21 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM THURSDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA...POSSIBLY ACCOMPANIED BY THUNDER...OVER LAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND MID LEVEL DYNAMICS WILL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. COULD BE ONE OF THOSE DAYS WHERE...CONVECTION BREAKS OUT ALONG THE IMMEDIATE COAST THROUGH MID TO LATE MORNING. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...LOW PROBABILITIES OF SHRA/TSRA OVERNIGHT. VFR CONDITIONS ARE LIKELY TO GIVE WAY TO MVFR VSBYS BY 08Z AS SKIES CLEAR. CONFIDENCE OF THE TIMING AND DURATION OF IFR LOW BUT GENERALLY FROM 09-11Z. VFR EXPECTED 1-2 HRS AFTER SUNRISE. CONVECTION SHOULD DEVELOP AFT 16Z BUT NO ORGANIZED CONVECTION EXPECTED DUE TO NUMEROUS OUTFLOW BOUNDARY INTERACTIONS. WILL LEAVE MENTION OF CONVECTION FOR LATER TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR...FOLLOWED BY CHANCE FOR SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WINDS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531433 (Received by flhurricane at: 4:21 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 400 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHEN OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY/SUNDAY EVENING WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE-FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION. OTHERWISE...SCATTERED CONVECTION WILL LIKELY BE FOCUSED ALONG SEABREEZE BOUNDARIES OR OFF HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. A FEW STRONG TO SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW-LEVEL WINDS/SHEAR. MAIN THREAT WITH ANY STORMS WILL BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE WITH STRONG LOW-LEVEL WINDS. MAIN THREAT WILL BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO OVER 2 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS OVERNIGHT HOWEVER...REDUCED VISIBILITIES IN BR EXPECTED FOR SOME TERMINALS AFTER MAINLY 07Z. LOW CONFIDENCE REGARDING HOW LOW THEY GET REDUCED PARTICULARLY AT KHPN AND KGON. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ |
| #531440 (Received by flhurricane at: 4:21 AM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS UPR-LVL LO PRES OVER EASTERN CANADA WITH AN ASSOCIATED TROF WELL EAST OF THE MID ATLANTIC. WEAK CYCLONIC FLOW ALOFT AND EMBEDDED PERTURBATIONS WILL LEAD TO ANOTHER CHC OF SHWRS AND TSTMS THIS AFTN AND EVNG AS THE ATM REMAINS MOIST FROM THE SFC TO 700 MB. ALTHO SHEAR IS VERY WEAK AND FORCING IS LACKING...SOME STORMS MAY BE STRONG AS LO-LVL LAPSE RATES WILL BE VERY STEEP AND LIFTED INDICES ARE PROGGED B/T -4 AND -7 PER LATEST NAM GUIDANCE. TEMPS WILL MAX OUT IN THE LOW TO MID 90S...WITH HEAT INDICES PEAKING IN THE UPR 90S. ANY CONVECTION WILL DISSIPATE TNGT FOLLOWING THE LOSS OF DAYTIME HEATING. LOW TEMPS OVRNGT MAINLY IN THE LOW 70S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 3-5KT OVERNIGHT. ADDITIONALLY...CURRENT DEWPOINT DEPRESSIONS ARE AROUND 5-8F AT THE TAF SITES. HENCE IFR CONDITIONS ARE NOT EXPECTED GIVEN THE COMBINATION OF A LIGHT WIND AND THE LATEST DEWPOINT DEPRESSIONS. THERE STILL COULD BE A PERIOD OF MVFR CONDITIONS AROUND SUNRISE MOST LIKELY OCCURRING AT RIC/SBY/ECG. OTHERWISE...THE SKY SHOULD BE MOSTLY CLEAR/MOSTLY SUNNY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531427 (Received by flhurricane at: 4:18 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 400 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHEN OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY/SUNDAY EVENING WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE-FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION. OTHERWISE...SCATTERED CONVECTION WILL LIKELY BE FOCUSED ALONG SEABREEZE BOUNDARIES OR OFF HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. A FEW STRONG TO SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW-LEVEL WINDS/SHEAR. MAIN THREAT WITH ANY STORMS WILL BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE WITH STRONG LOW-LEVEL WINDS. MAIN THREAT WILL BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO OVER 2 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS OVERNIGHT HOWEVER...REDUCED VISIBILITIES IN BR EXPECTED FOR SOME TERMINALS AFTER MAINLY 07Z. LOW CONFIDENCE REGARDING HOW LOW THEY GET REDUCED PARTICULARLY AT KHPN AND KGON. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ |
| #531426 (Received by flhurricane at: 4:18 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM THURSDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA...POSSIBLY ACCOMPANIED BY THUNDER...OVER LAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND MID LEVEL DYNAMICS WILL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. COULD BE ONE OF THOSE DAYS WHERE...CONVECTION BREAKS OUT ALONG THE IMMEDIATE COAST THROUGH MID TO LATE MORNING. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...LOW PROBABILITIES OF SHRA/TSRA OVERNIGHT. VFR CONDITIONS ARE LIKELY TO GIVE WAY TO MVFR VSBYS BY 08Z AS SKIES CLEAR. CONFIDENCE OF THE TIMING AND DURATION OF IFR LOW BUT GENERALLY FROM 09-11Z. VFR EXPECTED 1-2 HRS AFTER SUNRISE. CONVECTION SHOULD DEVELOP AFT 16Z BUT NO ORGANIZED CONVECTION EXPECTED DUE TO NUMEROUS OUTFLOW BOUNDARY INTERACTIONS. WILL LEAVE MENTION OF CONVECTION FOR LATER TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR...FOLLOWED BY CHANCE FOR SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WINDS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531425 (Received by flhurricane at: 4:18 AM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS UPR-LVL LO PRES OVER EASTERN CANADA WITH AN ASSOCIATED TROF WELL EAST OF THE MID ATLANTIC. WEAK CYCLONIC FLOW ALOFT AND EMBEDDED PERTURBATIONS WILL LEAD TO ANOTHER CHC OF SHWRS AND TSTMS THIS AFTN AND EVNG AS THE ATM REMAINS MOIST FROM THE SFC TO 700 MB. ALTHO SHEAR IS VERY WEAK AND FORCING IS LACKING...SOME STORMS MAY BE STRONG AS LO-LVL LAPSE RATES WILL BE VERY STEEP AND LIFTED INDICES ARE PROGGED B/T -4 AND -7 PER LATEST NAM GUIDANCE. TEMPS WILL MAX OUT IN THE LOW TO MID 90S...WITH HEAT INDICES PEAKING IN THE UPR 90S. ANY CONVECTION WILL DISSIPATE TNGT FOLLOWING THE LOSS OF DAYTIME HEATING. LOW TEMPS OVRNGT MAINLY IN THE LOW 70S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 3-5KT OVERNIGHT. ADDITIONALLY...CURRENT DEWPOINT DEPRESSIONS ARE AROUND 5-8F AT THE TAF SITES. HENCE IFR CONDITIONS ARE NOT EXPECTED GIVEN THE COMBINATION OF A LIGHT WIND AND THE LATEST DEWPOINT DEPRESSIONS. THERE STILL COULD BE A PERIOD OF MVFR CONDITIONS AROUND SUNRISE MOST LIKELY OCCURRING AT RIC/SBY/ECG. OTHERWISE...THE SKY SHOULD BE MOSTLY CLEAR/MOSTLY SUNNY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531432 (Received by flhurricane at: 4:15 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 400 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHEN OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY/SUNDAY EVENING WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE-FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION. OTHERWISE...SCATTERED CONVECTION WILL LIKELY BE FOCUSED ALONG SEABREEZE BOUNDARIES OR OFF HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. A FEW STRONG TO SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW-LEVEL WINDS/SHEAR. MAIN THREAT WITH ANY STORMS WILL BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE WITH STRONG LOW-LEVEL WINDS. MAIN THREAT WILL BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO OVER 2 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS OVERNIGHT HOWEVER...REDUCED VISIBILITIES IN BR EXPECTED FOR SOME TERMINALS AFTER MAINLY 07Z. LOW CONFIDENCE REGARDING HOW LOW THEY GET REDUCED PARTICULARLY AT KHPN AND KGON. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ |
| #531423 (Received by flhurricane at: 4:15 AM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS UPR-LVL LO PRES OVER EASTERN CANADA WITH AN ASSOCIATED TROF WELL EAST OF THE MID ATLANTIC. WEAK CYCLONIC FLOW ALOFT AND EMBEDDED PERTURBATIONS WILL LEAD TO ANOTHER CHC OF SHWRS AND TSTMS THIS AFTN AND EVNG AS THE ATM REMAINS MOIST FROM THE SFC TO 700 MB. ALTHO SHEAR IS VERY WEAK AND FORCING IS LACKING...SOME STORMS MAY BE STRONG AS LO-LVL LAPSE RATES WILL BE VERY STEEP AND LIFTED INDICES ARE PROGGED B/T -4 AND -7 PER LATEST NAM GUIDANCE. TEMPS WILL MAX OUT IN THE LOW TO MID 90S...WITH HEAT INDICES PEAKING IN THE UPR 90S. ANY CONVECTION WILL DISSIPATE TNGT FOLLOWING THE LOSS OF DAYTIME HEATING. LOW TEMPS OVRNGT MAINLY IN THE LOW 70S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 3-5KT OVERNIGHT. ADDITIONALLY...CURRENT DEWPOINT DEPRESSIONS ARE AROUND 5-8F AT THE TAF SITES. HENCE IFR CONDITIONS ARE NOT EXPECTED GIVEN THE COMBINATION OF A LIGHT WIND AND THE LATEST DEWPOINT DEPRESSIONS. THERE STILL COULD BE A PERIOD OF MVFR CONDITIONS AROUND SUNRISE MOST LIKELY OCCURRING AT RIC/SBY/ECG. OTHERWISE...THE SKY SHOULD BE MOSTLY CLEAR/MOSTLY SUNNY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531424 (Received by flhurricane at: 4:15 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM THURSDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA...POSSIBLY ACCOMPANIED BY THUNDER...OVER LAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND MID LEVEL DYNAMICS WILL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. COULD BE ONE OF THOSE DAYS WHERE...CONVECTION BREAKS OUT ALONG THE IMMEDIATE COAST THROUGH MID TO LATE MORNING. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...LOW PROBABILITIES OF SHRA/TSRA OVERNIGHT. VFR CONDITIONS ARE LIKELY TO GIVE WAY TO MVFR VSBYS BY 08Z AS SKIES CLEAR. CONFIDENCE OF THE TIMING AND DURATION OF IFR LOW BUT GENERALLY FROM 09-11Z. VFR EXPECTED 1-2 HRS AFTER SUNRISE. CONVECTION SHOULD DEVELOP AFT 16Z BUT NO ORGANIZED CONVECTION EXPECTED DUE TO NUMEROUS OUTFLOW BOUNDARY INTERACTIONS. WILL LEAVE MENTION OF CONVECTION FOR LATER TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR...FOLLOWED BY CHANCE FOR SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WINDS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531421 (Received by flhurricane at: 4:12 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM THURSDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA...POSSIBLY ACCOMPANIED BY THUNDER...OVER LAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND MID LEVEL DYNAMICS WILL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. COULD BE ONE OF THOSE DAYS WHERE...CONVECTION BREAKS OUT ALONG THE IMMEDIATE COAST THROUGH MID TO LATE MORNING. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...LOW PROBABILITIES OF SHRA/TSRA OVERNIGHT. VFR CONDITIONS ARE LIKELY TO GIVE WAY TO MVFR VSBYS BY 08Z AS SKIES CLEAR. CONFIDENCE OF THE TIMING AND DURATION OF IFR LOW BUT GENERALLY FROM 09-11Z. VFR EXPECTED 1-2 HRS AFTER SUNRISE. CONVECTION SHOULD DEVELOP AFT 16Z BUT NO ORGANIZED CONVECTION EXPECTED DUE TO NUMEROUS OUTFLOW BOUNDARY INTERACTIONS. WILL LEAVE MENTION OF CONVECTION FOR LATER TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR...FOLLOWED BY CHANCE FOR SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WINDS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531420 (Received by flhurricane at: 4:12 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 400 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHEN OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY/SUNDAY EVENING WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE-FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION. OTHERWISE...SCATTERED CONVECTION WILL LIKELY BE FOCUSED ALONG SEABREEZE BOUNDARIES OR OFF HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. A FEW STRONG TO SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW-LEVEL WINDS/SHEAR. MAIN THREAT WITH ANY STORMS WILL BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE WITH STRONG LOW-LEVEL WINDS. MAIN THREAT WILL BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO OVER 2 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS OVERNIGHT HOWEVER...REDUCED VISIBILITIES IN BR EXPECTED FOR SOME TERMINALS AFTER MAINLY 07Z. LOW CONFIDENCE REGARDING HOW LOW THEY GET REDUCED PARTICULARLY AT KHPN AND KGON. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ |
| #531419 (Received by flhurricane at: 4:12 AM 03.Aug.2012) AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 357 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE COAST TODAY....AND WILL REMAIN OFF THE COAST THIS WEEKEND. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION EARLY MONDAY. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG HAS DEVELOPED EARLY THIS MORNING FROM THE BLUE RIDGE WEST AS SURFACE HIGH PRESSURE COVERS THE AREA. THE HIGH PRESSURE WILL SHIFT OFFSHORE DURING THE DAY AND AN INCREASING SOUTHERLY FLOW WILL KEEP A MOIST AIR MASS IN PLACE TODAY. 850MB TEMPERATURES AND DEW POINTS REMAIN ABOUT THE SAME TODAY AS YESTERDAY...AND WITH LITTLE CHANGE IN THE ATMOSPHERE HIGH TEMPERATURES WILL AGAIN BE IN THE MID 90/S. HEAT INDICES COULD EXCEED 100 DEGREES BETWEEN 2 PM AND 5 PM ESPECIALLY IN THE METRO AREAS BUT CONDITIONS SHOULD FALL SHORT OF A HEAT ADVISORY. THE COMPLEX OF STORMS CURRENTLY OVER INDIANA HAS SPREAD AN EXTENSIVE CLOUD SHIELD OVER OHIO THIS MORNING...AND SOME OF THESE ARE WORKING INTO PA/WV. THE WEAK SURFACE TROF NEAR ELKINS-WESTERN MD WILL LIFT NORTH AND WEST TODAY WHILE A WEAK UPPER TROF APPROACHES THE AREA LATER THIS AFTERNOON AND EVENING. SHOWERS AND THUNDERSTORMS WILL FIRE UP ALONG THE WESTERN MOUNTAINS BY EARLY AFTERNOON. AN ISOLATED STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE LATER IN THE AFTERNOON AS MOISTURE AND INSTABILITY IS RECIRCULATED. THE NAM KEEPS THE TROF OVER THE WVA PANHANDLE OVERNIGHT...CONTINUING THE RISK OF THUNDERSTORMS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... THIS WKND CWFA WL BE BTWN HIPRES RDG IN THE WRN ATLC AND A CDFNT/H5 VORTMAX CROSSING THE GRTLKS. THE UPA PTTN FEATURES WLY FLOW MAINLY CONFINED TO THE NRN CONUS...W/ BROAD HIPRES ACRS THE SRN STATES. THAT/LL LEAD TO TYPICAL HEAT AND HUMIDITY...WHICH WL CULMINATE IN LT DAY TSRA. NO BIG CHGS TO TEMP FCSTS...PER MOS CONSISTENCY. SAT ACTIVITY WL FEED OFF OF TRRN CIRCULATIONS...THTE MAX...AND MESOSCALE BNDRYS-- THE LATTER OF WHICH WL BE DFCLT TO PIN DWN FM THIS STANDPOINT. HV BUMPED UP POPS AREAWIDE...AND ATTEMPTED TO ADD A LTL PLACEMENT/TIMING DETAIL NONETHELESS. USED CLIMO A BIT IN TIMING...ORIGINATING TSRA IN MTNS BY ELY AFTN...EVOLVING INTO LEE TROF ELY EVNG...AND THEN PUSHING TWD DELMARVA AFDK. SUN WL BE INFLUENCED MORE BY THE APPCHG BNDRY/UPR TROF...WORKING ON AN UNSTBL AMS. NAM/GFS/ECMWF SEEM TO HV DECENT HANDLE ON TIMING...W/ A SUN NGT CFP. DYNAMICS AND LAPSE RATES PREFERRED N OF CWFA...WHICH IS WHERE THE HIER POPS WERE PLACED. THAT/S NOT TO DISCOUNT STRENGTH OF ACTIVITY W/IN CWFA...AS THERE/S MORE THAN ADEQUATE INSTBY/SHEAR...SPCLY FOR NRN CNTYS. MENTION OF SVR IN HWO WUD APPEAR JUSTIFIED. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PATTERN WL BE DOMINATED BY AN UPPER LVL RDG OVR THE ROCKY MTNS AND SLT TROFFING IN THE ERN U.S. BECAUSE OF THIS THE REALLY HIGH HEAT IS XPCTD TO BE HELD AT BAY THRU THE 1ST WK OF AUG. AFTR THE FNT MOVES THRU...AND THERE`S NO GUARANTEE AT THIS TIME OF THE YR THAT IT WL...UPR TROF SHOULD BE A CONTROLLER. AS MENTIONED ABV TEMPS SHOULD NOT GO MUCH ABV THE CLIMO NORMS...BUT ALMOST ALL SUMMER MDL TEMP FCSTS HV NOT BEEN WARM ENUF. THE FLIP IS THERE WAS ONE TIME THIS SUMMER (THAT I CAN RECALL) WHERE AFTR A FNT WENT THRU WE MOVED INTO A CAD ENVIRONMENT AND TEMPS ACTUALLY WERE BLO NORMS. FOR TIME BEING WL KEEP HIGHS IN U80S/LOWS 65-70. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS EXPECTED AT THE BWI...IAD AND DCA TERMINALS FOR THE NEXT 24 HOURS. MVFR 3-5SM BR LIKELY WEST OF THE BLUE RIDGE UNTIL 12Z...AND LOCALLY NEAR THE CHESAPEAKE BAY. SCT-BKN HIGH CLOUDS FL250 WILL SPREAD OVER THE AREA AS A FRONTAL SYSTEM WEAKENS TO THE NORTH. CUMULUS CLOUDS BASES FL050 POSSIBLE BY LATE AFTERNOON WITH LESS THAN A 20 PERCENT CHANCE OF A TS AT THE MAJOR TERMINALS THRU 22Z. SFC WINDS 18010KT. THIS CHANCE INCREASES TO 30 PERCENT BETWEEN 22Z AND 03Z...THEN DECREASES OVERNIGHT. FLGT RESTRICTIONS PSBL W/IN MAINLY DIURNAL TSRA SAT AND SUN. CVRG SUN MAY BE TIMED A LTL LATER DUE TO CFP. REDUCTIONS WUD BE BRIEF... POTENTIALLY DOWN TO IFR. ALSO MAY HV ELY MRNG VSBY RESTRICTIONS... MVFR MOST LKLY...THO IFR PSBL INVOF AREAS WHICH RECVD TSRA FM THE PRVS DAY. && .MARINE... SOUTHERLY CHANNELING COULD CAUSE SOME BREEZY AFTERNOON WINDS TODAY BUT EXPECTED TO REMAIN BELOW SCA CONDITIONS. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN THIS AFTERNOON. LOCALLY GUSTY WINDS AND LIGHTNING ARE POSSIBLE NEAR STORMS. SLY CHANNELING PSBL SAT EVNG...AND AGN LT SUN AHD OF CDFNT. POTL SCA FOR EACH OCCASION. ALSO WL HV TSRA DAILY TO CONTEND WITH...ANY OF WHICH MAY CONTAIN GUSTY WINDS. SMW/S PSBL. FROPA EITHER LT SUN OR ELY MON. && .TIDES/COASTAL FLOODING... WATER LEVELS ARE FORECAST TO BE CLOSE...BUT JUST BELOW MINOR TIDAL FLOODING THRESHOLDS. WILL HAVE TO WATCH SENSITIVE LOCATIONS SUCH AS ANNAPOLIS FOR POSSIBLE MINOR TIDAL FLOODING LATER THIS MORNING. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...HTS |
| #531418 (Received by flhurricane at: 4:12 AM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS UPR-LVL LO PRES OVER EASTERN CANADA WITH AN ASSOCIATED TROF WELL EAST OF THE MID ATLANTIC. WEAK CYCLONIC FLOW ALOFT AND EMBEDDED PERTURBATIONS WILL LEAD TO ANOTHER CHC OF SHWRS AND TSTMS THIS AFTN AND EVNG AS THE ATM REMAINS MOIST FROM THE SFC TO 700 MB. ALTHO SHEAR IS VERY WEAK AND FORCING IS LACKING...SOME STORMS MAY BE STRONG AS LO-LVL LAPSE RATES WILL BE VERY STEEP AND LIFTED INDICES ARE PROGGED B/T -4 AND -7 PER LATEST NAM GUIDANCE. TEMPS WILL MAX OUT IN THE LOW TO MID 90S...WITH HEAT INDICES PEAKING IN THE UPR 90S. ANY CONVECTION WILL DISSIPATE TNGT FOLLOWING THE LOSS OF DAYTIME HEATING. LOW TEMPS OVRNGT MAINLY IN THE LOW 70S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 3-5KT OVERNIGHT. ADDITIONALLY...CURRENT DEWPOINT DEPRESSIONS ARE AROUND 5-8F AT THE TAF SITES. HENCE IFR CONDITIONS ARE NOT EXPECTED GIVEN THE COMBINATION OF A LIGHT WIND AND THE LATEST DEWPOINT DEPRESSIONS. THERE STILL COULD BE A PERIOD OF MVFR CONDITIONS AROUND SUNRISE MOST LIKELY OCCURRING AT RIC/SBY/ECG. OTHERWISE...THE SKY SHOULD BE MOSTLY CLEAR/MOSTLY SUNNY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531428 (Received by flhurricane at: 4:09 AM 03.Aug.2012) AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 357 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFF THE COAST TODAY....AND WILL REMAIN OFF THE COAST THIS WEEKEND. A COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION EARLY MONDAY. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG HAS DEVELOPED EARLY THIS MORNING FROM THE BLUE RIDGE WEST AS SURFACE HIGH PRESSURE COVERS THE AREA. THE HIGH PRESSURE WILL SHIFT OFFSHORE DURING THE DAY AND AN INCREASING SOUTHERLY FLOW WILL KEEP A MOIST AIR MASS IN PLACE TODAY. 850MB TEMPERATURES AND DEW POINTS REMAIN ABOUT THE SAME TODAY AS YESTERDAY...AND WITH LITTLE CHANGE IN THE ATMOSPHERE HIGH TEMPERATURES WILL AGAIN BE IN THE MID 90/S. HEAT INDICES COULD EXCEED 100 DEGREES BETWEEN 2 PM AND 5 PM ESPECIALLY IN THE METRO AREAS BUT CONDITIONS SHOULD FALL SHORT OF A HEAT ADVISORY. THE COMPLEX OF STORMS CURRENTLY OVER INDIANA HAS SPREAD AN EXTENSIVE CLOUD SHIELD OVER OHIO THIS MORNING...AND SOME OF THESE ARE WORKING INTO PA/WV. THE WEAK SURFACE TROF NEAR ELKINS-WESTERN MD WILL LIFT NORTH AND WEST TODAY WHILE A WEAK UPPER TROF APPROACHES THE AREA LATER THIS AFTERNOON AND EVENING. SHOWERS AND THUNDERSTORMS WILL FIRE UP ALONG THE WESTERN MOUNTAINS BY EARLY AFTERNOON. AN ISOLATED STORM WILL BE POSSIBLE JUST ABOUT ANYWHERE LATER IN THE AFTERNOON AS MOISTURE AND INSTABILITY IS RECIRCULATED. THE NAM KEEPS THE TROF OVER THE WVA PANHANDLE OVERNIGHT...CONTINUING THE RISK OF THUNDERSTORMS. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... THIS WKND CWFA WL BE BTWN HIPRES RDG IN THE WRN ATLC AND A CDFNT/H5 VORTMAX CROSSING THE GRTLKS. THE UPA PTTN FEATURES WLY FLOW MAINLY CONFINED TO THE NRN CONUS...W/ BROAD HIPRES ACRS THE SRN STATES. THAT/LL LEAD TO TYPICAL HEAT AND HUMIDITY...WHICH WL CULMINATE IN LT DAY TSRA. NO BIG CHGS TO TEMP FCSTS...PER MOS CONSISTENCY. SAT ACTIVITY WL FEED OFF OF TRRN CIRCULATIONS...THTE MAX...AND MESOSCALE BNDRYS-- THE LATTER OF WHICH WL BE DFCLT TO PIN DWN FM THIS STANDPOINT. HV BUMPED UP POPS AREAWIDE...AND ATTEMPTED TO ADD A LTL PLACEMENT/TIMING DETAIL NONETHELESS. USED CLIMO A BIT IN TIMING...ORIGINATING TSRA IN MTNS BY ELY AFTN...EVOLVING INTO LEE TROF ELY EVNG...AND THEN PUSHING TWD DELMARVA AFDK. SUN WL BE INFLUENCED MORE BY THE APPCHG BNDRY/UPR TROF...WORKING ON AN UNSTBL AMS. NAM/GFS/ECMWF SEEM TO HV DECENT HANDLE ON TIMING...W/ A SUN NGT CFP. DYNAMICS AND LAPSE RATES PREFERRED N OF CWFA...WHICH IS WHERE THE HIER POPS WERE PLACED. THAT/S NOT TO DISCOUNT STRENGTH OF ACTIVITY W/IN CWFA...AS THERE/S MORE THAN ADEQUATE INSTBY/SHEAR...SPCLY FOR NRN CNTYS. MENTION OF SVR IN HWO WUD APPEAR JUSTIFIED. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PATTERN WL BE DOMINATED BY AN UPPER LVL RDG OVR THE ROCKY MTNS AND SLT TROFFING IN THE ERN U.S. BECAUSE OF THIS THE REALLY HIGH HEAT IS XPCTD TO BE HELD AT BAY THRU THE 1ST WK OF AUG. AFTR THE FNT MOVES THRU...AND THERE`S NO GUARANTEE AT THIS TIME OF THE YR THAT IT WL...UPR TROF SHOULD BE A CONTROLLER. AS MENTIONED ABV TEMPS SHOULD NOT GO MUCH ABV THE CLIMO NORMS...BUT ALMOST ALL SUMMER MDL TEMP FCSTS HV NOT BEEN WARM ENUF. THE FLIP IS THERE WAS ONE TIME THIS SUMMER (THAT I CAN RECALL) WHERE AFTR A FNT WENT THRU WE MOVED INTO A CAD ENVIRONMENT AND TEMPS ACTUALLY WERE BLO NORMS. FOR TIME BEING WL KEEP HIGHS IN U80S/LOWS 65-70. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS EXPECTED AT THE BWI...IAD AND DCA TERMINALS FOR THE NEXT 24 HOURS. MVFR 3-5SM BR LIKELY WEST OF THE BLUE RIDGE UNTIL 12Z...AND LOCALLY NEAR THE CHESAPEAKE BAY. SCT-BKN HIGH CLOUDS FL250 WILL SPREAD OVER THE AREA AS A FRONTAL SYSTEM WEAKENS TO THE NORTH. CUMULUS CLOUDS BASES FL050 POSSIBLE BY LATE AFTERNOON WITH LESS THAN A 20 PERCENT CHANCE OF A TS AT THE MAJOR TERMINALS THRU 22Z. SFC WINDS 18010KT. THIS CHANCE INCREASES TO 30 PERCENT BETWEEN 22Z AND 03Z...THEN DECREASES OVERNIGHT. FLGT RESTRICTIONS PSBL W/IN MAINLY DIURNAL TSRA SAT AND SUN. CVRG SUN MAY BE TIMED A LTL LATER DUE TO CFP. REDUCTIONS WUD BE BRIEF... POTENTIALLY DOWN TO IFR. ALSO MAY HV ELY MRNG VSBY RESTRICTIONS... MVFR MOST LKLY...THO IFR PSBL INVOF AREAS WHICH RECVD TSRA FM THE PRVS DAY. && .MARINE... SOUTHERLY CHANNELING COULD CAUSE SOME BREEZY AFTERNOON WINDS TODAY BUT EXPECTED TO REMAIN BELOW SCA CONDITIONS. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN THIS AFTERNOON. LOCALLY GUSTY WINDS AND LIGHTNING ARE POSSIBLE NEAR STORMS. SLY CHANNELING PSBL SAT EVNG...AND AGN LT SUN AHD OF CDFNT. POTL SCA FOR EACH OCCASION. ALSO WL HV TSRA DAILY TO CONTEND WITH...ANY OF WHICH MAY CONTAIN GUSTY WINDS. SMW/S PSBL. FROPA EITHER LT SUN OR ELY MON. && .TIDES/COASTAL FLOODING... WATER LEVELS ARE FORECAST TO BE CLOSE...BUT JUST BELOW MINOR TIDAL FLOODING THRESHOLDS. WILL HAVE TO WATCH SENSITIVE LOCATIONS SUCH AS ANNAPOLIS FOR POSSIBLE MINOR TIDAL FLOODING LATER THIS MORNING. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...HTS |
| #531417 (Received by flhurricane at: 4:09 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA BY MID WEEK...BUT COULD LINGER INTO THURSDAY...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM THURSDAY...LATEST 88D RADAR SURVEILLANCE ILLUSTRATES ISOLATED SHRA...POSSIBLY ACCOMPANIED BY THUNDER...OVER LAND AREAS OF THE ILM CWA. WITH A MID-LEVEL VORT/IMPULSE HAVING TEMPORARILY STALLED ACROSS THE ILM CWA...THE DYNAMICS FROM THIS FEATURE WILL AID THE DEVELOPMENT OF CONVECTION ACROSS THE ILM CWA AT BASICALLY ANYTIME OF THE 24 HR DAY...ENDING SATURDAY MORNING. MODELS INDICATE THIS FEATURE TO BEGIN LIFTING NORTHWARD BY SATURDAY MORNING. AS FOR TODAY...INSOLATION...THE SEA BREEZE...AND MID LEVEL DYNAMICS WILL COMBINE FORCES AND PRODUCE SCATTERED CONVECTION ACROSS THE FA. COULD BE ONE OF THOSE DAYS WHERE...CONVECTION BREAKS OUT ALONG THE IMMEDIATE COAST THROUGH MID TO LATE MORNING. THE ACTIVITY THEN TRANSLATES INLAND DURING THIS AFTERNOON/EVENING. PROGGED LAPSE RATES ACROSS THE FA TODAY WILL NOT NEARLY BE AS PRONOUNCED OR STEEP LIKE YESTERDAY AFTERNOON AND EVENING. THIS A RESULT OF THE COLD POOL ALOFT HAVING MODIFIED SOME. HAVE OPTED TO COMPROMISE BETWEEN THE NAM AND GFS MOS GUIDANCE FOR TEMPS THROUGHOUT THE NEAR TERM. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...RIDGE BUILDS IN FROM THE EAST ON SATURDAY AS HEIGHTS RISE UP TO 594 DM. NORTHERN STREAM MID TO UPPER TROUGH TRIES TO DIG DOWN PUSHING A COLD FRONT INTO THE CAROLINAS BUT LOOKS LIKE RIDGE WILL HOLD THIS SYSTEM BACK UNTIL AT LEAST AFTER THE WEEKEND. A DEEP S-SE ON SHORE FLOW DEVELOPS THROUGH SATURDAY...BUT MODELS SHOW PLENTY OF DRY AIR WITH PCP WATER VALUES DOWN TO AROUND 1.5 INCHES SAT AFTN. THE RIDGING ALOFT WITH PLENTY OF MID TO UPPER LEVEL DRY AIR WILL HELP SUPPRESS CONVECTION ON SAT BUT BY SUNDAY MOISTURE RETURNS. MODELS SHOWING A TROPICAL WAVE REACHING INTO FLORIDA ON SUNDAY WITH A TROUGH EXTENDING UP THROUGH THE OFF SHORE WATERS. CLOUDS AND PCP ASSOCIATED WITH THIS TROUGH WILL REACH AREA IN DEEP SOUTHERLY FLOW. PCP WATER VALUES REACH UP OVER 2.25 INCHES AS TROUGH PUSHES ON SHORE. GFS IS MUCH QUICKER WITH THIS FEATURE WITH ARRIVAL LATE SAT BUT NAM BRINGS IN ON SHORE THROUGH SUNDAY. THEREFORE EXPECT QUIETER WEATHER ON THE WHOLE WITH LACK OF UPPER LEVEL SUPPORT...BUT THE FORECAST WILL DEPEND ON THIS MOISTURE MAKING ITS WAY ON SHORE OVER THE SOUTHEAST. FOR NOW WILL KEEP WITH MAINLY MORE LOCALIZED DIURNAL CONVECTION FLARING FARTHER INLAND AND ALONG THE SEA BREEZE BOUNDARY. ALSO WILL INCLUDE A FAIR AMOUNT OF CLOUDS WHICH MAY KEEP TEMPS DOWN A BIT...BUT BASICALLY HOVERING RIGHT AROUND NORMAL WITH READINGS AROUND 90 MOST PLACES AND 70S OVERNIGHT. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM FRIDAY...LATEST MODEL RUNS KEEP RIDGE OVER AREA HOLDING BACK FRONT TO THE WESTERN CAROLINAS MONDAY INTO TUES. BASICALLY WILL SEE DEEP SOUTHERLY FLOW CONTINUE THROUGH THE WEEK WITH THIS MOIST FLOW INCREASING THROUGH MID WEEK AS FRONT APPROACHES FROM THE NW. LOOKS LIKE MID TO UPPER TROUGH WILL EVENTUALLY PUSH THIS FRONT EAST INTO AREA BY MID WEEK WITH INCREASING CHC OF PCP BY LATE TUES INTO WED AND POSSIBLY LINGERING INTO THURS. FOR NOW WILL KEEP SLIGHT CHC TO CHC POPS THROUGH THE PERIOD WITH FOCUS MORE LOCALIZED ALONG SEA BREEZE MON INTO TUES AND GREATEST CHC ON WED INTO THURS ASSOCIATED WITH FRONT MOVING IN. TEMPS WILL HOVER AROUND NORMAL AND SHOULD RUN SLIGHTLY LOWER MID WEEK WITH GREATER CLOUD COVER AND PCP CHANCES. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...LOW PROBABILITIES OF SHRA/TSRA OVERNIGHT. VFR CONDITIONS ARE LIKELY TO GIVE WAY TO MVFR VSBYS BY 08Z AS SKIES CLEAR. CONFIDENCE OF THE TIMING AND DURATION OF IFR LOW BUT GENERALLY FROM 09-11Z. VFR EXPECTED 1-2 HRS AFTER SUNRISE. CONVECTION SHOULD DEVELOP AFT 16Z BUT NO ORGANIZED CONVECTION EXPECTED DUE TO NUMEROUS OUTFLOW BOUNDARY INTERACTIONS. WILL LEAVE MENTION OF CONVECTION FOR LATER TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR...FOLLOWED BY CHANCE FOR SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM FRIDAY...RIDGING FROM THE WESTERN ATLANTIC HIGH TO BUILD AND DOMINATE THE SYNOPTIC FLOW ACROSS THE AREA WATERS. THE RIDGE AXIS FROM THIS HIGH WILL SLOWLY LIFT NORTHWARD RESULTING WITH WINDS BECOMING ONSHORE...SSE-S FLOW. SFC PG TO SUPPORT 10-15 KT. AS FOR SIG SEAS...LOOKING AT A SOLID 3 FT THROUGHOUT THE FORECAST PERIOD ...POSSIBLY REACHING 4 FT ACROSS THE OUTER WATERS OFF CAPE FEAR. LOOK FOR DOMINATE PERIODS OF 8 TO 9 SECONDS VIA LATEST WAVEWATCH3 GUIDANCE. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY...SOUTHERLY FLOW AROUND 10 KTS WILL CONTINUE AROUND BERMUDA HIGH THROUGH THE WEEKEND. SHOULD SEE SLIGHT INCREASE IN WINDS EACH AFTERNOON NEAR SHORE AS SEA BREEZE KICKS IN. WITH WINDS REMAINING FAIRLY LIGHT...THE SEAS WILL REMAIN 3 FT OR LESS MIXING WITH A SLIGHTLY LONGER UP TO 9 SEC SE SWELL. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 300 AM FRIDAY...CONTINUED SOUTHERLY WINDS AROUND BERMUDA HIGH WITH OVERALL BENIGN MARINE CONDITIONS. SEAS MAINTAIN 3 FT OR LESS WITH WINDS AROUND 10 KTS OR LESS. SEAS WILL MIX WITH A SLIGHTLY LONGER PERIOD SE SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531416 (Received by flhurricane at: 4:09 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 400 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHEN OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY/SUNDAY EVENING WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE-FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION. OTHERWISE...SCATTERED CONVECTION WILL LIKELY BE FOCUSED ALONG SEABREEZE BOUNDARIES OR OFF HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. A FEW STRONG TO SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW-LEVEL WINDS/SHEAR. MAIN THREAT WITH ANY STORMS WILL BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE WITH STRONG LOW-LEVEL WINDS. MAIN THREAT WILL BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO OVER 2 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS OVERNIGHT HOWEVER...REDUCED VISIBILITIES IN BR EXPECTED FOR SOME TERMINALS AFTER MAINLY 07Z. LOW CONFIDENCE REGARDING HOW LOW THEY GET REDUCED PARTICULARLY AT KHPN AND KGON. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ |
| #531435 (Received by flhurricane at: 4:09 AM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 356 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL STAY CENTERED OFF THE SOUTHEAST COAST TODAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS UPR-LVL LO PRES OVER EASTERN CANADA WITH AN ASSOCIATED TROF WELL EAST OF THE MID ATLANTIC. WEAK CYCLONIC FLOW ALOFT AND EMBEDDED PERTURBATIONS WILL LEAD TO ANOTHER CHC OF SHWRS AND TSTMS THIS AFTN AND EVNG AS THE ATM REMAINS MOIST FROM THE SFC TO 700 MB. ALTHO SHEAR IS VERY WEAK AND FORCING IS LACKING...SOME STORMS MAY BE STRONG AS LO-LVL LAPSE RATES WILL BE VERY STEEP AND LIFTED INDICES ARE PROGGED B/T -4 AND -7 PER LATEST NAM GUIDANCE. TEMPS WILL MAX OUT IN THE LOW TO MID 90S...WITH HEAT INDICES PEAKING IN THE UPR 90S. ANY CONVECTION WILL DISSIPATE TNGT FOLLOWING THE LOSS OF DAYTIME HEATING. LOW TEMPS OVRNGT MAINLY IN THE LOW 70S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... FRI WX CONDITIONS CONTINUE INTO THE WEEKEND. BERMUDA HI PRES EXPANDS WESTWARDS ALLOWING FOR CONTINUED SOUTHERLY FLOW AND ABOVE NORMAL TEMPS OVER THE MID ATLANTIC. MAIN FRNTAL BNDRY WILL REMAIN WEST OF THE AREA THRU THE WEEKEND BUT WEAK MID-LVL ENERGY...MOIST FLOW...AND SFC BNDRYS WILL BE ENUF TO CARRY 20-30% POPS THRU THE PERIOD. SKIES WILL AVG PRTLY CLDY WITH HI TEMPS IN THE LOW TO MID 90S BOTH DAYS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 3-5KT OVERNIGHT. ADDITIONALLY...CURRENT DEWPOINT DEPRESSIONS ARE AROUND 5-8F AT THE TAF SITES. HENCE IFR CONDITIONS ARE NOT EXPECTED GIVEN THE COMBINATION OF A LIGHT WIND AND THE LATEST DEWPOINT DEPRESSIONS. THERE STILL COULD BE A PERIOD OF MVFR CONDITIONS AROUND SUNRISE MOST LIKELY OCCURRING AT RIC/SBY/ECG. OTHERWISE...THE SKY SHOULD BE MOSTLY CLEAR/MOSTLY SUNNY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST TODAY THROUGH EARLY NEXT WEEK. LOW PRESSURE TRACKS FROM THE GREAT LAKES ENE ACROSS THE SAINT LAWRENCE VALLEY SUNDAY AND SUNDAY NIGHT. THIS LOW PRESSURE SYSTEM DRAGS A WEAKENING COLD FRONT INTO THE MID ATLANTIC EARLY NEXT WEEK. THE WIND SHOULD MAINLY BE OUT OF THE SSW WITH SPEEDS AOB 15KT THROUGH SATURDAY NIGHT. THE PRESSURE GRADIENT TIGHTENS SUNDAY AND SUNDAY NIGHT IN RESPONSE TO LOW PRESSURE MOVING N OF THE REGION AND HIGH PRESSURE HOLDING STRONG OVER THE ATLANTIC. THIS COULD BRING MARGINAL SCA CONDITIONS TO THE MARINE AREA AS WIND SPEEDS APPROACH 20KT (OUT OF THE SSW)...ESPECIALLY ACROSS THE NORTHERN COASTAL ZONES WHERE SEAS COULD REACH 5FT OUT NEAR 20NM. OTHERWISE...SEAS SHOULD GENERALLY BE 2-3FT. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS |
| #531415 (Received by flhurricane at: 4:06 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 400 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL MAINLY INFLUENCE THE WEATHER ACROSS THE TRI-STATE REGION THROUGH SATURDAY AS THE BERMUDA HIGH STRENGTHEN OFF THE EASTERN SEABOARD. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... WARMING HEIGHTS ALOFT AND AN ONSHORE FLOW WILL PRODUCE HOT AND HUMID CONDITIONS ACROSS THE FORECAST AREA TODAY. HEAT INDEX VALUES WILL APPROACH 95 FOR NYC...BUT THERE IS ONLY LOW CONFIDENCE FOR THE TWO CONSECUTIVE DAYS NEEDED TO ISSUE A HEAT ADVISORY. THIS BEING AUGUST AND WITH SEVERAL HEAT WAVES UNDER OUR BELT...PREFERRED TO HOLD OFF AT THIS TIME WITH ONLY MARGINAL VALUES. AS FOR ANY CONVECTION...WITH HEIGHTS CONTINUING TO WARM ALOFT...A DRY VERTICAL MOISTURE PROFILE....AND LITTLE FORCING ALOFT AND AT THE SFC...JUST WENT WITH A SLIGHT CHC ACROSS THE INTERIOR. THE MAIN TRIGGER WILL BE DIFFERENTIAL HEATING DRIVEN BY THE HILLS NORTH AND WEST OF NYC. A MODERATELY UNSTABLE...WEAKLY SHEARED ENVIRONMENT COULD PRODUCE A FEW PULSE STORMS. USED MET/MAV MOS FOR HIGHS TODAY...WITH READINGS RANGING FROM THE MID TO UPPER 80S AT THE COAST...TO 90 TO 95 NYC METRO AND THE INTERIOR. THERE IS MODERATE RISK OF RIP CURRENTS TODAY AT THE OCEAN BEACHES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM...MUGGY CONDITIONS WILL CONTINUE TONIGHT INTO SATURDAY WITH A NEAR CARBON COPY OF TODAY. THE FLOW LOOKS TO BE MORE S/SE WHICH SHOULD ALLOW FOR MORE OF A MARINE INFLUENCE INLAND. THIS WILL ALLOW FOR SLIGHTLY COOLER HIGHS ON SAT...BUT HIGHER DEW POINTS... RESULTING IN PRETTY MUCH A WASH. 594 DM HEIGHTS ASSOC WITH THE SUB TROP HIGH OFF THE EAST COAST BUILD WESTWARD ON SAT. THUS...ANOTHER WARM DAY ALOFT...WHICH SHOULD PRETTY MUCH PUT A LID ON ANY WIDESPREAD CONVECTION. SHOULD BE SIMILAR TO FRIDAY WITH JUST A SLIGHT CHC ACROSS THE INTERIOR. ONCE AGAIN USED A BLEND OF MET/MAV MOS. TEMPS ARE ABOUT 4 TO 8 DEGREES ABOVE NORMAL WITH RESPECT TO BOTH HIGHS AND LOWS. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... THE REGION WILL BE IN A SUB-TROPICAL REGIME THROUGH MUCH OF THE PERIOD WITH PERSISTENT WESTERN ATLANTIC RIDGING AND HUDSONS BAY TROUGHING. A SHARP NORTHERN STREAM SHORTWAVE WILL TRACK THROUGH THE GREAT LAKES ON SATURDAY NIGHT INTO SUNDAY...AND THEN WEAKEN AS IT LIFTS THROUGH NEW ENGLAND SUN NIGHT INTO MONDAY. AT THE SURFACE...A COLD FRONT WILL TRACK EAST THROUGH THE GREAT LAKES ON SAT NIGHT INTO SUNDAY...WITH AN ASSOCIATED WARM FRONT LIFTING THROUGH THE REGION SUNDAY MORNING AND PRE-FRONTAL TROUGH APPROACHING LATE SUNDAY. THE COLD FRONT ITSELF CROSSES THROUGH THE REGION ON MONDAY. ANY CONVECTION SHOULD GRADUALLY DISSIPATE SATURDAY EVENING WITH WANING INSTABILITY. OTHERWISE...ISOLATED SHRA/TSRA POTENTIAL OVERNIGHT WITH MODELS HINTING AT LEAD SHORTWAVE ENERGY LIFTING THROUGH AND MARGINAL INSTABILITY. A FEW SHOWERS/ISOLATED TSTMS POSSIBLE WITH THE WARM FRONTAL PASSAGE SUNDAY MORNING AS LLJ BEGINS TO STRENGTHEN. INCREASING CHANCE OF THUNDERSTORMS LATE SUNDAY/SUNDAY EVENING WITH FALLING HEIGHTS AHEAD OF THE APPROACHING SHORTWAVE TROUGH AND APPROACHING PRE-FRONTAL TROUGH. UNCERTAINTY EXISTS ON COVERAGE OF STORMS ON SUNDAY AFTERNOON...AS IT DEPENDS ON HOW FAR EAST THE PRE-FRONTAL TROUGH MAKES IT DURING THE AFTERNOON/EARLY EVENING. IF THE PRE-FRONTAL TROUGH CAN WORK INTO WESTERN PORTIONS OF THE REGION BY LATE IN THE DAY...THIS COULD ACT AS A FOCUS FOR AN ORGANIZED LINE OF STRONG TO SEVERE CONVECTION. OTHERWISE...SCATTERED CONVECTION WILL LIKELY BE FOCUSED ALONG SEABREEZE BOUNDARIES OR OFF HIGHER ELEVATIONS AND OUTFLOW BOUNDARIES IN A LOW CIN ENVIRONMENT. A FEW STRONG TO SEVERE STORMS ARE NOT OUT OF THE QUESTION WITH MODERATE TO HIGH INSTABILITY AND INCREASING LOW-LEVEL WINDS/SHEAR. MAIN THREAT WITH ANY STORMS WILL BE TORRENTIAL DOWNPOURS AND POTENTIAL FOR LOCALIZED FLASH FLOODING WITH BACK BUILDING BASED ON THE LOW/MID LEVELS WINDS. INCREASING POTENTIAL FOR HEAVY SHOWERS/THUNDERSTORMS SUNDAY NIGHT CONTINUING INTO MONDAY MORNING WITH SHORTWAVE APPROACH AND PRE-FRONTAL TROUGH/COLD FRONT ENTERING AND CROSSING THE REGION. SEVERE THREAT WILL DIMINISH SUNDAY EVENING...BUT STRONG STORMS POSSIBLE WITH STRONG LOW-LEVEL WINDS. MAIN THREAT WILL BE FLOODING SUNDAY NIGHT INTO MONDAY MORNING WITH PWATS INCREASING TO OVER 2 INCHES AND TRAINING POTENTIAL AS LO/MID LEVEL WINDS NEARLY ALIGN WITH THE FRONT. COLD FRONT PUSHES THROUGH THE REGION THROUGH MONDAY MORNING/AFTERNOON...WITH SHOWER/TSTM THREAT TAPERING FROM W TO E. GRADUAL DRYING CONDITIONS EXPECTED IN THE WAKE OF THE FRONT MON AFTERNOON/NIGHT. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS OVERNIGHT HOWEVER...REDUCED VISIBILITIES IN BR EXPECTED FOR SOME TERMINALS AFTER MAINLY 07Z. LOW CONFIDENCE REGARDING HOW LOW THEY GET REDUCED PARTICULARLY AT KHPN AND KGON. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY FLOW TO AROUND 10 KT CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. WINDS ARE EXPECTED TO DIMINISH FROM W TO E MONDAY MORNING...BUT OCEAN SEAS WILL LIKELY TAKES UNTIL MONDAY NIGHT TO FALL BELOW SCA LEVELS. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING TODAY AND SATURDAY. PRIMARY AREA OF CONCERN IS TO THE NORTH AND WEST OF NYC. THUNDERSTORMS WILL BE CAPABLE OF TORRENTIAL RAINS SUNDAY AFTERNOON INTO MONDAY MORNING. URBAN AND POOR DRAINAGE FLOODING WILL BE A THREAT WITH ANY CONVECTION...WITH A THREAT FOR FLASH FLOODING FROM BACK BUILDING OR TRAINING STORMS. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ |
| #531414 (Received by flhurricane at: 3:57 AM 03.Aug.2012) AFDPHI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 354 AM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN ACROSS THE MIDDLE ATLANTIC TODAY WHILE A WEAK COLD FRONT REMAINS TO THE NORTH ACROSS NEW ENGLAND. IT WILL REMAIN HOT AND HUMID THIS WEEKEND AS THE HIGH OFF THE EAST COAST BRINGS MORE SUMMER-LIKE CONDITIONS TO THE REGION. A COLD FRONT WILL CROSS THE AREA SUNDAY NIGHT AND EARLY MONDAY. THIS FRONT WILL REMAIN TO THE SOUTH OF THE REGION WHILE ANOTHER HIGH PRESSURE SYSTEM BUILDS IN FROM THE NORTH THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... OVERALL A FAIRLY QUITE DAY EXPECTED TODAY. A WEAK COLD FRONT WILL BE MOVING THROUGH THE GREAT LAKES, BUT WILL LIKELY NOT MAKE IT MUCH FARTHER THAN CENTRAL NEW YORK/PENNSYLVANIA THIS AFTERNOON BEFORE STALLING OUT. HIGH PRESSURE SLIGHTLY BULGING INTO THE AREA FROM OVER THE OCEAN WILL CONTINUE WILL KEEP US IN A GENERAL SOUTH-SOUTHWESTERLY FLOW. THICKNESSES WILL INCREASE TODAY, AND WITH 850 MB TEMPERATURES IN THE MID-UPPER TEENS, WE EXPECT TEMPERATURES TO TOP OUT IN THE LOW 90S. THE DEW POINTS MAY DROP A LITTLE DURING THE DAY, BUT WE STILL EXPECT HEAT INDEXES IN THE PHILLY METRO AREA TO TOP OUT AROUND 100 DEGREES. A HEAT ADVISORY IS ALREADY IN PLACE, SO WE WILL KEEP IT AS IS FOR NOW. THE REST OF THE AREA SHOULD REMAIN BELOW THEIR ADVISORY CRITERIA, SO WE LEFT THEM OUT. WITH THE FRONT EXPECTED TO REMAIN TO OUR NORTH, AND NO STRONG SHORT WAVE/VORT MAXES EXPECTED, WIDESPREAD CONVECTION IS NOT ANTICIPATED TODAY. HOWEVER, WITH PWATS AROUND 1.5 INCHES AND A FAIR AMOUNT OF INSTABILITY DURING THE DAY /CAPES AROUND 1,500 J/KG; LI`S AROUND -4/ WE COULD HAVE SOME INSTABILITY TYPE SHOWERS/THUNDERSTORMS DEVELOP. ANYTHING THAT DOES DEVELOP IS EXPECTED TO BE ISOLATED, SO WE WILL ONLY HAVE POPS AROUND 20 PERCENT THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... IF ANY SHOWERS/THUNDERSTORMS DO DEVELOP THIS AFTERNOON, THEY SHOULD DIMINISH QUICKLY AFTER SUNSET. THERE IS SOME WEAK MID-LEVEL VORTICITY FORECAST OVERNIGHT, BUT THIS MAY ONLY BRING AN INCREASE IN CLOUD COVER OVERNIGHT. THERE IS THE POSSIBILITY FOR SOME LIGHT FOG TO DEVELOP OVERNIGHT FRIDAY INTO SATURDAY MORNING, BUT CONFIDENCE IN OCCURRENCE AND HOW THICK IT WOULD BE IS LOW, SO WE WILL NOT INCLUDE IT AT THIS TIME. OVERNIGHT LOWS WILL REMAIN ABOVE AVERAGE; A BLEND OF MAV/MET MOS WAS TAKEN. && .LONG TERM /SATURDAY THROUGH THURSDAY/... THE RATHER HOT AND HUMID CONDITIONS WILL CONTINUE THIS WEEKEND AS THE HIGH PRESSURE OFF THE EAST COAST CONTINUES TO BRING A SRLY FLOW OF SUMMER-LIKE WARMTH TO THE AREA. TEMPERATURES WILL LIKELY BE IN THE UPPER 80S TO LOW 90S ACROSS THE AREA...LOWER THAN FRI. I WILL NOT EXTEND THE HEAT ADVISORY INTO SAT AT THIS TIME...WITH CONFID IN TEMPERATURES/CLOUD COVER FOR SAT LOW AT THIS POINT. LOW PRESSURE AND A PROGRESSIVE UPPER SHORT WAVE OVER THE UPPER GREAT LAKES SATURDAY WILL MOVE EAST AND ARRIVE ACROSS NEW ENGLAND AND THE MIDDLE ATLANTIC SUNDAY NIGHT AND MONDAY. THIS WILL BRING INCREASED CHANCES FOR SHOWERS AND TSTMS. THE SPC HAS OUTLOOKED THE AREA FOR A SLGT CHC FOR SVR WEATHER ON SUN/SUN NIGHT. THE FRONT WILL SETTLE TO THE SOUTH OF THE AREA MON NIGHT/TUE. THIS WILL ALLOW HIGH PRESSURE TO BUILD IN FROM THE NORTH. TEMPERATURES TUE-THU WILL BE A LITTLE COOLER THAN THE WEEKEND WITH MOSTLY MID OR UPPER 80S...STILL ABOVE NORMAL. HUMIDITY LEVELS SHOULD BE LOWER THAN THEY WILL BE THIS WEEKEND. A CHC FOR A FEW SHOWERS/TSTMS WILL BE ACROSS THE AREA WED AS A WEAK SHORTWAVE MOVES ALONG THE STALLED FRONT TO THE SOUTH AND BRINGS INCREASED MOISTURE TO THE AREA. SLGT CHC/CHC POPS IN THE GRIDS FOR NOW. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. WE ARE STILL ANTICIPATING SOME MVFR FOG TO DEVELOP THIS MORNING. ONCE IT BURNS OFF, VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE DAY. MORNING CIRRUS SHOULD BE REPLACED BY SCT-BKN CLOUDS AROUND 5,000 FEET. THERE IS THE POSSIBILITY OF SOME ISOLATED SHOWERS/THUNDERSTORMS THIS AFTERNOON, BUT THE CONFIDENCE AND COVERAGE IS SMALL ENOUGH NOT TO INCLUDE IN THE TAFS AT THIS TIME. WIND ARE EXPECTED TO REMAIN OUT OF THE SOUTH-SOUTHWEST AND GENERALLY LESS THAN 10 KNOTS. VFR CONDITIONS ARE EXPECTED TO CONTINUE INTO THE EVENING HOURS, BEFORE THE POSSIBILITY OF OVERNIGHT/MORNING MVFR FOG DEVELOPMENT FRIDAY NIGHT INTO SATURDAY MORNING. WINDS WILL LIKELY BECOME LIGHT AND VARIABLE MOST PLACES OVERNIGHT; IF THERE IS ANY WIND IT IS EXPECTED TO BE LIGHT AND OUT OF THE SOUTH-SOUTHEAST. OUTLOOK... SAT AND SAT NIGHT...VFR. SUN THRU MON...VFR MOST OF THE TIME...BUT AREAS OF SHOWERS/TSTMS SUN AFTERNOON AND NIGHT WILL BRING TIMES OF LOWER CIGS/VSBYS. MON THRU TUE...MOSTLY VFR. SCATTERED SHOWERS EARLY MON. && .MARINE... CONDITIONS ON THE WATERS ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS THROUGH FRIDAY NIGHT. WINDS MAY PERIODICALLY GUST AROUND 20 KNOTS, ESPECIALLY EARLY THIS MORNING AND LATER TODAY INTO THE EVENING. OUTLOOK... SUB-SCA CONDITIONS SAT AND SAT NIGHT...BUT THEN AN INCREASING SRLY FLOW WILL BRING SCA CONDITIONS TO THE WATERS FOR SUN INTO MON. AREAS OF SHOWERS/TSTMS ON SUN-MON MAY BRING GUTSY WINDS AND LOCALLY HAZARDOUS CONDITIONS. WINDS AND SEAS WILL SETTLE BACK BELOW SCA CONDITIONS BY TUE. && .RIP CURRENTS... THE MODERATE RISK FOR RIP CURRENTS WAS KEPT FOR NEW JERSEY, AND LOW FOR DELAWARE. NOT MUCH OF A CHANGE IN CONDITIONS FROM YESTERDAY, EXCEPT WE ARE MOVING FURTHER AWAY FROM THE FULL MOON. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR PAZ067>071. NJ...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR NJZ015-017>019. DE...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR DEZ001. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...O`HARA |
| #531412 (Received by flhurricane at: 3:41 AM 03.Aug.2012) AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 341 AM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TODAY WITH POSSIBLE SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN FOR SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... MAIN FOCUS FOR TODAY WILL BE ON THE NEXT...SOMEWHAT STRONGER COLD FRONT WHICH CURRENTLY XTNDS NE-SW FROM CENTRAL QUEBEC DOWN INTO THE ERN GRT LAKES AND IS STILL EXPECTED TO SWING SEWRD ACROSS THE REGION LATER TODAY. SFC CONVERGENCE ALONG AND IN ADVANCE OF THIS BNDRY WILL INTERACT W/ TDS IN THE MID TO UPPER 60S AND A HEALTHY UPPER SHORT WAVE TO TRIGGER THE THREAT OF SOME CONVECTION ACROSS THE AREA BY LATE AM INTO THE AFTN W/ ACTIVITY WINDING DOWN FROM NW-SE LATER THIS AFTN AS DRIER AIR BEGINS TO WORK INTO THE REGION. WHILE SHEAR VALS NOT VERY IMPRESSIVE...SFC BASED CAPES JUMP UP NR 2000 J/KG ACROSS CENTRAL/E CENTRAL AREAS BY ERLY AFTN SO EXPECT THE THREAT OF AN ISOLD STRONG TO SVR TSTM CAN NOT BE RULED OUT AND WILL CONT ENHANCED WORDING... SIMILAR TO THE LAST FEW DYS...ANY ERLY AM FOG/STRATUS TODAY SHOULD LIFT/BURN OFF RATHER QUICKLY THIS AM W/ OUR COASTAL AREAS BEING THE SLOWEST TO IMPROVE. A MORE SWRLY LOW-LEVEL FLOW SHOULD ALLOW HIGH TEMPS TO REACH THE LOWER TO MID 80S N AND MID TO UPPER 80S S AWAY FROM THE COAST... WHILE DRIER AIR OVERSPREADS THE AREA FROM NW-SE TNGT...CLRG SKIES AND LGT WINDS WILL ALLOW FOR SIGNIFICANT COOLING LIKELY ALLOWING TEMPS TO REACH TDS AND INCREASING THE POTENTIAL FOR SOME FOG AGAIN TNGT. IN THESE SCENARIOS IT IS ALWAYS A RACE BTWN THE DRYING AND COOLING AND WHICH FACTOR WINS OUT. FOR NOW...WILL CARRY PATCHY FOG N AND CENTRAL W/ AREAS DOWNEAST AS THESE WILL BE THE LAST TO SEE THE DRIER AIR... EXPECT LOWS TNGT TO BE SIGNIFICANTLY COOLER THAN THE LAST FEW DYS...AT LEAST FOR OUR CENTRAL AND NRN AREAS W/ LOWS RANGING FROM THE LOWER TO MID 50S N TO THE LOWERS 60S S. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... EXPECT THE WEEKEND TO BE MAINLY DRY WITH ABOVE NORMAL TEMPERATURES AS HIGH PRESSURE BUILDS OVER THE REGION. SATURDAY WILL START OUT MOSTLY SUNNY, BUT CLOUDS WILL INCREASE FROM THE SOUTH LATE IN THE DAY AS A WARM FRONT LIFTS NORTHWARD. THIS BOUNDARY WILL MOVE ACROSS THE STATE SATURDAY NIGHT AND MAY PRODUCE A FEW SHOWERS OVER THE HIGHER TERRAIN AS IT DOES SO. MUGGIER AIR WILL SPREAD INTO THE REGION BEHIND THE FRONT WITH A RETURN OF MID 60S DEWPOINTS BY SUNDAY AFTERNOON. A COLD FRONT WILL APPROACH THE REGION FROM QUEBEC SUNDAY AFTERNOON, BUT MOST OF THE PRECIPITATION WILL HOLD OFF UNTIL LATE IN THE DAY, EXCEPT PERHAPS IN FAR WESTERN AREAS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE AFOREMENTIONED COLD FRONT WILL MOVE THROUGH THE STATE LATE SUNDAY NIGHT INTO MONDAY MORNING. THE TIMING OF THE FRONTAL PASSAGE IS NOT OPTIMAL FOR INSTABILITY, THOUGH 0-6 KM SHEAR INCREASES TO AROUND 30 KT JUST AHEAD OF THE FRONT. DOWNEAST AREAS WOULD HAVE THE BEST CHANCES OF SEEING ANY ORGANIZED CONVECTION, AS STORMS WOULD MOST LIKELY BE ELEVATED ACROSS THE NORTH. ALSO OF CONCERN IS INCREASING MOISTURE TRANSPORT AHEAD OF THE FRONT; MODELS ARE INDICATING PWATS OF 2+ INCHES AREAWIDE SUNDAY NIGHT INTO MONDAY MORNING. IN ADDITION, THE WARM CLOUD LAYER LOOKS TO BE DEEP, AROUND 13-14 KFT. THIS MEANS THAT ANY STORMS WOULD BE CAPABLE OF PRODUCING HEAVY RAIN. ONCE THE FRONT GOES BY, HIGH PRESSURE AND DRIER WEATHER RETURNS MONDAY NIGHT AND TUESDAY. THEN ANOTHER COLD FRONT WILL GRADUALLY MOVE SOUTH TUESDAY NIGHT, BECOMING NEARLY STATIONARY NEAR THE SAINT JOHN VALLEY WEDNESDAY BEFORE FINALLY PUSHING SOUTH INTO DOWNEAST MAINE WEDNESDAY NIGHT/THURSDAY. THE LONGER-TERM MODELS ARE SHOWING SOME DIFFERENCES IN TIMING OF THIS FEATURE AND ITS ASSOCIATED PRECIPITATION, SO HAVE STUCK WITH 20-30 POPS FOR MID WEEK. TEMPERATURES WILL BE SEASONABLE THROUGH THE WEEK. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... NEAR TERM: ALL TAF SITES IFR ATTM XCPT KPQI WHICH IS CURRENTLY MVFR. THIS RATHER IRONIC CONSIDERING A TSTM DROPPED SIGNIFICANT RAINFALL ON PQI THU AFTN WHERE MOST OTHER AREAS SO LITTLE OR NO RAINFALL... IN ANY CASE...THINK KPQI WILL JOIN THE REST SHORTLY. IFR CONDS SHOULD THEN PERSIST INTO THE AM HRS SIMILAR TO LAST SEVERAL DAYS W/ KBHB NEAR THE SRN COAST THE SLOWEST TO IMPROVE. DESPITE THE PASSAGE OF A COLD FRONT LATER TODAY AND THE INFLUX OF LOWER TDS...LGT WINDS BEHIND THE FRONT TNGT AND CLR SKIES WILL LEAD TO GOOD COOLING AND WILL LIKELY RESULT IN PATCHY FOG ACROSS THE NRN TAF SITES W/ MORE WDSPRD FOG S... SHORT TERM: VFR IS EXPECTED THROUGH THE WEEKEND, WITH EXCEPTION OF IFR DUE TO PATCHY FOG LATE SATURDAY NIGHT, ESPECIALLY AT THE TERMINALS. A COLD FRONT WILL MOVE ACROSS THE AREA EARLY MONDAY, PRODUCING SHOWERS AND THUNDERSTORMS. WHILE VFR SHOULD PREVAIL THROUGH MIDWEEK, MVFR CONDITIONS ARE POSSIBLE IN ANY PRECIPITATION SUNDAY NIGHT AND MONDAY. && .MARINE... NEAR TERM: WINDS/SEAS SHOULD REMAIN BLO SCA LEVELS THRU TNGT. FOG WILL CONT TO BE AN ISSUE THRU TNGT. SHORT TERM: A SMALL CRAFT ADVISORY MAY BE NEEDED LATE SUNDAY THROUGH MONDAY AS SOUTH WINDS INCREASE AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL BE BORDERLINE /GUSTS AROUND 20 KT/ BUT WAVES LOOK TO REACH 5-6 FT LATE SUNDAY EVENING AND REMAIN SO INTO EARLY MONDAY NIGHT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...KHW |
| #531413 (Received by flhurricane at: 3:41 AM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 329 AM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL APPROACH NEW ENGLAND FROM THE NORTHWEST TODAY, THEN STALL ACROSS THE AREA TONIGHT BEFORE RETURNING NORTH AS A WARM FRONT ON SATURDAY. VERY MUGGY CONDITIONS ARE EXPECTED SATURDAY NIGHT THROUGH SUNDAY NIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION LATE SUNDAY NIGHT OR MONDAY BRINGING WITH IT THE LIKELIHOOD OF SHOWERS AND STORMS. DRIER AIR THEN RETURNS IN THE WAKE OF THE FRONT MONDAY AFTERNOON INTO MIDWEEK. && .NEAR TERM /THROUGH TODAY/... WIDESPREAD FOG WAS FORMING IN HUMID AIRMASS CURRENTLY FOUND ACROSS THE FORECAST AREA. AT 06Z...GOES WATER VAPOR IMAGERY SHOWED SHORT WAVE RACING EASTWARD ACROSS THE EASTERN GREAT LAKES. LOW CLOUD AND FOG BURNS OFF QUICKLY THIS MORNING...WITH SOUTHWEST FLOW AHEAD OF SHORT WAVE AND ASSOCIATED SURFACE COLD FRONT WARMING TEMPERATURES TO AROUND 90F WITH EXCEPTION OF MOUNTAINS...AND ALONG THE MID COAST GIVEN ONSHORE TRAJECTORY. SCATTERED CONVECTION WILL DEVELOP TODAY ACROSS THE REGION WITH FORECAST SOUNDINGS INDICATING CAPES OF 1500 J/KG WITH POTENTIAL FOR A FEW STRONG STORMS WITH WINDS THE PRIMARY CONCERN. HAVE ADDED ENHANCED WORDING FOR STRONG GUSTY WIND AND SMALL HAIL TO PM CONVECTION. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... CONVECTION SHOULD QUICKLY END THIS EVENING WITH LOSS OF HEATING AND UPPER SUPPORT. SURFACE FRONT PRESSES SOUTH THEN STALLS AS HIGH PRESSURE BUILDS BY TO OUR NORTH OVERNIGHT INTO THE FIRST HALF OF SATURDAY. THICKER CLOUDS SPREAD NORTH AND EAST ON SATURDAY AS FRONT BEGINS RETURNING NORTH WITH AN INCREASING CHANCE FOR A SHOWER OR THUNDERSTORM AS WE HEAD THROUGH THE DAY. HIGHS SHOULD BE SEVERAL DEGREES COOLER THEN TODAY GIVEN CLOUDS AND AN ONSHORE FLOW. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... A WARM AND VERY MOIST AIRMASS WILL BE TRANSPORTED NORTHWARD INTO NORTHERN NEW ENGLAND SATURDAY NIGHT THROUGH SUNDAY NIGHT AS THE AREA WILL BE SANDWICHED IN BETWEEN A LARGE HIGH PRESSURE SYSTEM OVER THE WESTERN ATLC AND AN APPROACHING COLD FRONT FROM THE WEST. THIS MAY MEAN A DECENT AMOUNT OF FOG/HAZE AND STRATUS SATURDAY NIGHT AND SUNDAY NIGHT. DEWPOINTS WILL PROBABLY REACH THE 70-75F RANGE SOMETIME SUNDAY AND SUNDAY NIGHT WHICH WILL MAKE IT VERY MUGGY. AS FAR AS POPS GO...LOOKS MAINLY DRY SATURDAY NIGHT AND SUNDAY ALTHOUGH A FEW THUNDERSTORMS MAY START IMPINGING ON THE AREA LATER SUNDAY AFTERNOON...ESPECIALLY IN NH. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS APPEARS TO BE SUNDAY NIGHT AND MONDAY MORNING WHEN THE SHORT WAVE AND COLD FRONTAL FORCING APPROACHES AND SUBSEQUENTLY MOVES ON THROUGH. THESE THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE VERY HEAVY RAINFALL RATES DUE TO THE VERY MOIST COLUMN. CAN/T RULE OUT A FEW STRONG STORMS AS WELL...ESPECIALLY IN TERMS OF WIND DESPITE BEST FORCING APPROACHING AT NIGHT. FRONT LOOKS TO MOVE OFFSHORE MONDAY WITH THE BEST CHANCE OF SHOWERS AND STORMS BEING IN THE MORNING. HOWEVER...WOULDN/T BE SURPRISED TO SEE THE FRONT ACTUALLY COME THROUGH SLOWER THAN CURRENTLY PROGGED...WHICH COULD MEAN HIGHER POPS MONDAY AFTERNOON AND LESSER POPS SUNDAY NIGHT. THEREAFTER...FAIR AND DRIER WEATHER IS EXPECTED INTO MIDWEEK. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH SATURDAY/...IFR/LIFR IN FOG...IMPROVING QUICKLY TO VFR THIS MORNING. SCATTERED AFTERNOON/EVENING MVFR IN SHOWERS AND THUNDERSTORMS. SCT IFR FRI NIGHT IN FOG FOLLOWED BY VFR SAT WITH WIDELY SCATTERED MVFR IN ANY PM SHOWERS OR THUNDERSTORMS. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...LOCAL IFR CONDITIONS POSSIBLE IN STRATUS AND FOG SATURDAY NIGHT THROUGH MONDAY MORNING AS VERY MOIST AIRMASS SITS ACROSS THE AREA. BEST CHANCE OF LOW CIGS AND VSBYS WILL BE AT NIGHT. SHOWERS AND STORMS A GOOD BET SUNDAY NIGHT AND MONDAY MORNING. THEREAFTER...CIGS AND VSBYS LOOK TO IMPROVE. && .MARINE... SHORT TERM /THROUGH SATURDAY...NO FLAGS EXPECTED. HOWEVER...LCL VSBY RESTRICTIONS IN FOG AND HAZE...WITH SCATTERED SHOWERS AND THUNDERSTORMS. LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...COLD FRONT WILL APPROACH THE WATERS FROM THE WEST SUNDAY NIGHT AND CROSS MONDAY. AHEAD OF THE FRONT...A LONG SOUTHERLY FETCH OF WIND MAY BRING SEAS UP TO SCA LEVELS BY LATER SUNDAY AFTERNOON WHICH COULD LAST THROUGH MONDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ ES/MLE |
| #531411 (Received by flhurricane at: 3:41 AM 03.Aug.2012) AFDTBW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAMPA BAY RUSKIN FL 339 AM EDT FRI AUG 3 2012 .SYNOPSIS... EARLY THIS MORNING - WEAK UPPER LEVEL TROUGHING WAS ALOFT THE EAST GULF AND FL...SANDWICHED BETWEEN AN UPPER RIDGE OVER THE SOUTHERN PLAINS AND A SECOND OFF THE EAST U.S. COAST. AT THE SURFACE...A FRONTAL BOUNDARY WAS ACROSS THE SOUTHEASTERN STATES AS ATLANTIC HIGH PRESSURE RIDGED IN ACROSS SOUTH-CENTRAL FL. A TROPICAL WAVE WAS EMBEDDED IN THE SOUTH SIDE OF THE RIDGE AND WAS OVER THE BAHAMAS AND CENTRAL CUBA. TROPICAL STORM ERNESTO WAS NEAR THE NORTHERN WINDWARD ISLANDS...PLEASE SEE NATIONAL HURRICANE CENTER ADVISORIES FOR THE LATEST DETAILS. && .SHORT TERM (TODAY THROUGH SUNDAY)... THE TROUGHINESS ALOFT CONTINUES TO WEAKEN AS IT SLIDES WEST OVER THE GULF AS THE UPPER RIDGE IN THE ATLANTIC BEGIN TO BUILD SOUTHWESTWARD TODAY. THE SURFACE RIDGE AXIS LIFTS UP INTO NORTHERN FL AS THE TROPICAL WAVE APPROACHES THE EAST FL COAST. ON SAT - THE UPPER RIDGE SPREADS OVER FL AS THE SURFACE RIDGE AXIS MOVES INTO SOUTHERN GA WITH THE TROPICAL WAVES CROSSING THE STATE TO THE WEST COAST. FOR SUN - BOTH THE UPPER AND SURFACE RIDGES PIVOT NORTH... TO THE SE U,S. COAST AS THE WAVE SLIDES OUT OVER THE GULF. THE SW AND WEST LOW LEVEL FLOW OF THE PAST FEW DAYS WILL GIVE WAY TO SOUTHEAST AND THEN EASTERLY FLOW AS THE RIDGE AXIS MOVES NORTH AND THE WAVE CROSSES THE AREA. THE PREVAILING LOW LEVEL FLOW THEN BACKS TO SE SUN AS THE RIDGE CONTINUES NORTH AND THE WAVE MOVES AWAY. THE FLOW WILL BE LIGHT ENOUGH FOR SEA BREEZE CIRCULATIONS EACH DAY...HOWEVER THE MORE EASTERLY FLOW SAT WILL KEEP THE SEA BREEZE CLOSE TO THE COAST. THE ATMOSPHERE MOISTENS WITH PWAT VALES RUNNING OVER 2 INCHES THROUGH THE WEEKEND. THE FORECAST WILL BE TYPICAL FOR EARLY AUGUST. THE MOIST AIR MASS...SEA BREEZE CONVERGENCE...AND DAY TIME HEATING WILL RESULT IN ISOLATED BECOMING SCATTERED CONVECTION DURING THE DAY THAT LINGERS INTO THE EVENING. EXCEPT SUN WILL SEE NUMEROUS STORMS OVER COASTAL LOCATIONS DUE TO A MORE ROBUST SEA BREEZE. THIS PATTERN FAVORS A FEW STORMS BECOMING STRONG WITH THE GREATEST THREAT WIND. TEMPERATURES WILL RUN JUST ABOVE NORMAL ALTHOUGH THE HIGHS WILL DIP A DEGREE OR TWO BETWEEN THIS AFTERNOON AND SUN. && .LONG TERM (SUN NIGHT-THURSDAY)... AN U/L RIDGE WILL PERSIST OVER THE ATLANTIC EXTENDING OVER THE SOUTHERN PLAINS THROUGH THE PERIOD. SURFACE HIGH PRESSURE OVER THE WESTERN ATLANTIC WITH THE RIDGE AXIS NORTH OF FLORIDA WILL ALSO PERSIST THROUGH THE PERIOD. EASTERLY BOUNDARY LAYER FLOW WILL HOLD THE WEST COAST SEA BREEZE NEAR THE COAST WITH AFTERNOON BOUNDARY COLLISIONS OVER WEST CENTRAL AND SOUTHWEST FLORIDA. DEEP TROPICAL MOISTURE OVER THE REGION WILL ALLOW NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP MONDAY AND TUESDAY AFTERNOONS. A FEW PULSE SEVERE STORMS ARE POSSIBLE EACH DAY. WILL HAVE TO MONITOR PROGRESS OF TROPICAL STORM ERNESTO NEAR THE WINDWARD ISLANDS AS CURRENT FORECAST TRACKS THE STORM INTO THE WESTERN CARIBBEAN TUESDAY AND WEDNESDAY. SUBSIDENCE AROUND THE PERIPHERY OF THE TROPICAL SYSTEM WILL INCREASE OVER THE FORECAST AREA WEDNESDAY AND THURSDAY WITH DECREASING AREAL COVERAGE OF AFTERNOON THUNDERSTORMS WITH INCREASING DAYTIME TEMPERATURES. DEPENDING ON STRENGTH OF ERNESTO...STRONG SUBSIDENCE AND EASTERLY BOUNDARY LAYER FLOW ACROSS WEST CENTRAL FLORIDA COULD ALLOW AFTERNOON TEMPERATURES TO CLIMB INTO THE MID 90S IN MANY AREAS WEDNESDAY AND THURSDAY. && .AVIATION... VFR CONDITIONS WILL PREVAIL TODAY WITH A FEW SHOWERS AND THUNDERSTORMS DEVELOPING VCNTY TPA/PIE LATE THIS MORNING WITH LCL MVFR CIGS/VSBYS. THUNDERSTORM ACTIVITY WILL PUSH INLAND BY MID AFTERNOON WITH LCL MVFR CIGS AND IFR VSBYS. && .MARINE... SOUTH AND SW WINDS WITH AN AFTERNOON SEA BREEZE FOR TODAY WILL SHIFT TO SE AND EAST FOR THE WEEKEND AND EARLY NEXT WEEK...BUT WITH A SEA BREEZE NEAR THE COAST IN THE AFTERNOONS. WITH WIND SPEEDS OF 10 KT OR LESS THE MAIN MARINE HAZARD WILL BE ISOLATED TO SCATTERED THUNDERSTORMS. && .FIRE WEATHER... A TROPICAL WAVE MOVING ACROSS THE STATE DURING THE WEEKEND WILL KEEP A MOIST AIR MASS IN PLACE THROUGH THE EARLY PART OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 92 77 92 76 / 40 20 40 30 FMY 93 76 92 75 / 40 20 60 30 GIF 94 74 93 74 / 40 20 50 20 SRQ 90 76 91 76 / 30 20 40 30 BKV 93 71 92 72 / 30 20 40 30 SPG 91 79 91 77 / 30 20 40 30 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ |
| #531410 (Received by flhurricane at: 3:29 AM 03.Aug.2012) AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 323 AM EDT Fri Aug 3 2012 .NEAR TERM... [Today] A typical summer day is expected with scattered convection across the area. The PoP distribution was based on sea-breeze climatology, MOS guidance, and the hi-res guidance. The consensus ended up being around 50 percent across most of northwest Florida and southeast Alabama tapering to 40 percent across the northern zones. The severe storm threat appears slightly less than yesterday given a forecast of slightly lower instability and delta thetae values. However, values are still high enough that a pulse severe storm or two cannot be ruled out. Seasonably warm temperatures are expected. && .SHORT TERM... [Tonight through Sunday] Scattered diurnal convection will diminish tonight. On Saturday and Sunday, differences start to emerge between the NAM and the GFS. The NAM moves a weak tropical wave through the area on Saturday, and the GFS holds off until Sunday. Both models have an upper level shortwave dropping south and affecting the western zones on Saturday, so the likely PoPs from the previous forecast were maintained across that area. Elsewhere, scattered convection is expected on Saturday. PoPs were increased to likely on Sunday across northwest Florida in favor of the GFS with the expectation that a weak tropical wave will move westward through the area with increased moisture late in the day. This has some support from the 00z ECMWF as well. Seasonably warm temperatures are expected. && .LONG TERM... [Sunday night through next Friday] Weak tropical wave axis is forecast to pass across the forecast area late Sunday into Monday. With the southeasterly flow in the wake of the wave and a weakness aloft between subtropical ridges to the east and west, expect deep layer moisture to remain elevated on Monday with at least scattered showers and thunderstorms across the entire forecast area. The onshore low-level flow trajectory is expected to continue through at least Thursday, keeping PoPs elevated and temperatures near seasonal norms. && .AVIATION... [Beginning 06Z Friday] Typical summertime pattern is expected today, with a few areas of IFR cigs/vsby this morning, followed by scattered thunderstorms this afternoon and evening. Best chances for TSRA this afternoon appear to be at southern terminals, where tempos are included in the forecast. && .MARINE... A ridge of high pressure south of the area is expected to keep light onshore winds through today. A tropical wave will then move west across the area late in the weekend swinging winds around to the east and southeast. A trough will establish itself north of the waters early next week with a ridge to the south. This will bring a return to light onshore winds. && .FIRE WEATHER... Afternoon Relative Humidity levels are expected to remain above critical thresholds for the next week, so red flag conditions are not expected. && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ |
| #531409 (Received by flhurricane at: 3:29 AM 03.Aug.2012) AFDMLB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 320 AM EDT FRI AUG 3 2012 .DISCUSSION... ...INCREASING RAIN CHANCES INTO THE WEEKEND WITH PASSAGE OF A TROPICAL WAVE... TODAY/TONIGHT...SURFACE ATLANTIC RIDGE AXIS WILL LIFT GRADUALLY NORTHWARD ACROSS CENTRAL FLORIDA TODAY INTO TONIGHT AS A TROPICAL WAVE OVER THE BAHAMAS REGION APPROACHES THE SOUTHERN FLORIDA PENINSULA. WEAK LOW LEVEL WINDS WILL BECOME E/SE AND ALLOW FOR EAST COAST SEA BREEZE DEVELOPMENT ALONG THE ENTIRE COAST BY EARLY AFTERNOON. MOISTURE WILL INCREASE SLIGHTLY AHEAD OF THE WAVE WITH PW VALUES UP TO AROUND 1.7 INCHES. THIS SHOULD BE SUFFICIENT FOR ISOLATED TO SCATTERED SHOWERS AND STORMS TO DEVELOP ALONG THE SEA BREEZE WITH GREATEST RAIN CHANCES OVER THE INTERIOR AND TREASURE COAST INTO THE AFTERNOON. LINGERING MID LEVEL DRY AIR AND COOLER TEMPS ALOFT WILL KEEP A CHANCE FOR A FEW STRONGER STORMS TO DEVELOP...ESPECIALLY ALONG ANY BOUNDARY COLLISIONS. MAX TEMPS WILL REACH AROUND 90 DEGREES ALONG THE COAST WITH LOW TO MID 90S FARTHER INLAND. CONVECTION WILL WIND DOWN INTO THE EARLY EVENING OVER THE INTERIOR. HOWEVER AS THE TROPICAL WAVE APPROACHES THE SOUTHEAST FLORIDA COAST...MOISTURE AND ONSHORE FLOW WILL INCREASE AND KEEP A CHANCE FOR ONSHORE MOVING SHOWERS AND STORMS...ESPECIALLY ALONG THE TREASURE COAST AFTER MIDNIGHT. SKIES WILL RANGE FROM PARTLY CLOUDY TO MOSTLY CLEAR TONIGHT WITH LOWS IN THE LOW TO MID 70S. THIS WEEKEND...WEAK T-WAVE WILL ROUND THE WESTERN PERIPHERY OF THE ATLC HIGH PRES RIDGE...RIDING NORTHWARD INTO THE WEAKNESS OVER FL. THIS WILL BRING WITH IT AN INCREASE IN MEAN PWAT AND POPS IN A MORE CONVERGENT SE WIND FLOW. PAINTED SLIGHTLY HIGHER POPS (60-65 PERCENT AREAWIDE) SATURDAY AS MOISTURE SHOULD BE HIGHER AND THE FLOW NOT QUITE AS BACKED AS IT WILL BE SUN...WHEN POPS WILL BE 50 COAST AND 60 INLAND. MAX TEMPS FAIRLY CLOSE TO CLIMO NORMS...WITH SULTRY MINS A FEW DEGREES ABOVE NORMAL OUTSIDE OF AREAS THAT RECEIVE DECENT AMOUNT OF PRECIP. MON-FRI...BEHIND THE WEAK WAVE...FAIRLY DECENT STRENGTH DEEP LAYER MEAN RIDGING WILL BUILD BACK WWD FROM THE ATLC INTO FL. THE DEEP LAYER EASTERLIES SHOULD KEEP T.C. "ERNESTO" WILL SOUTH OF FL AS IT TRAVERSES WWD THROUGH THE CARRIBEAN. RELATIVELY DRIER EASTERLY FLOW WILL SPELL LOWER POPS...AS HIGHER RAIN CHANCES SHIFT TO THE WRN SIDE OF THE PENINSULA. RAN WITH POP NUMBERS NEAR NORMAL MON-TUE...THEN A LITTLE BELOW NORMAL FOR EARLY AUGUST FROM MID WEEK ONWARD. MAX TEMPS NEAR CLIMO WITH MINS A LITTLE ABOVE OWING TO LIGHT NOCTURNAL ONSHORE WINDS. && .AVIATION...VFR CONDS EXPECTED THROUGH THE MORNING. EAST COAST SEA BREEZE WILL DEVELOP BY THE EARLY AFT AND MOVE INLAND THROUGH THE REST OF THE DAY. ISO/SCT SHRA/TSRA WILL FORM ALONG AND AHEAD OF THIS BOUNDARY...PRODUCING TEMPO IFR/MVFR CONDS. BEST CHANCES FOR CONVECTION WILL BE OVER THE INTERIOR LATER IN THE AFTERNOON. WILL MAINTAIN VCTS IN TAFS FOR EXPECTED TIMING OF STORMS. ONSHORE MOVING SHOWERS AND STORMS WILL CONTINUE TO BE POSSIBLE... ESPECIALLY SOUTH OF KMLB AFT 04Z TONIGHT WITH APPROACH OF A TROPICAL WAVE. && TODAY-TONIGHT...SFC RIDGE AXIS WILL LIFT SLOWLY NORTHWARD OVER THE WATERS TODAY INTO TONIGHT AS A TROPICAL WAVE APPROACHES THE SE COAST OF FLORIDA. SOUTHERLY WINDS EARLY THIS MORNING WILL WEAKEN AND BECOME EAST/SOUTHEAST INTO TODAY...REMAINING AROUND 5-10 KNOTS. WINDS WILL INCREASE UP TO 10-15 KNOTS TONIGHT AS WAVE APPROACHES THE COASTAL WATERS. SEAS TO REMAIN AROUND 2-3 FEET. SAT-TUE...MAIN MARINE CONCERN WILL BE HIGHER COVERAGE OF SHOWERS AND STORMS OVER THE ADJACENT ATLC THIS WEEKEND. FLOW WILL BACK MORE TO ONSHORE WITH SLIGHTLY HIGHER WINDS/SEAS INDICATED FOR SAT THROUGH EARLY SUNDAY. OTHERWISE...A LITTLE SLACKENING OF THE ONSHORE FLOW FROM LATE SUN ONWARD WITH SEAS 2-3FT THROUGH EARLY NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... DAB 91 75 91 77 / 20 20 60 30 MCO 94 74 93 75 / 30 20 60 30 MLB 90 76 89 77 / 20 20 60 40 VRB 90 76 89 76 / 30 20 60 40 LEE 94 75 93 76 / 30 20 60 30 SFB 94 76 93 76 / 30 20 60 30 ORL 94 76 93 77 / 30 20 60 30 FPR 90 75 89 76 / 30 20 60 40 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ |
| #531408 (Received by flhurricane at: 3:24 AM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 318 AM EDT FRI AUG 3 2012 .SYNOPSIS... WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TODAY AS HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 315 AM FRIDAY...WEAK UPPER LEVEL LOW TO THE SOUTH WILL GRADUALLY LIFT OUT TO THE NORTH TODAY. THE 500 MB ANALYSIS SHOWED -10 DEG C AT 00Z AND GIVEN THIS RATHER COLD AIR ALOFT AND SOME MODERATE SURFACE-BASED INSTABILITY THIS AFTERNOON WITH CAPES IN THE 1000 TO 1500 J/KG RANGE AND LI`S OF -4 TO -6...WILL FORECAST ISOLATED TSTMS ALONG INLAND AREAS ASSOCIATED WITH THE SEA BREEZE. MAX TEMPERATURES AREA-WIDE SHOULD BE IN THE UPPER 80S TO LOWER 90S. && .SHORT TERM /TONIGHT/... AS OF 315 AM FRIDAY...THE UPPER AIR PATTERN STARTS TO CHANGE BY LATER TONIGHT AS H5 RIDGE NEAR BERMUDA STARTS TO BUILD WEST WITH STEADY HEIGHT RISES INDICATED OVERNIGHT. ANY CONVECTION SHOULD SHIFT FROM THE LAND TO THE COASTAL AREAS AND OFFSHORE WATERS AND WILL HAVE A SLIGHT CHANCE OVERNIGHT. MINIMUM TEMPERATURES TONIGHT GENERALLY FROM 73 TO 78 DEGREES ACROSS THE REGION. && .LONG TERM /SATURDAY THROUGH THURSDAY/... AS OF 245 AM FRI...CONTINUED WITH LITTLE CHANGES TO THE FORECAST OR FORECAST REASONING THROUGH THE LONG TERM. HIGH PRESSURE ALOFT WILL CONTINUE TO EXTEND INTO THE AREA FROM THE WESTERN ATLANTIC THROUGH THE WEEKEND. THE BERMUDA HIGH ALSO STRENGTHENS OFFSHORE ALLOWING MOIST SOUTHERLY FLOW TO CONTINUE THROUGH THE EXTENDED. EXPECT ISOLATED TO SCATTERED DIURNAL CONVECTION INLAND AND ALONG THE SEA BREEZE BOUNDARY THROUGH THE WEEKEND. LOW LEVEL THICKNESSES WILL PERSIST AT 1415-1420 METERS...YIELDING TEMPS NEAR CLIMATOLOGY WITH HIGHS IN THE LOW/MID 90S INLAND TO 80S ALONG THE COAST. A FRONTAL BOUNDARY IS PROGGED TO APPROACH THE AREA FROM THE NORTHWEST MON WITH MOIST SOUTHWESTERLY FLOW AND INCREASING LOW LEVEL SHEAR AHEAD OF A ROBUST MID LEVEL SHORTWAVE. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE MON AFTERNOON/EVENING WITH PWATS AGAIN BUILDING ABOVE 2 INCHES. 12Z OPERATIONAL ECMWF AND GFS INDICATE THE FRONT WILL STALL JUST WEST OF THE REGION ACROSS THE CENTRAL PIEDMONT AND MID ATLANTIC STATES LATE MON THROUGH THURS WHILE AN UPPER TROUGH BECOME RE-ESTABLISHED ACROSS THE EASTERN CONUS. 00Z/12Z ECMWF SUGGEST A WEAK SURFACE LOW WILL FORM ALONG THE FRONT TUES NIGHT AND PUSH NE OFF THE MID ATLANTIC COAST WED INTO WED NIGHT. WILL MAINTAIN CHANCE POPS TUES THROUGH THURS WITH THE UPPER TROUGH AND STALLED SURFACE FRONT CONTINUING ACROSS THE REGION WHILE WEAK SHORTWAVES MOVE THROUGH THE FLOW ALOFT. LOW LEVEL THICKNESSES WILL REMAIN AROUND 1415 METERS MON THROUGH THURS HOWEVER GREATER CLOUD COVER AND PRECIP MAY MODERATE TEMPS FROM REACHING ABOVE THE 90 DEGREE MARK EACH DAY. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 06Z SATURDAY/... AS OF 105 AM FRIDAY...GIVEN NEARLY CALM WINDS AND MOSTLY CLEAR SKIES...IFR CONDITIONS IN FOG AND STRATUS ARE POSSIBLE LATER TONIGHT IN FOG. ANY FOG SHOULD DISSIPATE QUICKLY AFTER SUNRISE WITH VFR CONDITIONS EXPECTED THROUGH FRIDAY. LONG TERM /SATURDAY THROUGH TUESDAY/ AS OF 245 AM FRI...PREDOMINANT VFR AVIATION CONDITIONS EXPECTED THROUGH THE EXTENDED. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN DIURNAL CONVECTION EACH DAY. SOUTHWESTERLY SURFACE FLOW WILL PERSIST INTO EARLY NEXT WEEK WITH HIGH PRESSURE ANCHORED OFFSHORE. A FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST MON NIGHT INTO TUES WITH SHOWERS AND THUNDERSTORMS EXPECTED AHEAD OF AND ALONG THE BOUNDARY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 315 AM FRIDAY...A LIGHT S/SW WINDS AT 10 KNOTS OR LESS WITH A GENTLE SOUTHEAST SWELL COMPONENT WILL MAKE FOR ANOTHER 24 HOURS OF BENIGN MARINE CONDITIONS TODAY AND TONIGHT. WAVEWATCH AND LOCAL SWAN IN PRETTY GOOD AGREEMENT SHOWING 2 TO 3 FOOT SEAS TODAY AND TONIGHT AND WINDS WILL GENERALLY NOT EXCEED ABOUT 10 OR 12 KNOTS FROM THE SOUTH TO SOUTHWEST THROUGH EARLY SATURDAY MORNING. LONG TERM /SATURDAY THROUGH TUESDAY/ AS OF 245 AM FRI...GOOD BOATING CONDITIONS EXPECTED SAT AND SUN WITH THE BERMUDA HIGH STRENGTHENING OVER THE WESTERN ATLANTIC BRINGING SLY WINDS ACROSS THE WATERS. SPEEDS WILL RANGE GENERALLY 10-15 KNOTS WITH SEAS 2 TO 3 FT. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THE WEEKEND AS WELL. GRADIENT BEGINS TO TIGHTEN LATE SUN AND MON AS FRONTAL SYSTEM APPROACHES FROM THE NW AND EXPECT WINDS TO INCREASE TO AROUND 15-20 KT...MAINLY ACROSS THE NORTHERN AND CENTRAL WATERS. SWAN/WAVEWATCH HAVE BACKED OFF SLIGHTLY WITH SEAS EARLY NEXT WEEK...NOW ONLY BUILDING ABOUT A FOOT OR SO...UP TO 4 FT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ |
| #531407 (Received by flhurricane at: 3:09 AM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 257 AM EDT FRI AUG 3 2012 .SYNOPSIS... VERY WARM AND HUMID WEATHER WILL PERSIST THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND THUNDERSTORMS...BUT SHOWERS AND THUNDERSTORMS ARE MORE LIKELY MONDAY WHEN A COLD FRONT CROSSES SOUTHERN NEW ENGLAND. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST BY THURSDAY. && .NEAR TERM /THROUGH TODAY/... 3 AM UPDATE... LOW CLOUDS REMAIN LOCKED IN AROUND CAPE COD AND ISLANDS...ALTHOUGH IR SATELLITE DOES SHOW SOME HOLES AROUND NANTUCKET. THIS CLOUD BANK WILL NOT MAKE MUCH MORE PROGRESS INLAND THROUGH SUNRISE BASED UPON SATELLITE TRENDS...PROBABLY ONTO S COASTAL MA BUT NOT MUCH FARTHER THAN THAT. ONCE SUN COMES UP THIS DECK OF LOW CLOUDS WILL RETREAT OFFSHORE. MAIN CONCERN TODAY DEALS WITH POTENTIAL FOR SHOWERS AND THUNDERSTORMS. 00Z MODELS SHOW PLENTY OF INSTABILITY WITH SURFACE BASED CAPES 1500-2500 J/KG AND MARGINAL MID LEVEL LAPSE RATES NEAR 6C/KM. HOWEVER WINDS ALOFT REMAIN RATHER WEAK WHICH LEADS TO POOR 0-6KM SHEAR. APPROACHING COLD FRONT IS EXPECTED TO WEAKEN AS IT REACHES SOUTHERN NEW ENGLAND THIS AFTERNOON...BUT SHOULD BECOME FOCUS FOR SCATTERED SHOWERS/STORMS TO DEVELOP. MAIN THREAT WILL BE LOCALLY HEAVY RAIN...BUT PER SPC DAY 1 OUTLOOK THERE IS ALSO A LOW PROBABILITY OF STRONG WIND GUSTS AND HAIL IF HIGHER CORES CAN MANAGE TO DEVELOP. PROBABLY LOOKING AT PULSE STORMS WHICH MAY ATTEMPT TO FORM INTO BOWING SEGMENTS. EXPECT INITIAL ACTIVITY TO REACH SW NH AND NW MA LATER THIS MORNING /HRRR LOOKS REASONABLE WITH 14Z-15Z ONSET/...BUT EXPECT MOST OF STORMS WILL OCCUR BETWEEN NOON AND 5 PM ALONG MASS PIKE CORRIDOR AND INTO HARTFORD AND PROVIDENCE. NOT CONFIDENT STORMS WILL FIRE CLOSER TO S COAST GIVEN STABILIZING SW FLOW...BUT WITH FAIRLY HIGH CAPE STORMS CANNOT BE RULED OUT DOWN THERE EITHER. 850 MB TEMPERATURES ARE PROGGED TO REACH 17-18C WHICH WOULD YIELD HIGHS IN 90S WITH FULL SUN. NAM MOS HAS LOW TO MID 90S ACROSS MUCH OF AREA WHICH LOOKS A LITTLE HIGH GIVEN SOME EXPECTED CLOUD COVER... SO LEANED MORE TOWARD GFS MOS TODAY WITH MID 80S TO MID 90S. DEWPOINTS NEAR 70 /ESPECIALLY S OF MASS PIKE/ YIELDS HEAT INDICES IN MID TO UPPER 90S WHICH IS BELOW HEAT ADVISORY CRITERIA. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... ISOLATED SHOWERS/STORMS WILL BE SLOW TO DIMINISH THIS EVENING DESPITE LOSS OF DAYTIME HEATING DUE TO PLENTY OF LOW LEVEL MOISTURE AND WEAK CONVERGENCE ALONG DISSIPATING FRONT. SHOULD SEE ANOTHER NIGHT OF LOW CLOUDS AND PATCHY FOG...MAINLY NEAR S COAST. USED A BLEND OF GFS/NAM MOS WHICH ARE CLOSE TO EACH OTHER. COLD FRONT WILL HAVE WASHED OUT OVER SOUTHERN NEW ENGLAND SAT...BUT SHOULD STILL BECOME A FOCUS FOR SCATTERED SHOWERS AND STORMS ONCE AGAIN. MODELS INDICATE THIS MAY BEGIN A BIT EARLIER THAN TODAY...BY MID TO LATE MORNING...AS SOME WEAKENING UPSTREAM CONVECTION COMES INTO PLAY. LOOKS LIKE ANOTHER DAY WITH POTENTIALLY HIGH CAPE AND WEAK SHEAR BUT WITH BETTER MID LEVEL LAPSE RATES...SO POTENTIAL FOR GUSTY WINDS AND HAIL MAY BE A LITTLE HIGHER THAN TODAY. LEANED CLOSER TO GFS MOS FOR HIGHS GIVEN EXPECTED CLOUD COVER AND A POSSIBLE EARLIER START TO CONVECTION...IN 80S TO AROUND 90. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... * QUIET AND MILD SAT NGT * RAIN BECOMING WIDESPREAD SUN-MON ALONG AND AHEAD OF A COLD FRNT * HEAVY RAIN EXPECTED...FLOODING IS A DISTINCT POSSIBILITY * ENERGY OFFSHORE AROUND TUE MORN...QUIET WX EXPECTED INTO WED * ANOTHER DISTURBANCE PSBL INTO THE END OF THE WEEK MODEL DIAGNOSIS... MDL SOLNS ARE STILL TRENDING WITH A PERSISTENT GENERAL PATTERN OF A DEEP POLAR VORTEX ACROSS THE NRN HUDSON BAY RGN WITH A SERIES OF DISTURBANCES ROTATING AROUND THE PERIMETER AND ACROSS THE NERN CONUS. MEANWHILE STRONG RIDGING PERSISTS THRU THE ATLANTIC AND WRN ROCKIES. THE MID-HIGH LATITUDE BLOCKING PATTERN KEEPS AN ACTIVE PATTERN FOR THE FCST. BUT WATCHING A PSBL EWD SHIFT IN THE PATTERN OVER THE NWRN CONUS BY THE FOLLOWING WEEK AS A SERIES OF DISTURBANCES PROMOTE DEEP TROUGHING THRU THE GULF OF ALASKA...CONSEQUENTIALLY SHIFTING THE MAIN RIDGE OF HIGH PRES ACROSS THE CENTRAL CONUS TOWARDS THE ERN CONUS. OVERALL...WHILE MDL SOLN CONTINUITY HAS PERSISTED INTO THE BEGINNING OF NEXT WEEK WITH THE 02/12Z GUIDANCE...THEREAFTER IT HAS REMAINED UNCERTAIN DUE TO RUN TO RUN VARIABILITY OF TIMING/PHASING OF KEY FEATURES ACROSS THE MID-HIGH LATITUDES. HPC HAS EMPHASIZED A MORE CONSENSUS APPROACH WITH EQUAL WEIGHTING OF DETERMINISTIC AND ENSEMBLE MDL SOLNS. OF GREATER CERTAINTY...MDL SOLNS IN BETTER AGREEMENT OF ACTIVITY INITIATING SUNDAY AND CONTINUING SUNDAY NIGHT INTO MONDAY WITH THE APPROACH OF A SFC COLD FRNT. AM STILL CONCERNED OVER THE PROLONGED PERIOD OF SUB-TROPICAL MOISTURE FETCH NEWD ACROSS NEW ENGLAND AHEAD OF THE COLD FRNT /PWATS AROUND 2.25 IN/ WARRANTING THE POSSIBILITY OF FLOOD WATCHES. BETTER AGREEMENT OF THE COLD FRNT AND ATTENDANT ENERGY OFFSHORE BY TUE MORN. AND FINALLY...THERE IS ALSO SLIGHTLY BETTER CONSENSUS OF A FOLLOW UP DISTURBANCE BY THE END OF THE WEEK. SATURDAY NIGHT... CONVECTIVE ELEMENTS DURING THE DAY DIMINISH AS WEAK HIGH PRES TAKES CONTROL. SLY FLOW ENHANCING THRU THE EVNG IN RESPONSE TO THE APPROACHING SYNOPTIC SYS ACROSS THE GRT LKS BY SUNDAY MORN. WILL SEE A SURGE OF LOW 70 DEWPOINTS TOWARDS THE S SHORE OF NEW ENGLAND. CANT RULE OUT THE DEVELOPMENT OF LOW STRATUS AND FOG FOR SHORELINE COMMUNITIES. SHOULD BE A MILD NIGHT WITH MINS RANGING FROM THE UPR 60S TO LOW 70S /MID 70S PSBL/. SUNDAY THROUGH MONDAY... THE COMBINATION OF ENHANCED LOW-MID LVL FLOW OF SUB-TROPICAL AIR FROM THE SERN CONUS ON SUNDAY CONVERGENT ALONG A PSBL PRE-FRONTAL TROUGH...AND DESTABILIZATION OF THE LOCAL BOUNDARY LYR...WARRANTS CHC POPS FOR SUNDAY INTO SUNDAY NGT. ADVERTISED PWATS DURING THIS TIMEFRAME ARE AROUND 2 INCHES WITH MDL SOUNDINGS INDICATED A FAIRLY MOIST ADIABATIC PROFILE WITH THIN ELONGATED CAPE THRU THE ATMOS COLUMN OF 500-1000 J/KG. PRESENT THINKING IS FOR SHOWERS AND THUNDERSTORMS TO INCREASE IN AERIAL COVERAGE THRU THE DAY ACROSS THE MID-ATLANTIC NEWD INTO NEW ENGLAND. BEST POP CHCS WILL BE OVER WRN AND CENTRAL NEW ENGLAND. WHILE STORMS /LIKELY PULSY IN NATURE/ ARE EXPECTED TO BE SUB-SEVERE...HEAVY RAIN WILL BE A THREAT. ACTIVITY SHOULD CONTINUE SUNDAY NIGHT INTO MONDAY ALONG AND AHEAD OF THE COLD FRNT FCST TO SLIDE THRU THE RGN AND OFFSHORE BY TUE MORN. FRONTOGENETICAL FORCING OF CONTINUED LOW-MID LVL SWLY ADVECTION OF SUB-TROPICAL AIR SHOULD LEND TO LIKELY POPS FOR SHOWERS AND THUNDERSTORMS. SOME UNCERTAINTY AS TO WHETHER CLOUDS WILL BREAK ALLOWING FOR DESTABILIZATION OF THE BOUNDARY LYR ON MONDAY. NEVERTHELESS THE POSSIBILITY FOR ELEVATED CONVECTION EXISTS WITH CAPE VALUES HOVERING AROUND 500-1000 J/KG WITHIN A VERY MOIST ADIABATIC ENVIRONMENT. EXPECTED EMBEDDED HEAVIER RAINS WITH PULSE TYPE CONVECTION. PWATS ADVERTISED AROUND 2.25 INCHES AHEAD OF THE COLD FRNT WARRANT THE POSSIBILITY OF FLOODING. TUESDAY AND TUESDAY NIGHT... LOOKS TO REMAIN DRY WITH WEAK HIGH PRES ACROSS THE RGN IN WAKE OF MONDAYS DISTURBANCE SITTING OFFSHORE OF NEW ENGLAND. SLIGHTLY COOLER AND DRIER AIR BUILDS INTO THE RGN /H85 TEMPS AROUND +14C/. LGT AND VRB W/SWLY FLOW. WEDNESDAY THROUGH FRIDAY... A SECOND DISTURBANCE WITH ATTENDANT COLD FRNT IS EXPECTED TO SLIDE THRU THE RGN...USURPING ONCE AGAIN BETTER SUB-TROPICAL MOISTURE FROM THE SERN CONUS. MDL SOLNS VARY WITH OUTCOMES BASED ON EVOLUTION OF MID-LYR FEATURES THRU THE MID-HIGH LATITUDES. AM SOMEWHAT HESITANT TO ACCEPT THE 03/0Z GFS SOLN...RATHER AM MORE FAVORABLE TO THE SIMILAR TRENDS PER 03/0Z CANADIAN AND 02/12Z ECMWF. WILL HINT AT PRECIP FOR WED-THURS...WITH IMPROVEMENT FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND WITH ACTIVITY SHUNTED OFFSHORE BY HIGH PRES BUILDING S OUT OF CANADA. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT TAF CONFIDENCE...MODERATE. IFR/LIFR AROUND CAPE COD AND ISLANDS NOT EXPECTED TO MAKE MUCH MORE PROGRESS INLAND...PROBABLY ONLY TO S COASTAL MA. IFR WILL BE MORE LOCALIZED ACROSS INTERIOR WHERE PATCHY FOG FORMS...MAINLY INTERIOR SE MA. SHOULD SEE RAPID IMPROVEMENT TO VFR 10Z-13Z AREA WIDE. SCT TSTMS EXPECTED TO DEVELOP AFTER 17Z...MAINLY ALONG BDL-ORH-BOS CORRIDOR AND N WHICH WILL BRING LOCAL IFR IN HEAVY RAIN. STORMS SHOULD DIMINISH AFTER 21Z. RETURN OF PATCHY FOG/LOW CLOUDS THIS EVENING AROUND CAPE COD AND ISLANDS. OTHERWISE VFR TONIGHT. ANOTHER ROUND OF SCT TSTMS EXPECTED SAT. KBOS TAF...HIGH CONFIDENCE. LOW CLOUDS/FOG EXPECTED TO REMAIN S OF TERMINAL THROUGH DAYBREAK. INCLUDED VCTS GROUP FOR TIMING OF TSTMS. KBDL TAF...MODERATE CONFIDENCE. COULD SEE BRIEF MVFR IN FOG BEFORE DAYBREAK. INCLUDED VCTS GROUP FOR TIMING OF TSTMS. OUTLOOK...SUNDAY THROUGH TUESDAY... SATURDAY NIGHT...MODERATE TO HIGH CONFIDENCE. EXPECTING FOG AND LOW STRATUS /IFR-LIFR IMPACTS/ ALONG THE S COAST ADVECTED NWD BY INCREASING SLY FLOW. THRU THE INTERIOR...MID-UPR LVL CLOUDS ON THE INCREASE...PREVAILING VFR. SUNDAY THROUGH MONDAY...MODERATE CONFIDENCE. INCREASING AERIAL EXTENT OF SHRA/TSRA ALONG AND AHEAD OF AN APPROACHING COLD FRNT FROM THE W. SHRA/TSRA MAY BE HEAVY AT TIMES... ESPECIALLY MONDAY AS THE COLD FRNT TRAVERSES THE TERMINALS... PUSHING OFFSHORE BY TUE MORN. PREVAILING MVFR-VFR...TEMPO IFR VSBY IMPACTS WITH +SHRA/+TSRA. ESPECIALLY DURING EVNG PDS...EXPECTING FOG AND LOW STRATUS ALONG THE S COAST WITH IFR-LIFR IMPACTS. STRONG SLY FLOW WITH GUSTS UP TO 25 KTS THRU THE ENTIRE PD. TUESDAY...MODERATE CONFIDENCE. WLY WIND FLOW. PREVAIL VFR. LESSER CHCS FOR FOG AND LOW STRATUS. && .MARINE... FAIRLY CONFIDENT WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH SAT. SW WINDS GUST TO 20KT ALONG S COAST THIS AFTERNOON...WHICH INCLUDES BUZZARDS BAY AND VINEYARD SOUND...BUT PROBABILITY OF REACHING 25KT IS LOW. SEAS WILL CONTINUE TO BUILD SLOWLY ON S COASTAL WATERS DUE TO PERSISTENT SW FLOW BUT ARE NOT EXPECTED TO REACH 5 FT. MAIN HAZARDS INCLUDE SCATTERED TSTMS THIS AFTERNOON AND SAT AFTERNOON...MAINLY FROM NARRAGANSETT BAY TO BOSTON HARBOR AND MERRIMACK RIVER...AND PATCHY DENSE FOG ON S COASTAL WATERS LATE TONIGHT AND SAT MORNING. OUTLOOK...SUNDAY THROUGH TUESDAY... INCREASING SLY FLOW ALONG AND AHEAD OF AN APPROACHING COLD FRNT WILL RESULT IN SWELL AND HIGH SEAS ACROSS THE S WATERS /WAVE HEIGHTS OF AROUND 7 FT FOR THE OUTER WATERS...WITH 5-7 FT FOR THE INNER WATERS ALONG THE S COAST/. E WATERS WILL GRADUALLY RISE AS WELL. GUSTS UP TO 25 KTS CAN BE EXPECTED BEGINNING LATE SUNDAY THROUGH TUE BY WHICH POINT THE COLD FRNT WILL HAVE SHUNTED E...TRANSITIONING OUT TO SEA. AERIAL EXTENT OF SHOWERS AND THUNDERSTORMS WILL INCREASE THRU THE PD...BEGINNING SUNDAY. SOME OF THESE STORMS...ESPECIALLY ALONG AND AHEAD OF THE COLD FRNT...WILL BE ASSOC WITH HEAVY RAIN AND REDUCED VSBYS. RAINS AND ACTIVITY SHOULD BE E OF THE WATERS BY LATE MORN INTO MIDDAY TUE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR MAZ004>006-009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...SIPPRELL/JWD |
| #531406 (Received by flhurricane at: 2:12 AM 03.Aug.2012) AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 830 PM HST THU AUG 2 2012 .SYNOPSIS... MODERATE TRADE WINDS WILL PREVAIL AT LEAST THROUGH EARLY NEXT WEEK. CONDITIONS WILL REMAIN ON THE DRY SIDE OF AVERAGE...WITH MOST SHOWERS LIMITED TO WINDWARD SLOPES...OR TO LEE SLOPES OF THE BIG ISLAND IN THE AFTERNOON. && .DISCUSSION... OBSERVATIONS AROUND THE MAIN HAWAIIAN ISLANDS REPORTED LIGHT TO MODERATE TRADE WINDS. PRESSURE TRENDS SUPPORTED THIS IMPRESSION... AND SUGGESTED LITTLE OR NO CHANGE THROUGH THE SHORT RUN. ALTHOUGH THE AIR MASS IN PLACE OVER THE STATE HELD MOISTURE AT OR ABOVE CLIMATOLOGY FOR THIS TYPICALLY HUMID MONTH...A SOLID AND LOW INVERSION SUBSTANTIALLY SUPPRESSED SHOWER DEVELOPMENT. ACTUALLY... SATELLITE ESTIMATES SHOWED A STREAM OF QUITE DRY AIR TO THE SOUTHEAST OF THE BIG ISLAND...BUT THE TRADE WINDS SHOULD KEEP THE TRAJECTORY OF THAT AIR MASS TO THE SOUTH OF THE STATE THROUGH THE SHORT RUN...AND MODEL CONSENSUS PREDICTS LITTLE FURTHER CHANGE THROUGH THE MIDDLE OF NEXT WEEK. ALOFT...STRONG RIDGING PREVAILED IMMEDIATELY OVER THE ISLANDS...BUT FAIRLY DEEP TROUGHING TO THE NORTH. GUIDANCE SUGGESTS SOME WEAKENING OF BOTH THROUGH THE FORECAST PERIOD...BUT LITTLE CHANGE IN THE OVERALL PATTERN. THUS...SUBSIDENCE THROUGH A DEEP LAYER SHOULD CONTINUE TO SUPPORT A LOWERED AND STRENGTHENED INVERSION. A NUMBER OF MODELS PREDICTED A LOW OR TROUGH TO DEVELOP SOUTHEAST OF MIDWAY ISLAND ON OR AROUND SATURDAY. CONDITIONS THERE WILL NOT BE WELL SUITED FOR THE DEVELOPMENT OF A TROPICAL CYCLONE AS SUCH...BUT IF THE LOW DEEPENS AS MUCH AS GUIDANCE PREDICTS...THEN IT WILL PRODUCE LARGE AREAS OF LOCALLY STRONG WINDS AND HEAVY RAIN ANYWAY. FOR NOW...THIS FEATURE IS NOT EXPECTED TO APPROACH...OR EVEN MOVE TOWARD...THE MAIN HAWAIIAN ISLANDS. HOWEVER...THE DIRECTION AND SPEED OF THE TRADE WINDS LIKELY WILL BE AFFECTED SOMEWHAT BY SUCH A SIGNIFICANT FEATURE DOWNWIND. OTHERWISE...CLIMATOLOGY WILL PREVAIL. CONDITIONS WILL REMAIN MAINLY ON THE DRY SIDE...BUT THE HUMID AUGUST AIR MASS WILL SUPPORT LOCALLY STRONGER SHOWERS IF THE INVERSION WEAKENS FOR ANY REASON. THE GENERALLY DRY WEATHER...LEEWARD AT LEAST...LIKELY WILL CARRY A KEY INDEX FOR FIRE WEATHER OVER AN IMPORTANT THRESHOLD WITHIN THE NEXT TWO DAYS OR SO. AFTERWARD...UNTIL SIGNIFICANT RAIN FALLS...ANY PERIOD OF MODERATELY STRONG WINDS WITH LOW HUMIDITY COULD POTENTIALLY CREATE THE RISK OF EXTREME FIRE BEHAVIOR...REQUIRING A RED FLAG WARNING. THESE CONDITIONS ARE NEITHER IMMINENT NOR EXPECTED...BUT WILL REQUIRE CONSIDERATION...LIKELY UNTIL THE WINTER RAINY SEASON BEGINS SOMETIME THIS FALL. && .MARINE... NO SIGNIFICANT SWELLS ARE EXPECTED TO REACH THE STATE THROUGH THE FORECAST PERIOD. WINDS SHOULD REMAIN JUST BELOW THE THRESHOLD FOR A SMALL CRAFT ADVISORY IN THE WINDIER MARINE ZONES THROUGH AT LEAST EARLY NEXT WEEK. && .HFO WATCHES/WARNINGS/ADVISORIES... NONE. && $$ |
| #531404 (Received by flhurricane at: 2:05 AM 03.Aug.2012) AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 159 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE WILL BECOME CENTERED OFF THE SOUTHEAST COAST FRIDAY INTO THE WEEKEND...ALLOWING FOR WARM AND HUMID CONDITIONS ACROSS THE LOCAL AREA. ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE POSSIBLE INTO NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... SKIES BECOMING MOSTLY CLEAR ACRS THE AREA NOW...WITH A FEW SITES OVER INTERIOR SOUTHERN VA DEVELOPING VSBYS 1-3 SM. REMOVED PRECIP FOR THE OVERNIGHT PERIOD W/ THINKING THAT ANY CONVECTION WILL STAY OFF TO THE SOUTH. GRIDDED FCST WILL CARRY PATCHY FOG OVERNIGHT FOR INTERIOR VA ZONES ALONG AND SOUTH OF I-64 WHERE RAIN WAS FAIRLY WIDESPREAD. LOWS GENLY IN THE UPR 60S TO LWR 70S. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... STUBBORN SHORT WAVE TROUGH WILL CONTINUE THROUGH SATURDAY NIGHT/SUNDAY MORNING BEFORE FINALLY BREAKING DOWN AND LIFTING NORTHEAST. MODELS SUGGEST UPPER LEVEL LOW WILL PARK OVER EASTERN NC THROUGH TOMORROW AFTERNOON BEFORE PHASING WITH UPPER LEVEL SHORT WAVE. VORT MAX WILL TRACK THROUGH WV FRIDAY BEFORE LIFTING INTO MD/SOUTHERN PA FRIDAY EVENING PLACING BEST CHANCE POPS ACROSS NORTHERN ZONES. HIGH PRESSURE WILL THEN BUILD INTO THE REGION THROUGH SUNDAY ALLOWING FOR CONTINUED ABOVE NORMAL DAYTIME TEMPERATURES. WEAK SYNOPTIC FLOW WILL ALLOW FOR SEA BREEZE INFLUENCES AND ISOLATED TO SCATTERED AFTERNOON/EARLY EVENING SHOWERS. THERE ALSO EXIST SPATIAL AND TIMING DIFFERENCES IN MID LEVEL DISTURBANCES THAT COULD ALSO HELP ENHANCE CHANCES FOR AFTERNOON/EVENING THUNDERSTORMS. A COLD FRONT WILL LOCATE FROM THE MIDWEST INTO THE GREAT LAKES REGION AS AN UPPER LEVEL STORM SYSTEM TRACKS THROUGH SOUTHERN CANADA AND INTO THE GREAT LAKES REGION BY THE END OF THE WEEKEND. SKIES WILL BE MOSTLY SUNNY TO PARTLY CLOUDY WITH SOUTHERLY FLOW PREVAILING. TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL WITH DAYTIME TEMPERATURES UPPER 80S TO LOW/MID 90S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FRNTL BNDRY PROGGED TO STALL NORTH OF FA EARLY NEXT WEEK. MODELS CONT TO SHOW LEE TROF AND ENUF MOISTURE ARND REGION TO KEEP CHC POPS MON/TUE. MOISTURE SHIFTS A BIT FURTHER SOUTH WED SO BEST CHC POPS WILL SHIFT ACROSS SRN HALF OF FA. CHC POPS THU AS COLD FRONT MOVES ACROSS REGION. TEMPS NEAR NORMAL THRU THE PERIOD. HIGHS U80S-L90S. LOWS IN THE U60S-M70S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... THE SURFACE PRESSURE GRADIENT REMAINS RATHER NEBULOUS ACROSS THE MID ATLANTIC...BUT THE CHARACTER OF THE OVERALL PATTERN IS LOWER PRESSURE WEST OF THE APPALACHIANS...WITH HIGH PRESSURE OVER THE WESTERN ATLANTIC. THIS WILL MAINTAIN A LIGHT SOUTHERLY WIND AROUND 3-5KT OVERNIGHT. ADDITIONALLY...CURRENT DEWPOINT DEPRESSIONS ARE AROUND 5-8F AT THE TAF SITES. HENCE IFR CONDITIONS ARE NOT EXPECTED GIVEN THE COMBINATION OF A LIGHT WIND AND THE LATEST DEWPOINT DEPRESSIONS. THERE STILL COULD BE A PERIOD OF MVFR CONDITIONS AROUND SUNRISE MOST LIKELY OCCURRING AT RIC/SBY/ECG. OTHERWISE...THE SKY SHOULD BE MOSTLY CLEAR/MOSTLY SUNNY FOR THE REMAINDER OF TONIGHT INTO FRIDAY MORNING. AN INCREASE IN CUMULIFORM CLOUDS ARE EXPECTED BY AFTERNOON WITH ISOLATED TO SCATTERED THUNDERSTORMS DURING THE AFTERNOON/EARLY EVENING. THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON/EVENING OVER THE WEEKEND...WITH AN INCREASED CHANCE OF THUNDERSTORMS EARLY NEXT WEEK AS A COLD FRONT APPROACHES FROM THE NORTHWEST. && .MARINE... NO FLAGS AS S-SW WND FLOW ARND OFFSHORE RIDGE DOMINATES THRU THE WEEKEND. ONLY THREAT FOR STRONGER WINDS WILL BE IN SCT CONVECTION WHICH IS HANDLED THROUGH STATEMENTS OR WARNINGS. SOME INCREASE IN P-GRDNT LATE SUNDAY AHEAD OF APPRCHG TROF. MARGINAL SCA CONDITIONS POSSIBLE...ESPECIALLY ACROSS NRN COASTAL WATERS WHERE SEAS OUT NR 20 NM MAY REACH 5 FT. OTW...WINDS WINDS BELOW 20 KTS WITH 2-3 FT SEAS EXPECTED. && .EQUIPMENT... KDOX RADAR IS DOWN DUE TO A FAILED AZIMUTH MOTOR. PARTS HAVE BEEN ORDERED. HOWEVER, REPAIRS MAY TAKE SEVERAL DAYS TO COMPLETE. RETURN TO SERVICE IS NOT KNOWN AT THIS TIME. FURTHER DETAILS WILL BE PASSED ALONG AS THEY BECOME AVAILABLE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...LKB |
| #531403 (Received by flhurricane at: 1:57 AM 03.Aug.2012) AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 135 AM EDT FRI AUG 3 2012 .SYNOPSIS... BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE NORMAL DAYTIME TEMPERATURES THROUGH THE WEEKEND ACCOMPANIED BY ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENINGS. A WEAK COLD FRONT WILL APPROACH THE AREA MONDAY...BUT COULD LINGER AS IT WEAKENS SLOWLY THROUGH MID-WEEK...BRINGING INCREASING THUNDERSTORM CHANCES TO THE AREA. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 10:30 PM THURSDAY...LATEST RADAR LOOPS SHOW THREAT OF STRONG TO SEVERE CONVECTION HAS FINALLY ENDED FOR THE NIGHT. WITH CONTINUED COOL AIR ALOFT AND RESIDUAL BOUNDARIES CANNOT RULE OUT THE SPOT SHOWER HOWEVER. EXPECT OVERNIGHT TEMPERATURES NOT MUCH DIFFERENT FROM PRESENT READINGS...MID 70S MOST LOCATIONS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...PRETTY TYPICAL EARLY AUGUST WEATHER EXPECTED ACROSS THE EASTERN CAROLINAS FOR THE SHORT TERM. RESIDUAL TROUGH AT 500MB WILL BE SQUEEZED OUT BY MID LEVEL RIDGES ADVANCING BOTH FROM THE WEST AND THE EAST. GUIDANCE INDICATES THAT SOME PORTION OF THIS TROUGH WILL LAST WELL INTO FRIDAY WITH SLIGHTLY LOWER 1000-500MB THICKNESSES AND COOLER 500MB TEMPS...EVEN AS THE VORT ITSELF WEAKENS SIGNIFICANTLY. WITH PWATS AROUND 1.75 INCHES...SOMEWHAT ENHANCED ML LAPSE RATES...AND SURFACE TEMPS RISING INTO THE LOW 90S...BELIEVE THERE WILL BE AT LEAST ISOLATED CONVECTION FOCUSED PRIMARILY ON THE SEA BREEZE FRIDAY. LIKE THE INHERITED SCHC POP FRIDAY AND WILL MAKE ONLY MINIMAL UPDATES TO THAT. AS RIDGE ELONGATES AND BUILDS OVERHEAD SATURDAY...OVERALL CONVECTIVE COVERAGE WILL BE LESS. IT IS INTERESTING TO NOTE THAT EVEN AS 500MB TEMPS RISE...850MB TEMPS FALL SLIGHTLY SO SURFACE TEMPS WILL BE A LITTLE COOLER SATURDAY...RIGHT AROUND 90. SOME DRIER MID LEVEL AIR AND MUCH WEAKER ML LAPSE RATES SUGGESTS CONVECTION WILL BE HARD TO COME BY SATURDAY...BUT WILL CONTINUE SCHC POP ALONG THE SEA BREEZE DURING THE AFTN. MINS EACH NIGHT WILL BE RIGHT AROUND CLIMO...71-74 MOST PLACES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 300 PM THURSDAY...MAIN FEATURES AT THE MID LEVELS WILL BE A SIGNIFICANT SHORTWAVE MOVING ACROSS THE GREAT LAKES EARLY WITH MID LEVEL RIDGING TAKING PRECEDENCE LATER IN THE PERIOD. AT THE SURFACE...THE AFOREMENTIONED SHORTWAVE WILL PUSH A FRONT DOWN NORTH OF THE AREA EARLY NEXT WEEK MAKING ITS CLOSEST APPROACH LATE TUESDAY INTO WEDNESDAY. AFTER A BRIEF LULL OR STALL...A SECONDARY FRONT BUOYED BY HEIGHT FALLS ACROSS THE EASTERN U.S. THURSDAY WILL MOVE THE BOUNDARIES CLOSER. POPS INCREASE FROM SUNDAYS MINIMAL CHANCE VALUES TO LOW CHANCE MONDAY AND TUESDAY. WEDNESDAYS FORECAST REPRESENTS A SLIGHT DECREASE IN VALUES FOLLOWED THURSDAY BY AN INCREASE. NO SIGNIFICANT CHANGES TO TEMPERATURE FORECAST. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...LOW PROBABILITIES OF SHRA/TSRA OVERNIGHT. VFR CONDITIONS ARE LIKELY TO GIVE WAY TO MVFR VSBYS BY 08Z AS SKIES CLEAR. CONFIDENCE OF THE TIMING AND DURATION OF IFR LOW BUT GENERALLY FROM 09-11Z. VFR EXPECTED 1-2 HRS AFTER SUNRISE. CONVECTION SHOULD DEVELOP AFT 16Z BUT NO ORGANIZED CONVECTION EXPECTED DUE TO NUMEROUS OUTFLOW BOUNDARY INTERACTIONS. WILL LEAVE MENTION OF CONVECTION FOR LATER TAFS. SE-S WINDS EXPECTED. EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR...FOLLOWED BY CHANCE FOR SHOWERS AND THUNDERSTORMS EACH AFTERNOON AND EVENING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 10:30 PM THURSDAY...FOR THE OVERNIGHT PERIOD EXPECT SW WINDS OF 10 TO 15 KT AND SEAS OF 2-4 FEET...HIGHEST OUTER PORTION. LATEST RADAR LOOPS SHOW NO THREAT OF STRONG CONVECTION THROUGH DAYBREAK FRIDAY. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...PRETTY UNIFORM CONDITIONS ACROSS THE WATERS THROUGH THE SHORT TERM AS BERMUDA RIDGE BEGINS TO RIDGE BACK TO THE WEST FROM THE ATLANTIC OCEAN. S/SW WINDS OF AROUND 10 KTS WILL PERSIST FRIDAY AND SATURDAY...WITH MINOR FLUCTUATIONS UP TO 15 KTS POSSIBLE AT TIMES. THESE WINDS WILL PRODUCE A 2-3FT/5SEC SW WIND WAVE...WHICH WILL COMBINE WITH A 2FT/8SEC SE SWELL TO CREATE 2-3 FT SEAS ACROSS ALL COASTAL ZONES. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 PM THURSDAY...ROUTINE SUMMERTIME CONDITIONS EXPECTED FOR THE COASTAL WATERS THROUGH THE PERIOD. WIND SPEEDS DO INCREMENTALLY INCREASE THROUGH THE PERIOD AS A FRONT EDGES EVER SO CLOSER FROM THE NORTH. EXPECT 10-15 KNOTS THROUGHOUT THE PERIOD WITH ACTUAL WINDS CLOSER TO THE LOWER END OF THE RANGE EARLY AND HIGHER LATE. THE LATEST WAVEWATCH IS ADVERTISING SEAS IN A NARROW RANGE OF 2-3 FEET WHICH SEEMS REASONABLE CONSIDERING THE SYNOPTIC PATTERN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ |
| #531401 (Received by flhurricane at: 1:48 AM 03.Aug.2012) AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 141 AM EDT FRI AUG 3 2012 .SYNOPSIS... HIGH PRESSURE REMAINS OVER THE ATLANTIC THROUGH SATURDAY. A COLD FRONT WILL SLOWLY WORK ITS WAY ACROSS THE REGION SUNDAY THROUGH MONDAY. HIGH PRESSURE RETURNS ON TUESDAY...THEN A SERIES OF FRONTAL BOUNDARIES WILL IMPACT THE AREA FOR THE MIDDLE OF THE NEW WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... MOSTLY CLEAR SKIES CONTINUE TONIGHT AS HIGH PRESSURE BUILDS OVER THE AREA. CURRENT FORECAST ON TRACK WITH ONLY MINOR UPDATES TO TEMP/DP TO REFLECT CURRENT TRENDS. OTHERWISE...WITH THE EASTWARD MOVEMENT OF THE TROUGH...FLOW FLATTENS ALOFT TONIGHT AS HEIGHTS SLOWLY RISE. ANOTHER VERY WARM AND MUGGY NIGHT IS IN STORE FOR THE AREA. FOLLOWED A MOS BLEND FOR OVERNIGHT MINS. PATCHY FOG IS ALSO FORECAST ACROSS PARTS OF THE AREA. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... HEIGHTS CONTINUE TO RISE IN THE WAKE OF THE DEPARTING UPPER TROUGH OFF THE EAST COAST AND ANOTHER ONE AMPLIFYING ACROSS THE NORTHERN PLAINS. AS SUCH...WARM TO HOT WEATHER CONTINUES IN THIS TIME FRAME. WILL FOLLOW A MOS BLEND BOTH DAYS...AS FRIDAY APPEARS TO BE THE HOTTER OF THE TWO DAYS. BOTH NAM AND GFS SHOW WARMER LOW LEVEL THICKNESS VALUES FOR FRIDAY...LIKELY DUE TO MORE MARINE FLOW SATURDAY. MOS HAS BEEN CONSISTENT IN FORECASTING LOWER TEMPS SATURDAY. FOR THIS REASON...WILL NOT ISSUE HEAT ADVISORY FOR NYC FOR TWO CONSECUTIVE DAYS OF 95 OR BETTER. I DO BELIEVE HEAT INDICES WILL REACH 95 ACROSS MUCH OF THE METRO AREA FRIDAY...BUT SHOULD FALL JUST SHORT SATURDAY. THIS WILL NEED TO BE MONITORED AS A SLIGHT CHANGE IN TEMPS OR DPS WILL HAVE A MAJOR AFFECT IN HEAT INDICES. THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN FACING BEACHES ON FRIDAY. FRIDAY NIGHT WILL BE QUITE WARM AND MUGGY ONCE AGAIN. FOG LIKELY AS INDICATED BY MODEL TIME HEIGHT CROSS SECTIONS AND MOS. AS FOR SENSIBLE WEATHER...A COLD FRONT DROPS SOUTH ACROSS NORTHERN NY STATE AND NEW ENGLAND...AND WILL BE PRECEDED BY A PRE-FRONTAL TROF FRIDAY AFTERNOON AND EVENING. THERE IS INCREASED SURFACE BASED INSTABILITY DUE TO HIGHER TEMPS AND DEW POINTS....AND MID LEVEL LAPSE RATES THIS TIME AROUND WILL APPROACH 7C LATE IN THE DAY. SCATTERED STRONG CONVECTION REMAINS POSSIBLE IN THE AFTERNOON...PRIMARILY NORTH AND WEST OF NYC. SHEAR REMAINS WEAK. AS SUCH...SLOW MOVING PULSE STORMS ARE THE MAIN THREAT. DIURNAL CONVECTION LIKELY ONCE AGAIN SATURDAY. WILL CONTINUE WITH CHANCE POPS NW...LOWER TO THE SE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... ANY SHOWERS/THUNDERSTORMS THAT DEVELOP SATURDAY AFTERNOON WILL GRADUALLY TAPER OFF SATURDAY NIGHT AS THERMAL TROUGH DISSIPATES WITH LOSS OF DIURNAL HEATING. SEVERAL WEAK SHORTWAVES WILL MOVE THROUGH THE REGION SUNDAY MORNING...SO WILL CARRY CHANCE POPS IN THE FORECAST...BUT THE BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL HOLD OFF UNTIL LATER IN THE DAY AS A STRONG COLD FRONT MOVES THROUGH THE OHIO VALLEY AND A PRE-FRONTAL TROUGH AHEAD OF THAT FRONT MOVES INTO THE REGION. STRONG SOUTHERLY WINDS WILL DEVELOP SUNDAY AFTERNOON AS THE PRESSURE GRADIENT TIGHTENS BETWEEN HIGH PRESSURE ANCHORED OFFSHORE AND THE APPROACHING COLD FRONT. SFC DEW POINTS WILL PUSH WELL INTO THE 70S...AND WITH MAX TEMPS IN THE MID TO UPPER 80S...AROUND 90 IN/AROUND NYC...INSTABILITY LEVELS WILL BE QUITE HIGH WITH CAPE VALUES BETWEEN 1500-2000 J/KG. IN ADDITION...PWATS WILL INCREASE TO 2-2.5 INCHES. ALTHOUGH SFC TEMPS WILL NOT BE EXCEPTIONALLY HIGH... THE COMBINATION OF TEMPS NEAR 90 WITH WITH SFC DEW POINTS IN THE MID AND UPPER 70S WILL RESULT IN DANGEROUS HEAT INDICES...TOPPING OFF IN THE MID TO UPPER 90S...POSSIBLY APPROACHING 100 IN/AROUND NYC. COLD FRONT MOVES INTO THE REGION SUNDAY EVENING...AND HIGHEST POPS WILL OCCUR DURING THE OVERNIGHT HOURS SUNDAY NIGHT INTO MONDAY MORNING. WITH LOSS OF DIURNAL HEATING...SEVERE THREAT WILL BE DIMINISHED. MID-LEVEL WINDS SHOULD ALLOW THE STORMS TO MOVE THROUGH THE REGION FAIRLY QUICKLY...BUT WITH PWATS REMAINING SO HIGH... URBAN/SMALL STREAM FLOODING...AND EVEN FLASH FLOODING...IS STILL POSSIBLE. COLD FRONT PUSHES THROUGH THE REGION MONDAY AFTERNOON...AND BECOMES NEARLY STATIONARY SOUTH OF LONG ISLAND. POPS TAPER OFF FROM WEST TO EAST...AND DEW POINTS FALL INTO THE 60S THROUGHOUT THE DAY AS HIGH PRES OVER THE MIDWEST NOSES ITS WAY EAST. HIGH PRES OVER THE AREA WILL RESULT IN A PLEASANT DAY ON TUESDAY... PROBABLY THE BEST DAY OF THE LONG TERM PERIOD...WITH PARTLY CLOUDY SKIES...LIGHT NORTH WINDS TURNING SOUTH WITH AFTERNOON SEA BREEZES...AND TEMPS TOPPING OFF IN THE MID 80S. UNSETTLED WEATHER RETURNS ON WEDNESDAY AS STATIONARY FRONT SOUTH OF THE REGION LIFTS BACK NORTH AS A WARM FRONT...THEN A COLD FRONT SWINGS THROUGH ON THURSDAY. TEMPS WILL BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THE PERIOD. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... A WEAK PRESSURE PATTERN WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. VFR CONDITIONS ARE EXPECTED IN MOST SPOTS OVERNIGHT HOWEVER...REDUCED VISIBILITIES IN BR EXPECTED FOR SOME TERMINALS AFTER MAINLY 07Z. LOW CONFIDENCE REGARDING HOW LOW THEY GET REDUCED PARTICULARLY AT KHPN AND KGON. WINDS GENERALLY SW UNDER 10 KT. DURING THE DAY TODAY...SEA BREEZES ARE EXPECTED TO SHIFT WINDS IN THE AFTERNOON. AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE LATE AFTERNOON INTO EARLY EVENING...BUT NOT ENOUGH CONFIDENCE TO EVEN INCLUDE IN A PROB30 GROUP AT THIS TIME. WINDS WILL BECOME LIGHT AND VARIABLE ONCE AGAIN TONIGHT. OUTLOOK FOR 06Z SAT THROUGH TUE... .SAT...CHC VSBYS BELOW 6SM IN BR EARLY AM...ESPECIALLY OUTLYING TERMINALS. ISOLD/SCT TSTMS POSSIBLE LATE AFTN/EVE. .SUN...GUSTY S WINDS. TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .MON...TSTMS POSSIBLE WITH AN APPROACHING COLD FRONT. .TUE...VFR. && .MARINE... SOUTHERLY WIND FLOW CONTINUES INTO SATURDAY AS HIGH PRESSURE REMAINS OVER THE ATLANTIC...AND A WEAK FRONT APPROACHES BUT REMAINS TO THE NORTH. SUB SCA CONDITIONS ARE EXPECTED...WITH LOCAL ENHANCEMENT TO WINDS DURING THE AFTERNOON AND EVENING DUE TO SEA BREEZES...DIFFERENTIAL HEATING BETWEEN LAND AND WATER. SUB-SCA CONDS CONTINUE SATURDAY NIGHT INTO SUNDAY MORNING...THEN THE SOUTHERLY PRES GRADIENT INCREASES LATE SUNDAY THROUGH MONDAY MORNING...RESULTING IN 25 KT WIND GUSTS...MAINLY ON THE OCEAN WATERS...AND OCEAN SEAS BUILDING TO 5-7 FT. CONDS SUBSIDE TO SUB-SCA CRITERIA MONDAY EVENING. COLD FRONT MOVES THROUGH THE WATERS SUNDAY NIGHT. THUNDERSTORMS WILL BE CAPABLE OF HEAVY RAIN...RESULTING IN DIMINISHED VSBYS...AND THUNDERSTORM WIND GUSTS EXCEEDING 34 KT. SUB-SCA CONDS THEN EXPECTED MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK. && .HYDROLOGY... SCATTERED TO ISOLATED THUNDERSTORMS DURING THE DAYTIME COULD RESULT IN LOCAL NUISANCE URBAN/POOR DRAINAGE FLOODING FRIDAY AND SATURDAY. A LOW END FLASH FLOOD THREAT CONTINUES. THUNDERSTORMS CAPABLE OF HEAVY RAIN SUNDAY NIGHT INTO MONDAY MORNING WILL RESULT IN URBAN/POOR DRAINAGE/SMALL STREAM FLOODING. THERE IS A LOW END THREAT FOR FLASH FLOODING DURING THIS TIME AS WELL. && .TIDES/COASTAL FLOODING... TIDE LEVELS MAY APPROACH MINOR COASTAL FLOODING VALUES DURING THE HIGH TIDE TONIGHT. NO COASTAL FLOOD STATEMENT WILL BE ISSUED AT THIS TIME. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...MPS/PW |
| #531400 (Received by flhurricane at: 1:38 AM 03.Aug.2012) AFDBRO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 1233 AM CDT FRI AUG 3 2012 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...HIGH PRESSURE AT THE SURFACE AND ALOFT WILL MAINTAIN VFR CONDITIONS THE NEXT 24 HOURS. FEW-SCT CU FIELD IS EXPECTED TO REMAIN ALONG AND EAST OF HIGHWAY 281. SOUTHEAST WINDS TO GUSTS BETWEEN 20 AND 25 KNOTS BETWEEN 17Z-03Z. && .PREV DISCUSSION... /ISSUED 642 PM CDT THU AUG 2 2012/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...VFR CONDITIONS WILL PERSIST FOR THE NEXT 24 HOURS. GUSTY SOUTHEAST WINDS SHOULD BEGIN TO SUBSIDE AFTER SUNSET WITH LIGHT WINDS OVERNIGHT. SOUTH TO SOUTHEAST WINDS INCREASE AROUND MID MORNING ON FRIDAY WITH GUSTS 20 TO 25 KNOTS EXPECTED BY FRIDAY AFTERNOON. PREV DISCUSSION... /ISSUED 146 PM CDT THU AUG 2 2012/ SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...STRONG UPPER RIDGING...CLEARLY EVIDENT ON WATER VAPOR REMAINS CENTERED OVER CENTRAL AND NORTHEAST TEXAS THIS AFTERNOON. THE SUBTROPICAL RIDGE AT THE SURFACE IS CENTERED A FEW HUNDRED MILES SOUTH OF MOBILE ALABAMA. WITH THIS THE WEATHER PATTERN HAS REMAINED VERY CONSISTENT WITH LITTLE LOW LEVEL MOISTURE ABOVE THE SURFACE MOSTLY CLEAR TO COMPLETELY CLEAR SKIES AND HOT TEMPERATURES WITH A STEADY SOUTHEAST WIND. SIGNIFICANT CHANGES ARE NOT EXPECTED FOR FRIDAY. SURFACE AN UPPER RIDGING WILL SLIDE SLIGHTLY EASTWARD...WITH THE UPPER RIDGING WEAKENING A BIT. THIS WILL SHIFT SURFACE FLOW SLIGHTLY MORE EASTERLY AS THE MESOSCALE THERMAL LOW TAKES A LITTLE BIGGER ROLE WITH THE DIMINISHING SYNOPTIC SCALE PRESSURE GRADIENT...THIS WILL SLIGHTLY INCREASE SURFACE AND LOW MOISTURE NEAR THE COAST BUT SHOULD NOT PRODUCE A SIGNIFICANT CHANGE IN OUR WEATHER OVERALL. STILL HOT WITH SOUTH TO SOUTHEAST WINDS BECOMING GUSTY IN THE AFTERNOON. NAM12...AND TO A LESSER EXTENT THE GFS SHOW A WEAK 500MB VORT LOBE PUSHING THROUGH FRIDAY EVENING BUT LITTLE SURFACE REFLECTION EXPECTED. LONG TERM /SATURDAY THROUGH THURSDAY/...NO CHANGES WERE MADE TO THE FORECAST. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL PREVAIL DAILY THROUGH THE PERIOD...AS BROAD MID-LEVEL HIGH PRESSURE GRADUALLY RETROGRADES AND RE-CENTERS ITSELF FROM OKLAHOMA TO THE DESERT SOUTHWEST...PRECIPITABLE WATER VALUES INCREASE TO AROUND 2 INCHES AND PERSIST...AND MID-LEVEL LOW PRESSURE GRADUALLY MOVES WEST ACROSS THE CENTRAL GULF OF MEXICO. TEMPERATURES WILL HOLD AT ABOVE NORMAL LEVELS THROUGH THE PERIOD. MARINE...TONIGHT THROUGH FRIDAY NIGHT...SCEC CONDITIONS EXPECTED THROUGH THIS EVENING ON MOST OF THE LOWER TEXAS COAST...SHIFTING TO THE GULF WATERS THROUGH THE OVERNIGHT PERIOD. OVERALL CONDITIONS EXPECTED TO CHANGE LITTLE THROUGH FRIDAY WITH SLIGHTLY STRONGER WINDS...AND AT LEAST SOME POSSIBILITY OF SMALL CRAFT ADVISORY LEVEL WINDS FRIDAY NIGHT. SEAS SHOULD REMAIN MODERATE OVERALL...PICKING UP IN THE OVERNIGHT HOURS AS WINDS INCREASE. SATURDAY THROUGH THURSDAY...GENERALLY MODERATE WINDS AND SEAS ARE EXPECTED ALONG THE LOWER TEXAS COAST DURING THE WEEKEND AS HIGH PRESSURE OVER THE GULF OF MEXICO INTERACTS WITH THERMAL LOW PRESSURE OVER NORTHERN MEXICO. LIGHTER WINDS AND LOWER SEAS ARE EXPECTED FOR MONDAY THROUGH WEDNESDAY AS HIGH PRESSURE BECOMES MORE OF AN INFLUENCE OVER THE WESTERN GULF OF MEXICO. WINDS AND SEAS MAY BEGIN TO INCREASE BEGINNING AROUND THURSDAY AS A TROPICAL SYSTEM POSSIBLY MOVES INTO THE CENTRAL GULF OF MEXICO. FIRE WEATHER...ENHANCED FIRE DANGER CONDITIONS WILL BE POSSIBLE MAINLY FROM 281 WESTWARD ON FRIDAY AFTERNOON. 20FT WINDS ARE EXPECTED TO BE BELOW CRITICAL FIRE DANGER LEVELS...BUT MINIMUM RELATIVE HUMIDITY VALUES WILL BE CONTINUE TO BE QUITE LOW. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531399 (Received by flhurricane at: 1:38 AM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 129 AM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THE WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... DEBRIS CLOUDINESS IS QUICKLY DIMINISHING AND SHOULD SEE CLEAR TO MOSTLY CLEAR SKIES PREVAIL. THERE ARE INDICATIONS THAT SOME STRATUS COULD DEVELOP ACROSS THE CSRA AND FAR WESTERN AREAS PRIOR TO SUNRISE. GUIDANCE IS OFFERING MIXED SIGNALS ON HOW WIDESPREAD THE STRATUS WILL BECOME...BUT WILL SHOW SKIES BECOMING PARTLY CLOUDY ACROSS THE FAR WEST TO TREND. PATCHY FOG WILL BE POSSIBLE ESPECIALLY WHERE RAINS FELL EARLIER IN THE DAY. WIDESPREAD DENSE FOG IS NOT EXPECTED AT THIS TIME. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... A TYPICAL SUMMERTIME PATTERN WILL PRESENT ITSELF THIS WEEKEND AS ATLANTIC HIGH PRESSURE EXPANDS OVER THE SOUTHEAST WHILE MID LVL RIDGING MAINTAINS A STRONG HOLD OVER THE CENTRAL UNITED STATES. WITH THESE SYNOPTIC FEATURES IN PLACE...LIGHT ONSHORE FLOW WILL PERSIST THIS WEEKEND AND RESULT IN FAVORABLE CONDITIONS FOR AN INLAND MOVING SEABREEZE EACH AFTERNOON ALONG WITH PULSE TYPE SHOWERS/THUNDERSTORMS THROUGH EACH EVENING. ACTIVITY WILL LIKELY DIMINISH QUICKLY WITH SUNSET EACH EVENING GIVEN WEAK MID/UPPER LVL SUPPORT. ALTHOUGH AN ISOLATED STRONG STORM IS POSSIBLE WITH THIS PULSE TYPE CONVECTION AND BOUNDARY INTERACTIONS...THE OVERALL SEVERE WEATHER THREAT WILL REMAIN LOW OVER THE PERIOD. IN GENERAL...HAVE MAINTAINED A 20 POP FORECAST FOR FRIDAY...WITH AN INCREASING TREND TO 20-30 POPS ON SATURDAY AND SUNDAY AS PWATS APPROACH 2 INCHES OVER THE REGION. HIGHEST CHANCES OF PRECIP SHOULD OCCUR OVER INLAND AREAS ALONG AND AHEAD OF THE AFTERNOON SEABREEZE. ACTIVITY WILL REMAIN DIURNAL IN NATURE GIVEN WEAK MID/UPPER LVL SUPPORT. THE OVERALL SEVERE WEATHER THREAT WILL ALSO REMAIN LOWER THAN PREVIOUS DAYS. OVERALL TEMPS WILL REMAIN A DEGREE OR TWO ABOVE CLIMATOLOGY...WITH 1000-850 THICKNESS VALUES SUPPORTING HIGHS IN THE LOW 90S. OVERNIGHT LOWS WILL BE IN THE LOW/MID 70S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... MODELS SHOW SUBTLE HIGH FALLS AT THE BEGINNING OF THE PERIOD AS A LOW PRESSURE SYSTEM MOVES EASTWARD ACROSS THE NEW ENGLAND AREA. ITS ASSOCIATED COLD FRONT WILL LIKELY STALL OUT WELL NORTH OF THE AREA SOMETIME AROUND MID WEEK. MEANWHILE...THE UPPER RIDGE ACROSS CENTRAL UNITED STATES WILL CONTINUE TO STRENGTHEN THROUGH THE PERIOD. AT THE SURFACE...THE FORECAST AREA WILL REMAIN SANDWICHED BETWEEN THE SURFACE HIGH PRESSURE OVER THE MIDDLE OF THE UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. THIS PATTERN COULD ALLOW FOR AN INCREASE IN CONVECTION...ESPECIALLY AS CONVECTION DEVELOPS ALONG THE STALLED FRONT AND INTERACTS WITH OTHER BOUNDARIES...LIKE THE SEA BREEZE. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS WITH LOW TO MID 90S EXPECTED DURING THE AFTERNOON AND DIPPING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... MAINLY VFR. INTRODUCED PREVAILING MVFR VSBYS AT KSAV WHERE LIGHT WINDS...MAINLY CLEAR SKIES AND WET GROUNDS FROM EARLIER TSTMS COULD PROMOTE SOME GROUND FOG DEVELOPMENT. SCATTERED TSTMS ARE EXPECTED THIS AFTERNOON...MAINLY WEST OF THE TERMINALS SO WILL LEAVE ANY MENTION OUT OF THE 03/06Z TAFS. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER THAN 30 PERCENT CONFIDENCE LEVEL AT THIS TIME. && .MARINE... THE PRESSURE PATTERN REMAINED WEAK OVER COASTAL WATERS DUE TO EARLIER THUNDERSTORMS...SUPPORTING LIGHT/VARIABLE WINDS. 00Z NAM GUIDANCE SUGGESTS THAT THE S/SW GRADIENT SHOULD REDEVELOP OVERNIGHT...ACCOMPANIED BY SOME INCREASE IN WIND SPEEDS. HOWEVER... WINDS SHOULD GENERALLY REMAIN 15 KT OR LESS. ATLANTIC HIGH PRESSURE WILL EXPAND OVER THE WATERS THIS WEEKEND... LEADING TO CONDITIONS WELL BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO EARLY NEXT WEEK. IN GENERAL...SOUTH WINDS BETWEEN 10-15 KT WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE WITH HIGHEST WINDS EXPECTED NEAR INLAND MOVING SEABREEZE CIRCULATIONS AND EARLY NIGHT SURGES. WINDS MAY BRIEFLY BECOME SOUTHEAST EACH AFTERNOON/EVENING AS THE SEABREEZE MAKES WAY INLAND. SEAS WILL REMAIN BETWEEN 1-3 FEET...WITH SWELLS FROM THE SOUTH/SOUTHEAST. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531398 (Received by flhurricane at: 1:35 AM 03.Aug.2012) AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 125 AM EDT FRI AUG 3 2012 .AVIATION...FEW SHOWERS DIMINISHING NEAR KPBI. OTHERWISE, VFR WILL PREVAIL UNTIL SCATTERED TSRA DEVELOPS THIS AFTERNOON. SO HAVE VCTS ALL SITES. MORNING SHOWERS COULD BEGIN DEVELOPING AS EARLY AS 15Z...SO LEFT THIS IN FROM INHERITED FCST. MVFR OR IFR IS POSSIBLE WITH THE AFTERNOON TSRA, BUT THOSE CONDITIONS WOULD BE BRIEF. /GREGORIA && .PREV DISCUSSION... /ISSUED 1019 PM EDT THU AUG 2 2012/ UPDATE...CONVECTION FINALLY ENDING ACROSS THE REGION, ALTHOUGH A FEW SHOWERS AND STORMS CANNOT BE RULED OUT THROUGH MIDNIGHT. OTHERWISE, TRANQUIL AND WARM CONDITIONS EXPECTED LATE TONIGHT. A FEW SHOWERS AND STORMS MAY FORM THROUGH THE NIGHT OVER THE ATLANTIC AND GULF WATERS, WITH THE BULK OF THAT ACTIVITY REMAINING OFFSHORE. PREV DISCUSSION... /ISSUED 741 PM EDT THU AUG 2 2012/ AVIATION... SIMILAR CONDITIONS AS THE PREVIOUS FEW EVENINGS WITH DECAYING CONVECTION ACROSS INTERIOR AREAS. CONVECTION IS SLOWLY MOVING NORTHEAST BUT IS NOT EXPECTED TO REACH THE EAST COAST TAF SITES BEFORE THEY DISSIPATE. OTHERWISE LIGHT SOUTHEASTERLY WINDS WILL PREVAIL OVERNIGHT. BELIEVE SHRA/TSRA ACTIVITY MAY INITIATE A BIT SOONER TOMORROW WITH THE CLOSER PROXIMITY OF A TROPICAL WAVE. PREV DISCUSSION... /ISSUED 450 PM EDT THU AUG 2 2012/ UPDATE...POPS WERE ADJUSTED AND LARGELY INCREASED ACROSS A LARGE PORTION OF THE REGION. CONVECTION CONTINUES TO DEVELOP ALONG SEA BREEZE AND OUTFLOW BOUNDARIES, AND WILL BE SLOW TO DIMINISH, WITH NO SIGNIFICANT DECREASE IN ACTIVITY EXPECTED UNTIL AFTER 00Z. PREV DISCUSSION... /ISSUED 232 PM EDT THU AUG 2 2012/ SHORT TERM...TONIGHT THROUGH SUNDAY...LATEST 850MB STREAMLINE ANALYSIS SHOWS A TROPICAL WAVE/TROUGH EXTENDING FROM THE NORTHERN BAHAMAS SOUTH ACROSS CENTRAL CUBA AND INTO THE WESTERN CARIB. LATEST WATER VAPOR IMAGES SHOW A LARGE AREA OF MOISTURE MAINLY TO THE EAST OF THE TROUGH AXIS. MDLS MOVE THIS SYSTEM WESTWARD THROUGH THIS PERIOD WITH MOST OF THE MOISTURE SPREADING ACROSS SOUTH FLORIDA FROM FRI EVENING TO SUNDAY AFTERNOON. GFS ALSO SHOWS AN UPPER LOW MOVING WEST AHEAD OF THE WAVE AND POSITIONS IT WEST OF THE PENINSULA BY SATURDAY AFTERNOON. THE COMBINATION OF THIS TWO SYSTEMS WILL NOT ONLY RESULT IN INCREASED LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT, BUT ALSO INCREASED UPPER LVL DIVERGENCE RESULTING IN INCREASING CHANCES FOR RAIN THROUGH THIS PERIOD. LONG TERM...MONDAY THROUGH THURSDAY...TROPICAL WAVE AND UPPER LOW MENTIONED ABOVE SHOULD MOVE WEST OF THE LOCAL AREA BY MONDAY AND BE REPLACED BY AN ATLANTIC HIGH PRESSURE RIDGE BUILDING WESTWARD. THIS WILL RESULT IN A MODERATE EAST FLOW BEING ESTABLISHED ACROSS THE REGION. THIS WILL TEND FOCUS AFTERNOON CONVECTIVE ACTIVITY MOSTLY OVER INTERIOR/WESTERN AREAS, WHILE NIGHTTIME/EARLY MORNING SHWRS/TSTMS COULD BE EXPERIENCED OVER ERN AREAS. TD#5 JUST EAST OF THE WINDWARD ISLANDS EARLIER THIS AFTERNOON IS EXPECTED TO CONTINUE TO MOVE RATHER FAST WESTWARD NEXT FEW DAYS AND SHOULD BE NEAR THE ISLANDS BY FRIDAY. THE FUTURE TRACK OF THIS SYSTEM WILL GREATER DEPEND ON ITS ORGANIZATION AND INTENSITY AS WELL AS ON THE STRENGTH OF THE HIGH PRESSURE RIDGE CURRENTLY OVER THE WESTERN ATLANTIC NORTH OF THE ISLANDS. THE CURRENT FORECAST THINKING FROM THE NATIONAL HURRICANE CENTER IS THAT THE EASTERLY STEERING CURRENT AROUND THE BASE OF THE RIDGE SHOULD KEEP THE DEPRESSION ON A MAINLY WESTWARD TRACK THROUGH THE CARIBBEAN SEA THROUGH NEXT WEEK. AT THIS TIME, IT IS UNCERTAIN WHETHER MOISTURE ASSOCIATED WITH THIS SYSTEM COULD HAVE ANY EFFECT OVER THE LOCAL AREA. HOWEVER, IF THE LONG RANGE GFS VERIFIES, THERE COULD BE BREEZY CONDITIONS ACROSS THE AREA DUE TO A TIGHTENING PRESSURE GRADIENT BETWEEN THIS SYSTEM AND THE ATLANTIC RIDGE. MARINE...PLEASANT BOATING CONDITIONS SHOULD CONTINUE AT LEAST THROUGH THE PERIOD. HOWEVER...WINDS AND SEAS COULD BE HIGHER NEAR SHOWERS AND STORMS SATURDAY AND SUNDAY AS THE TROPICAL WAVE MOVES ACROSS THE AREA. FIRE WEATHER...NO CONCERNS AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 78 89 75 90 / 30 50 30 40 FORT LAUDERDALE 77 89 77 90 / 30 50 30 40 MIAMI 77 90 77 91 / 30 40 30 40 NAPLES 77 90 76 92 / 20 30 30 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ |
| #531397 (Received by flhurricane at: 1:33 AM 03.Aug.2012) AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 129 AM EDT FRI AUG 3 2012 .SYNOPSIS... WARM AND VERY HUMID WEATHER WILL PERSIST FOR THE NEXT SEVERAL DAYS. A COUPLE OF WEAK FRONTS MAY BRING SCATTERED AFTERNOON AND EVENING SHOWERS OR THUNDERSTORMS FRIDAY. A STRONGER COLD FRONT WILL MOVE THROUGH THE REGION MONDAY AND WILL BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS BOTH SUNDAY AND MONDAY. THE FRONT WILL THEN STALL SOUTH OF NEW ENGLAND...BUT ALLOW FOR SLIGHTLY LESS HUMID AIR TO MOVE INTO THE REGION AFTER MONDAY. ANOTHER COLD FRONT WILL APPROACH FROM THE WEST BY THURSDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 130 AM UPDATE... LOW CLOUD BANK ON CAPE COD AND ISLANDS PERSISTED AS WE THOUGHT EARLIER... BUT SOME HOLES HAVE APPEARED AROUND HYANNIS AND NANTUCKET. EXPECT THESE TO FILL BACK IN FOR REST OF NIGHT WITH SW FLOW AND HIGH DEWPOINTS /70F/. CLOUD BANK SHOULD NOT MAKE MUCH MORE PROGRESS INLAND BASED UPON SATELLITE TRENDS...PROBABLY ONTO S COASTAL MA BUT NOT MUCH FARTHER THAN THAT. SHOULD ALSO SEE PATCHY LOW CLOUDS ACROSS INTERIOR SE MA WHERE FOG FORMS. OTHERWISE MOSTLY CLEAR SKIES EXPECTED OVERNIGHT. FORECAST LOWS IN 60S AND LOWER 70S ON TRACK. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... FRIDAY...ANOTHER WEAK FRONT APPROACHES THE AREA. THERE ARE SOME DISCREPANCIES AMONGST THE MODELS AS TO HOW FAR SOUTH THE FRONT GOES BEFORE IT WASHES OUT. EXPECT ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT. PRECIPITABLE WATER VALUES REMAIN BETWEEN 1.5 AND 1.75 INCHES...SO LOCALLY HEAVY DOWNPOURS ARE POSSIBLE. THESE STORMS WILL BE MUCH LIKE TODAY/S BUT WITH THE POTENTIAL TO DEVELOP FURTHER WEST ACROSS THE INTERIOR ZONES. 850MB TEMPERATURES WARM TO 17-18C...SO TEMPERATURES AT THE SURFACE SHOULD BE WARMER WITH HIGHS IN THE UPPER 80S TO LOW 90S. DEWPOINTS WILL BE HIGH ENOUGH THAT TEMPERATURES PARTICULARLY ACROSS THE EASTERN ZONES WILL FEEL LIKE THEY ARE IN THE UPPER 90S. NOT WARM ENOUGH FOR A HEAT ADVISORY BUT IT CERTAINLY WILL BE HOT AND HUMID. FRIDAY NIGHT...SHOWERS AND THUNDERSTORMS MAY LINGER A BIT LATER INTO THE EVENING THAN TONIGHT THANKS TO SOME LINGERING INSTABILITY...BUT SHOULD WEAKEN SUBSTANTIALLY AFTER SUNSET. ANOTHER NIGHT OF LOW CLOUDS AND FOG EXPECTED WITH PLENTY OF LOW LEVEL MOISTURE IN THE REGION. LOW TEMPERATURES ONCE AGAIN IN THE MID 60S TO LOW 70S. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... BIG PICTURE... MODEL FORECASTS OF 500 MB FLOW ARE SIMILAR THROUGH TUESDAY. ATLANTIC UPPER RIDGE BRINGS RISING HEIGHTS INTO NEW ENGLAND THROUGH SUNDAY...THEN SUPPRESSES SOUTH AND EAST. SHORTWAVE THAT INITIALIZES OVER THE PACIFIC NORTHWEST WILL CROSS THE COUNTRY THIS WEEKEND AND CROSS NEW ENGLAND SUNDAY NIGHT AND MONDAY. THIS SHORTWAVE WILL DRIVE A COLD FRONT THROUGH NEW ENGLAND DURING THIS TIME. A SECOND SHORTWAVE DIVES SOUTHEAST FROM NORTHERN ONTARIO TO MAINTAIN CYCLONIC FLOW OVER THE NORTHEAST USA THROUGH THURSDAY. THE MODELS HANDLE THIS SECOND SHORTWAVE DIFFERENTLY...WITH THE 12Z ECMWF SHARPER AND CONTAINING A CLOSED LOW. SATURDAY... A BUILDING UPPER RIDGE WOULD SUGGEST QUIET WEATHER OVER THE WEEKEND. HOWEVER THE NAM-GFS-ECMWF SHOW A STALLED FRONT EITHER OVER THE MASS-NH BORDER OR JUST NORTH OF OUR AREA WITH A VERY HUMID AIRMASS IN PLACE. SB CAPES 1500-2000 J/KG AND TOTALS AROUND 50...NAM HINTS AT A THETA-E RIDGE OVER NORTHWEST MASS. NEGATIVES INCLUDE NO STRONG JETS ALOFT TO PRODUCE DYNAMIC FORCING AND DRYING ALOFT AS SHOWN BY MODEL SOUNDINGS. LOCAL FORCING SUCH AS COLLIDING BOUNDARIES COULD FORCE A FEW STORMS. THE BEST CHANCE WOULD BE EITHER IN THE INTERIOR OR ALONG THE ADJACENT SEA BREEZE FRONT. WE WILL INCLUDE CHANCE POPS FOR SHOWERS/TSTMS. TEMPS ALOFT WILL BE 16-18C...SO MAX TEMPS SHOULD BE IN THE UPPER 80S AND AROUND 90. SATURDAY NIGHT... CONVECTION SHOULD DIMINISH. LIGHT WIND AND VERY HUMID AIR WILL PROMOTE FOGGY AREAS. MIN TEMPS WILL BE 65 TO 70...NEAR DEWPOINT. SUNDAY-MONDAY... COLD FRONT APPROACHES FROM THE WEST WITH INCREASING SOUTHWEST FLOW SURFACE AND ALOFT. 850 MB WINDS INCREASE TO 30-40 KNOTS. 500 MB WINDS ARE MORE MODEST SUNDAY AT 25 KNOTS BUT REACH 40-45 KNOTS BY MONDAY MORNING. MODELS SHOW A PRE- FRONTAL TROUGH TO OUR SOUTHWEST WHICH COULD SERVE AS A FOCUS FOR CONVECTION. WE WILL INCLUDE CHANCE POPS ACROSS ALL OF THE REGION SUNDAY AFTERNOON...SOONEST IN THE WEST AND LATE IN THE DAY TOWARD CAPE COD. PRECIPITABLE WATER VALUES ARE FORECAST AT 2.0 TO 2.25 INCHES...SO ANY SHOWERS/STORMS WILL CARRY POTENTIAL FOR HEAVY DOWNPOURS. TEMPS ALOFT 16-18C BUT WITH MORE CLOUDS SO A LITTLE LESS ON MAX TEMPS...GENERALLY 80S. CHANCE OF SHOWERS/TSTMS CONTINUES UNTIL THE COLD FRONT MOVES THROUGH ON MONDAY. THE BEST CHANCE OF PCPN OVERALL WILL COME WITH THE PASSAGE OF THE FRONT WHICH LOOKS TO BE ON MONDAY. WE HAVE LIKELY POPS WITH THIS EVENT ON MONDAY. TUESDAY-WEDNESDAY-THURSDAY... COLD FRONT STALLS SOUTH OF NEW ENGLAND. AIRMASS DEWPOINTS DRY A LITTLE...AND MOST OF THE DEEPER MOISTURE SHOULD BE SOUTH OF THE COAST. COULD BE SOME HIGH CLOUDS ALONG THE SOUTH COAST BUT OTHERWISE SHOULD BE RAIN FREE TUESDAY. LESS CERTAIN FOR WEDNESDAY AND THURSDAY AS THE NEXT SHORTWAVE AND SURFACE COLD FRONT APPROACH. MODELS SHOW POPS INCREASING TO EITHER CHANCE OR SLIGHT CHANCE WEDNESDAY-THURSDAY. WE WILL BRING CHANCE POPS TO THE SOUTH COAST AND SLIGHT CHANCE MOST OF THE REST OF THE FORECAST AREA. TEMPS ARE A BLEND OF LONG RANGE GUIDANCE. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT TAF CONFIDENCE...MODERATE. IFR/LIFR AROUND CAPE COD AND ISLANDS NOT EXPECTED TO MAKE MUCH MORE PROGRESS INLAND...PROBABLY ONLY TO S COASTAL MA. IFR WILL BE MORE LOCALIZED ACROSS INTERIOR WHERE PATCHY FOG FORMS...MAINLY INTERIOR SE MA. SHOULD SEE RAPID IMPROVEMENT TO VFR 10Z-13Z AREA WIDE. SCT TSTMS EXPECTED TO DEVELOP AFTER 17Z...MAINLY ALONG BDL-ORH-BOS CORRIDOR AND N WHICH WILL BRING LOCAL IFR IN HEAVY RAIN. STORMS SHOULD DIMINISH AFTER 21Z. RETURN OF PATCHY FOG/LOW CLOUDS THIS EVENING AROUND CAPE COD AND ISLANDS. OTHERWISE VFR TONIGHT. ANOTHER ROUND OF SCT TSTMS EXPECTED SAT. KBOS TAF...HIGH CONFIDENCE. LOW CLOUDS/FOG EXPECTED TO REMAIN S OF TERMINAL THROUGH DAYBREAK. INCLUDED VCTS GROUP FOR TIMING OF TSTMS. KBDL TAF...MODERATE CONFIDENCE. COULD SEE BRIEF MVFR IN FOG BEFORE DAYBREAK. INCLUDED VCTS GROUP FOR TIMING OF TSTMS. OUTLOOK...SUNDAY THROUGH TUESDAY... SUNDAY-MONDAY...MODERATE CONFIDENCE VFR CONDITIONS IN GENERAL BUT WITH SHOWERS/TSTMS POSSIBLE EACH DAY...EACH WITH A POTENTIAL FOR BRIEF MVFR-IFR CIGS/VSBYS. MAIN CONCERN ASIDE FROM LIGHTNING WOULD BE FOR HEAVY RAIN...ALTHOUGH SUNDAY-MONDAY THE CHANCE OF STRONG WIND GUSTS IN TSTMS WILL INCREASE. AREAS OF FOG EACH NIGHT WILL CREATE IFR-LIFR CONDITIONS ESPECIALLY CT VALLEY AND PVD-FMH- HYA- ACK. TUESDAY...MODERATE CONFIDENCE COLD FRONT STALL SOUTH OF NEW ENGLAND. MORNING FOG WITH AREAS OF IFR...OTHERWISE VFR WITH WEST WIND. && .MARINE... HIGH CONFIDENCE IN WINDS AND SEAS REMAINING BELOW SCA THROUGH FRIDAY NIGHT AS S/SW FLOW PREVAILS. THERE IS A LOW PROBABILITY OF WIND GUSTS NEAR 20 TO 25 KTS NEAR SHORE FRIDAY AFTERNOON. MAIN HAZARD IS LATE NIGHT AND EARLY MORNING DENSE FOG...MAINLY ON S COASTAL WATERS. SEAS WILL SLOWLY BUILD S OF NEW ENGLAND BUT UNDERCUT WAVEWATCH WHICH WANTS TO BRING 5 TO 6 FT SEAS INTO S COASTAL WATERS TODAY. OFFSHORE BUOYS NOT SHOWING MORE THAN 3 TO 5 FT THIS MORNING SO WE THINK THIS IS MORE REALISTIC. BEST CHANCE OF STORMS FRIDAY AFTERNOON IS ON NARRAGANSETT BAY...BOSTON HARBOR AND PERHAPS E MA COASTAL WATERS. OUTLOOK...SATURDAY THROUGH TUESDAY... LIGHT WINDS SATURDAY...THEN INCREASING SOUTHWEST WINDS SUNDAY AND MONDAY AHEAD OF AN APPROACHING COLD FRONT. GUSTS OF 20-25 KNOTS SUNDAY AND MONDAY WITH SEAS BUILDING 5-8 FEET ESPECIALLY ON THE OUTER WATERS AND RI WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED DURING SUNDAY AND MONDAY. AFTER THE COLD FRONT MOVES THROUGH ON MONDAY...WIND SHOULD SHIFT TO WEST AND DIMINISH. SEAS WILL SUBSIDE MONDAY NIGHT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR CTZ002-003. MA...AIR QUALITY ALERT FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR MAZ004>006-009>012-026. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...WTB/RLG |
| #531396 (Received by flhurricane at: 1:29 AM 03.Aug.2012) AFDCAR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 119 AM EDT FRI AUG 3 2012 .SYNOPSIS... A FRONTAL BOUNDARY WILL CROSS THE REGION THIS EVENING WITH THE POTENTIAL FOR FOG LATER TONIGHT INTO FRIDAY MORNING. A COLD FRONT WILL CROSS THE AREA ON FRIDAY WITH POSSIBLE THUNDERSTORMS. HIGH PRESSURE WILL RETURN FOR SATURDAY.&& .NEAR TERM /THROUGH TODAY/... UPDATE 0110L: ANY LINGERING SHOWERS HAVE DISSIPATED W/ NEXT ROUND OF ACTIVITY EXPECTED TO MOVE INTO WRN/NWRN AREAS BY ERLY AM. ADJUSTED POPS TO REFLECT THESE TRENDS AND ADJUSTED SKY COVER TO ACCOUNT FOR STRATUS WHICH COVERS THE SERN HALF OF THE FA ATTM... 10PM UPDATE... ADJUSTED POPS/WX/SKY FOR LATEST SATELLITE/RADAR TRENDS. MAY SEE THE SMALL AREA OF SHOWERS CURRENTLY JUST SOUTH OF DOVER-FOXCROFT HANG ON A FEW HOURS MORE. STILL EXPECT STRATUS TO CONTINUE TO SPREAD/DEVELOP NORTHWARD THROUGH MUCH OF THE NIGHT. PREV DISCUSSION... MAIN CHALLENGES THIS CYCLE WILL BE CONVECTION AND FOG. WIDELY SCATTERED TSTMS FIRING AHEAD OF THE APCHG FRONTAL BOUNDARY. LATEST LAPS/RUC SOUNDINGS SUGGESTING THE MAIN GIST W/THESE STORMS WILL BE HEAVY RAINFALL AND GUSTY WINDS INTO THE EVENING. IT APPEARS THAT THE STORMS WIND DIE DOWN W/LOSS OF HEATING AND FORCING WEAKENS. CLEARING SKIES FOR A TIME AND HUMID AIRMASS IN PLACE W/A SOUTHERLY FLOW WILL LEAD TO THE POTENTIAL FOR FOG FORMATION ONCE AGAIN LATER TONIGHT INTO FRIDAY MORNING ESPECIALLY IN AREAS THAT HAD RAINFALL AND ACROSS THE DOWNEAST AND THE COAST. STAYED W/THE MIDNIGHT CREW`S THINKING OF AREAS OF FOG FOR THE INTERIOR DOWNEAST AND COAST AND WENT W/PATCHY FOG FURTHER NORTH. THE EVENING AND MIDNIGHT CREW WILL NEED TO KEEP AN EYE ON THE FOG POTENTIAL ACROSS THE NORTH AND WEST FOR BEEFED WORDING. LATEST SREF INDICATES HIGHEST IMPACT ACROSS THE DOWNEAST AND COAST. OVERNIGHT LOWS WILL REMAIN IN THE 60S. FRIDAY COULD BE AN ACTIVE DAY IF THE TIMING IS RIGHT. CONVECTIVE TEMPERATURE SHOULD BE EASILY REACHED AS HIGH TEMPERATURES ARE FCST TO HIT INTO THE 80S W/THE EXCEPTION OF THE COAST AS A SSW FLOW WILL KEEP THE COAST COOLER. THE LATEST GFS AND NAM SOUNDINGS POINTED TO STEEPENING LAPSE RATES FROM 850-500 MBS OF UP TO 6.5 C/KM. LIS FCST TO DROP TO -4 TO -6 W/SBCAPES OF 1500-2000 JOULES. THE IMPRESSIVE THINGS TO NOTE ARE SWEAT INDEX HITS 300+ AND TOTAL TOTALS HIT AOA 50. ALL THIS WOULD POINT TO THE POTENTIAL OF SOME STORMS BECOMING STRONG TO POSSIBLY SEVERE. WBZS ARE SHOWN SHOWN TO DROP BACK TO BELOW 11K FT WHICH COULD SUPPORT HAIL. 0-6KM SHEAR IS AROUND 30 KTS TO BOOT. DECISION HERE WAS TO GO AHEAD TO ADD ENHANCED WORDING IN FOR GUSTY WINDS AND HAIL W/ANY TSTMS. MIDNIGHT CREW CAN ASSESS THIS FURTHER. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... ANY LINGERING SHOWERS OR STORMS WILL QUICKLY DIE DOWN FRIDAY EVENING AS THE COLD FRONT PUSHES SOUTH OF THE REGION AND HIGH PRESSURE BUILDS IN. LOWS FRIDAY NIGHT WILL RANGE FROM THE MID 50S IN THE NORTH TO AROUND 60 DOWNEAST. FOR SATURDAY, THE COLD FRONT SOUTH OF THE REGION WILL SLOWLY MOVE BACK TOWARD THE NORTH THROUGH THE DAY AS A WARM FRONT. THIS WILL RESULT IN MAINLY SUNNY SKIES IN THE MORNING GIVING WAY TO SOME MID AND HIGH LEVEL CLOUDS THROUGH THE AFTERNOON, ESPECIALLY OVER WESTERN SECTIONS. HIGHS WILL BE IN THE LOW TO MID 80S WITH DEW POINTS RANGING FROM THE UPPER 50S NORTH THE MID 60S SOUTH. AS THE WARM FRONT LIFTS NORTH THROUGH THE REGION SATURDAY NIGHT THIS COULD RESULT IN A FEW SHOWERS OVER WESTERN PARTS OF THE CWA. SUNDAY LOOKS TO FEATURE VERY WARM AND HUMID CONDITIONS UNDER VARIABLE SKIES WITH HIGHS IN THE MID 80 - EXCEPT AROUND 80 ALONG THE COAST. THERE WILL BE A CONTINUING CHANCE FOR A FEW SHOWERS OR THUNDERSTORMS. HOWEVER THE MOST WIDESPREAD AND ORGANIZED ACTIVITY LOOKS TO REMAIN OFF TO THE WEST THROUGH THE DAY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... THE SYSTEM WILL MOVE NORTH OF THE FORECAST AREA SUNDAY NIGHT INTO MONDAY, DRAGGING ITS ATTENDANT COLD FRONT ACROSS NEW ENGLAND AS IT DOES SO. AS SUCH, THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE LATE SUNDAY, BUT ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY. THIS FRONT WILL BE FOLLOWED BY A BRIEF RIDGE OF HIGH PRESSURE, BRINGING COOLER TEMPERATURES AND DRY WEATHER FOR MONDAY NIGHT AND TUESDAY. PRECIP CHANCES THEN INCREASE AGAIN BY MID WEEK AS ANOTHER FRONT MOVES INTO NORTHERN MAINE. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/... NEAR TERM: LOOKING FOR MVFR EARLY THIS EVENING GOING TO MVFR AND THEN IFR FOR ALL THE TERMINALS LATER TONIGHT INTO FRIDAY MORNING. KBGR AND KBHB COULD EVEN HIT LIFR FOR TIME FRIDAY MORNING. TSTMS DEVELOPING FRIDAY AFTERNOON COULD ALLOW FOR MVFR AND EVEN IFR FOR A BRIEF TIME. SHORT TERM: VFR GENERALLY EXPECTED THROUGH THE WEEKEND, BUT MVFR CONDITIONS WILL BE POSSIBLE IN MAINLY SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS SUNDAY. A PERIOD OF MVFR/IFR CONDITIONS IS LIKELY SUNDAY NIGHT INTO EARLY MONDAY AS A COLD FRONT CROSSES THE REGION BRINGING SHOWERS AND THUNDERSTORMS. && .MARINE... NEAR TERM: NO HEADLINES. MAIN CHALLENGE WILL BE THE CONTINUATION OF THE FOG INTO FRIDAY AND THE SWELL. RAN W/THE SWAN GUIDANCE OF 3-4 FT INTO FRIDAY WHICH WAS HANDLING THE CURRENT TRENDS WELL. A BLEND OF THE NAM12 AND GFS YIELDS 10-15 KTS AT BEST BY MIDDAY FRIDAY. SHORT TERM: WAVES WILL SUBSIDE FRIDAY NIGHT AND SATURDAY BEHIND THE FRONT AND REMAIN BELOW SCA LEVELS THROUGH SUNDAY AFTERNOON. SCA CONDITIONS WILL BE POSSIBLE FOR SUNDAY NIGHT INTO MONDAY. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...KHW/RUNYAN/HEWITT |
| #531395 (Received by flhurricane at: 1:09 AM 03.Aug.2012) AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 107 AM EDT FRI AUG 3 2012 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE WILL MOVE OVER THE AREA TONIGHT...THEN STALL AND WEAKEN FRIDAY. HIGH PRESSURE WILL EXTEND OVER THE AREA FROM OFFSHORE INTO NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1 AM FRIDAY...SHOWERS HAVE DISSIPATED INLAND AND HAVE REMOVED POPS FROM THE CURRENT FORECAST. OTHER THAN SOME SCATTERED TO BROKEN CLOUDS OVER THE FAR WESTERN CWA...SKIES ARE CLEAR OVER THE REMAINDER OF THE CWA. MIN TEMPERATURES SHOULD RANGE IN THE UPPER 60S AT THE COOLER INLAND SPOTS TO UPPER 70S ALONG THE IMMEDIATE COAST. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... AS OF 300 PM THU...MODELS AGREE ON SHRT WV STALL OVER AREA AND SHEARING OUT ON FRIDAY...WITH LITTLE CHANGE IN TYPICAL SUMMER-TIME SFC PATTERN. MODELS GENERALLY INDICATING LESS CONVECTIVE COVERAGE THAN TODAY...AND KEPT POPS AT 20% FOR FAVORED AREAS ALONG AND NW OF SEA BREEZE ZONE. MAX TEMPS SIMILAR TO TODAY...LOWER 90S INLAND AND UPR 80S COAST. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AS OF 315 PM THURS...CONTINUED WITH LITTLE CHANGES TO THE FORECAST OR FORECAST REASONING THROUGH THE LONG TERM. HIGH PRESSURE WILL BUILD BACK IN ALOFT FROM THE WESTERN ATLANTIC. THE BERMUDA HIGH ALSO STRENGTHENS OFFSHORE ALLOWING MOIST SOUTHERLY FLOW TO CONTINUE THROUGH THE EXTENDED. EXPECT ISOLATED TO SCATTERED DIURNAL CONVECTION INLAND AND ALONG THE SEA BREEZE BOUNDARY THROUGH THE WEEKEND. LOW LEVEL THICKNESSES WILL PERSIST AT 1415-1420 METERS...YIELDING TEMPS NEAR CLIMATOLOGY WITH HIGHS IN THE LOW/MID 90S INLAND TO 80S ALONG THE COAST. A FRONTAL BOUNDARY IS PROGGED TO APPROACH THE AREA FROM THE NORTHWEST MON WITH MOIST SOUTHWESTERLY FLOW AND INCREASING LOW LEVEL SHEAR AHEAD OF A ROBUST MID LEVEL SHORTWAVE. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE MON AFTERNOON/EVENING WITH PWATS AGAIN BUILDING ABOVE 2 INCHES. 12Z OPERATIONAL ECMWF AND GFS INDICATE THE FRONT WILL STALL JUST WEST OF THE REGION ACROSS THE CENTRAL PIEDMONT AND MID ATLANTIC STATES LATE MON THROUGH THURS WHILE AN UPPER TROUGH BECOME RE-ESTABLISHED ACROSS THE EASTERN CONUS. 00Z/12Z ECMWF SUGGEST A SURFACE LOW WILL FORM ALONG THE FRONT TUES NIGHT AND PUSH NE OFF THE MID ATLANTIC COAST WED INTO WED NIGHT. WILL MAINTAIN CHANCE POPS TUES THROUGH THURS WITH THE UPPER TROUGH AND STALLED SURFACE FRONT CONTINUING ACROSS THE REGION WHILE WEAK SHORTWAVES MOVE THROUGH THE FLOW ALOFT. LOW LEVEL THICKNESSES WILL REMAIN AROUND 1415 METERS MON THROUGH THURS HOWEVER GREATER CLOUD COVER AND PRECIP MAY MODERATE TEMPS FROM REACHING ABOVE THE 90 DEGREE MARK EACH DAY. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 18Z FRIDAY/... AS OF 105 AM FRIDAY...GIVEN NEARLY CALM WINDS AND MOSTLY CLEAR SKIES...IFR CONDITIONS IN FOG AND STRATUS ARE POSSIBLE LATER TONIGHT IN FOG. ANY FOG SHOULD DISSIPATE QUICKLY AFTER SUNRISE WITH VFR CONDITIONS EXPECTED THROUGH FRIDAY. LONG TERM /FRIDAY THROUGH TUESDAY/ AS OF 330 PM THURS...PREDOMINANT VFR AVIATION CONDITIONS EXPECTED THROUGH THE EXTENDED. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN DIURNAL CONVECTION EACH DAY. SOUTHWESTERLY SURFACE FLOW WILL PERSIST INTO EARLY NEXT WEEK. A FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST MON NIGHT INTO TUES WITH SHOWERS AND THUNDERSTORMS EXPECTED AHEAD OF AND ALONG THE BOUNDARY. && .MARINE... SHORT TERM /THROUGH FRIDAY/... AS OF 105 AM FRIDAY...GENERALLY LIGHT S/SW WINDS AT 10 KNOTS OR LESS CURRENTLY WITH SEAS 2 TO 3 FEET. THIS SHOULD CONTINUE OVERNIGHT WITH WINDS INCREASING AGAIN FRI AFTN...BUT SPEEDS REMAINING BELOW 15 KT. WW3 CONTINUES TO INITIALIZE ABOUT 1 FOOT TOO HIGH WITH SEAS OVER OUTER PORTIONS...AND LEANED TO PREVIOUS FCST AND SWAN DURING PERIOD FOR HEIGHTS MAINLY 2-3 FT. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/ AS OF 330 PM WED...GOOD BOATING CONDITIONS EXPECTED SAT AND SUN WITH THE BERMUDA HIGH STRENGTHENING OVER THE WESTERN ATLANTIC BRINGING SLY WINDS ACROSS THE WATERS. SPEEDS WILL RANGE GENERALLY 10-15 KNOTS WITH SEAS 2 TO 3 FT. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THE WEEKEND AS WELL. GRADIENT BEGINS TO TIGHTEN LATE SUN AND MON AS FRONTAL SYSTEM APPROACHES FROM THE NW AND EXPECT WINDS TO INCREASE TO AROUND 15-20 KT...MAINLY ACROSS THE NORTHERN AND CENTRAL WATERS. SEAS BUILD ACCORDINGLY TO AROUND 3-5 FT SUN NIGHT TROUGH MON FROM DIAMOND SHOALS NORTH...BUT REMAIN 2 TO 4 FT FOR THE SOUTHERN WATERS. SWAN APPEARED OVERDONE FOR MON INTO TUES SO HEDGED TOWARDS PREVIOUS WAVE FORECAST WITH MINOR TWEAKS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ |
| #531394 (Received by flhurricane at: 1:09 AM 03.Aug.2012) AFDLCH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 1156 PM CDT THU AUG 2 2012 .DISCUSSION... THE AFOREMENTIONED WARM DOME OF HIGH PRESSURE ACROSS CENTRAL TEXAS WILL BUILD INTO THE MISSOURI-ILLINOIS REGION ON FRIDAY. THE TRACK OF TRAVELING IMPULSES ALOFT...MENTIONED BELOW...WILL SHIFT SLIGHTLY EASTWARD...WITH ITS ASSOCIATED RAIN CHANCES SLIGHT AS WELL. && .PREV DISCUSSION... /ISSUED 1001 PM CDT THU AUG 2 2012/ DISCUSSION... AREA RADARS SHOW SOME ISOLATED SHOWERS MOVING SW INTO CNTL LA...AND A FEW LOCATIONS OVER THE FAR NE PORTIONS OF THE CWA COULD SEE A SPRINKLE OR TWO AS IT CONTINUES WEAKENING THIS EVENING. WITH THIS IN MIND...TWEAKED POPS UP SLIGHTLY...BUT KEPT AS SILENT 10S AS ACTIVITY IS EXPECTED TO REMAIN QUITE ISOLATED AND SHOULD BE GONE WITHIN THE NEXT HOUR OR TWO. OTHERWISE...WARM MUGGY CONDITIONS SHOULD PERSIST TONIGHT INTO TOMORROW AS UPPER LEVEL RIDGING REMAINS THE DOMINANT WEATHER FEATURE. COULD SEE A FEW SHOWERS OVER OUR ERN ZONES TOMORROW AFTN...WITH SHOWER CHANCES CREEPING UPWARD GOING INTO THE WEEKEND AS THE UPPER RIDGE STARTS TO WEAKEN OVER THE AREA. CURRENT FCST IS ON TRACK AND NO UPDATE PLANNED THIS EVENING. 24 PREV DISCUSSION... /ISSUED 620 PM CDT THU AUG 2 2012/ DISCUSSION... A WARM DOME OF HIGH PRESSURE...ITS MEAN POSITION ACROSS CENTRAL TEXAS...WILL DRIFT WESTWARD OVER THE NEXT FEW DAYS. IMPULSES ALOFT...EMANATING FROM A STALLED FRONTAL SYSTEM EXTENDING THROUGH KANSAS CITY TO THE GREAT SMOKEY MOUNTAINS...WILL TRAVEL SOUTHWARD AROUND THE OUTER EASTERN PERIPHERY OF DOME. THESE TRAVELING IMPULSES WILL BRING ABOUT PATCHY CIRRUS ACROSS SOUTH CENTRAL AND EAST CENTRAL LOUISIANA...THINNING AS YOU MOVE WESTWARD. HOWEVER...CONVECTIVE ACTIVITY IS NOT EXPECTED TONIGHT. JT PREV DISCUSSION... /ISSUED 406 PM CDT THU AUG 2 2012/ DISCUSSION...SCATTERED TO BROKEN CU CURRENTLY ACROSS THE AREA...WITH SOME MID AND UPPER LEVEL CLOUDINESS SLIDING SOUTH ACROSS THE EASTERN PORTION OF THE AREA. RADAR DEPICTING A FEW SHOWERS OVER ACADIANA AND A FEW TRYING TO DEVELOP FURTHER WEST. BULK OF OBSERVATIONS SHOWING TEMPS IN THE LOW TO MID 90S...YIELDING A HEAT INDEX FROM 100-105. STRONG MID/UPPER LEVEL HIGH REMAINS MEANDERING ABOUT MID-TEXAS WITH TROFFING OVER THE SOUTHEAST CONUS. THIS YIELDING A PREDOMINANT DRY NORTHERLY FLOW FOR US...BUT CONTINUE TO SEE SOME WEAK DISTURBANCES ADVANCING SOUTH ACROSS THE AREA BRINGING BOUTS OF INCREASED CLOUDINESS AND SHOWERS. FRIDAY AND SATURDAY...SIMILAR PATTER EXPECTED TO HOLD OVER THE NEXT FEW DAYS MAINTAINING LIMITED RAIN CHANCES WHILE TEMPERATURES WILL CONTINUE TO BE SEASONABLY UNCOMFORTABLE...BUT WILL REMAIN BELOW HEAT INDEX CRITERIA. SUNDAY AND MONDAY....MODELS INDICATING HEIGHT FALLS ACROSS THE AREA AS LOW/TROF TRACKS EAST ACROSS THE NORTHERN PLAINS AND DIGS SOUTHWARD AS IT ADVANCES INTO THE EASTERN CONUS. THIS OCCURRING AS INVERTED GULF TROF MIGRATES WEST. FORECAST SOUNDINGS CLOSING IN ON 2 STANDARD DEVIATIONS ABOVE THE NORM. HAVE BUMPED UP POPS ACCORDINGLY AND WOULD NOT BE SURPRISED TO SEE HIGHER POPS DOWN THE ROAD. TUESDAY ON...ECMWF TRENDING TOWARD A DRIER FORECAST...BUT LESS SO WITH THE GFS AS WEAKNESS REMAINS OVER THE AREA. AT THIS TIME HAVE SIMPLY TRENDED POPS DOWN THROUGH THE REMAINDER OF THE FORECAST. OTHERWISE...WILL CONTINUE TO WATCH THE PROGRESSION OF ERNESTO. MARINE...SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE ACROSS THE NORTHERN GULF OF MEXICO FROM THE WESTERN ATLANTIC. THIS WILL KEEP MAINLY ONSHORE FLOW AND RELATIVELY LOW SEAS INTO THE NEW WEEK. 23 && .PRELIMINARY POINT TEMPS/POPS... KLCH 78 94 77 94 77 / 10 10 10 20 20 KBPT 78 93 77 94 77 / 0 10 10 20 20 KAEX 76 95 76 96 75 / 10 20 10 20 20 KLFT 78 94 77 94 76 / 10 20 10 30 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ |
| #531393 (Received by flhurricane at: 1:08 AM 03.Aug.2012) AFDCHS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 102 AM EDT FRI AUG 3 2012 .SYNOPSIS... ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THE WEEK...WHILE A TROUGH OF LOW PRESSURE PERSISTS INLAND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... DEBRIS CLOUDINESS IS QUICKLY DIMINISHING AND SHOULD SEE CLEAR TO MOSTLY CLEAR SKIES PREVAIL. THERE ARE INDICATIONS THAT SOME STRATUS COULD DEVELOP ACROSS THE CSRA AND FAR WESTERN AREAS PRIOR TO SUNRISE. GUIDANCE IS OFFERING MIXED SIGNALS ON HOW WIDESPREAD THE STRATUS WILL BECOME...BUT WILL SHOW SKIES BECOMING PARTLY CLOUDY ACROSS THE FAR WEST TO TREND. PATCHY FOG WILL BE POSSIBLE ESPECIALLY WHERE RAINS FELL EARLIER IN THE DAY. WIDESPREAD DENSE FOG IS NOT EXPECTED AT THIS TIME. && .SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/... A TYPICAL SUMMERTIME PATTERN WILL PRESENT ITSELF THIS WEEKEND AS ATLANTIC HIGH PRESSURE EXPANDS OVER THE SOUTHEAST WHILE MID LVL RIDGING MAINTAINS A STRONG HOLD OVER THE CENTRAL UNITED STATES. WITH THESE SYNOPTIC FEATURES IN PLACE...LIGHT ONSHORE FLOW WILL PERSIST THIS WEEKEND AND RESULT IN FAVORABLE CONDITIONS FOR AN INLAND MOVING SEABREEZE EACH AFTERNOON ALONG WITH PULSE TYPE SHOWERS/THUNDERSTORMS THROUGH EACH EVENING. ACTIVITY WILL LIKELY DIMINISH QUICKLY WITH SUNSET EACH EVENING GIVEN WEAK MID/UPPER LVL SUPPORT. ALTHOUGH AN ISOLATED STRONG STORM IS POSSIBLE WITH THIS PULSE TYPE CONVECTION AND BOUNDARY INTERACTIONS...THE OVERALL SEVERE WEATHER THREAT WILL REMAIN LOW OVER THE PERIOD. IN GENERAL...HAVE MAINTAINED A 20 POP FORECAST FOR FRIDAY...WITH AN INCREASING TREND TO 20-30 POPS ON SATURDAY AND SUNDAY AS PWATS APPROACH 2 INCHES OVER THE REGION. HIGHEST CHANCES OF PRECIP SHOULD OCCUR OVER INLAND AREAS ALONG AND AHEAD OF THE AFTERNOON SEABREEZE. ACTIVITY WILL REMAIN DIURNAL IN NATURE GIVEN WEAK MID/UPPER LVL SUPPORT. THE OVERALL SEVERE WEATHER THREAT WILL ALSO REMAIN LOWER THAN PREVIOUS DAYS. OVERALL TEMPS WILL REMAIN A DEGREE OR TWO ABOVE CLIMATOLOGY...WITH 1000-850 THICKNESS VALUES SUPPORTING HIGHS IN THE LOW 90S. OVERNIGHT LOWS WILL BE IN THE LOW/MID 70S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... MODELS SHOW SUBTLE HIGH FALLS AT THE BEGINNING OF THE PERIOD AS A LOW PRESSURE SYSTEM MOVES EASTWARD ACROSS THE NEW ENGLAND AREA. ITS ASSOCIATED COLD FRONT WILL LIKELY STALL OUT WELL NORTH OF THE AREA SOMETIME AROUND MID WEEK. MEANWHILE...THE UPPER RIDGE ACROSS CENTRAL UNITED STATES WILL CONTINUE TO STRENGTHEN THROUGH THE PERIOD. AT THE SURFACE...THE FORECAST AREA WILL REMAIN SANDWICHED BETWEEN THE SURFACE HIGH PRESSURE OVER THE MIDDLE OF THE UNITED STATES AND THE SUBTROPICAL HIGH JUST TO THE EAST. THIS PATTERN COULD ALLOW FOR AN INCREASE IN CONVECTION...ESPECIALLY AS CONVECTION DEVELOPS ALONG THE STALLED FRONT AND INTERACTS WITH OTHER BOUNDARIES...LIKE THE SEA BREEZE. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS WITH LOW TO MID 90S EXPECTED DURING THE AFTERNOON AND DIPPING INTO THE LOW TO MID 70S OVERNIGHT. && .AVIATION /05Z FRIDAY THROUGH TUESDAY/... VFR THROUGH FRIDAY. LOW PROBABILITIES FOR GROUND FOG LATE TONIGHT AND FOR TSTMS FRIDAY AFTERNOON. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER THAN 30 PERCENT CONFIDENCE LEVEL AT THIS TIME. && .MARINE... THE PRESSURE PATTERN REMAINED WEAK OVER COASTAL WATERS DUE TO EARLIER THUNDERSTORMS...SUPPORTING LIGHT/VARIABLE WINDS. 00Z NAM GUIDANCE SUGGESTS THAT THE S/SW GRADIENT SHOULD REDEVELOP OVERNIGHT...ACCOMPANIED BY SOME INCREASE IN WIND SPEEDS. HOWEVER... WINDS SHOULD GENERALLY REMAIN 15 KT OR LESS. ATLANTIC HIGH PRESSURE WILL EXPAND OVER THE WATERS THIS WEEKEND... LEADING TO CONDITIONS WELL BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO EARLY NEXT WEEK. IN GENERAL...SOUTH WINDS BETWEEN 10-15 KT WILL PERSIST ON THE WESTERN SIDE OF THE ATLANTIC RIDGE WITH HIGHEST WINDS EXPECTED NEAR INLAND MOVING SEABREEZE CIRCULATIONS AND EARLY NIGHT SURGES. WINDS MAY BRIEFLY BECOME SOUTHEAST EACH AFTERNOON/EVENING AS THE SEABREEZE MAKES WAY INLAND. SEAS WILL REMAIN BETWEEN 1-3 FEET...WITH SWELLS FROM THE SOUTH/SOUTHEAST. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$ |
| #531392 (Received by flhurricane at: 1:00 AM 03.Aug.2012) AFDCRP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1150 PM CDT THU AUG 2 2012 .DISCUSSION...UPDATED FOR THE 06Z AVIATION DISCUSSION. && .AVIATION...VFR THROUGH THE TAF PERIOD. WINDS AT LRD SHOULD BEGIN TO DIMINISH OVER THE NEXT COUPLE OF HOURS. WINDS WILL GRADUALLY STRENGTHEN AND SHIFT MORE OUT OF THE SOUTH BY THE LATE MORNING AT ALI/CRP/VCT...WITH WINDS STRENGTHENING AT LRD IN THE AFTERNOON. A SHIFT OUT OF THE SOUTHEAST WILL OCCUR ALONG THE COASTAL LOCATIONS FROM CRP TO ALI. DID INCREASE WIND GUSTS IN THE AFTERNOON TO 25 KTS AS THE SURFACE PRESSURE GRADIENT TIGHTENS. OTHERWISE...WINDS WILL ONCE AGAIN DECOUPLE FROM EAST TO WEST THROUGH THE EVENING HOURS. FEW TO SCATTERED CLOUDS WILL BE POSSIBLE DURING THE MORNING HOURS AS ADDITIONAL LOW LEVEL MOISTURE MOVES INTO THE REGION. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 77 97 78 98 78 / 10 10 10 10 10 VICTORIA 75 96 76 96 76 / 0 0 0 20 10 LAREDO 79 105 80 104 80 / 0 0 0 0 10 ALICE 75 102 77 101 77 / 0 0 0 10 10 ROCKPORT 80 91 81 92 82 / 10 10 10 20 10 COTULLA 75 103 76 103 75 / 0 0 0 0 10 KINGSVILLE 76 99 78 99 78 / 0 0 0 10 10 NAVY CORPUS 80 91 81 92 81 / 10 10 10 20 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531390 (Received by flhurricane at: 12:47 AM 03.Aug.2012) AFDHGX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 1140 PM CDT THU AUG 2 2012 .AVIATION... OTHER THAN BRIEF PERIODS OF MVFR CEILINGS POSSIBLE AWAY FROM THE BIG AIRPORTS AFTER SUNRISE...EXPECT VFR CONDITIONS TO CONTINUE. WIND SPEEDS MAY APPROACH 15 KNOTS FRIDAY AFTERNOON AT KCLL. 40 && .PREV DISCUSSION... /ISSUED 925 PM CDT THU AUG 2 2012/ DISCUSSION... SOME SHRA OVER WEST CENTRAL LOUISIANA CONTINUE TO HOLD TOGETHER AS THEY MOVE SOUTH-SOUTHWEST. DON`T THINK THESE SHRA WILL HOLD TOGETHER BUT IT IS IN AN AREA OF DEEPER MOISTURE THAT IS EDGING GRADUALLY WESTWARD. UPPER LEVEL RIDGING IS STILL THE DOMINANT WEATHER FEATURE AND AM EXPECTING WARM AND HUMID WEATHER TO PERSIST TOMORROW WITH SLIGHTLY COOLER TEMPS ON SATURDAY AS THE UPPER LEVEL RIDGE RETREATS AND DEEPER MOISTURE MOVES INTO SE TX. PREVIOUS FCST HAS THIS COVERED SO NOT PLANNING AN UPDATE THIS EVENING. AS FOR THE TROPICS...ERNESTO IS MOVING WEST AT 22 MPH. THIS STORM IS LOOKING A BIT BETTER ON SATELLITE THIS EVENING. THE ECMWF DOES NOT DEVELOP MUCH...WHILE THE 18Z GFS KEEPS THE SYSTEM WEAK AND WELL SOUTH OF SE TX. STILL A GREAT DEAL OF UNCERTAINTY. KEEP UP WITH THE FORECASTS THIS WEEKEND. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 77 98 76 97 75 / 0 0 0 10 10 HOUSTON (IAH) 78 96 77 95 76 / 0 0 0 20 20 GALVESTON (GLS) 83 92 81 92 81 / 10 10 10 20 20 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ |
| #531389 (Received by flhurricane at: 12:42 AM 03.Aug.2012) AFDLIX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW ORLEANS LA 1138 PM CDT THU AUG 2 2012 .AVIATION... VFR CONDITIONS TO PREVAIL ALL TERMINALS NEXT 24 HOURS. CONVECTION SHOULD BE ONCE AGAIN LIMITED IN COVERAGE BUT WILL INCLUDE PROB30 GROUPS FOR SEA BREEZE PRONE LOCATIONS WHERE BEST FOCUS WILL EXIST MAINLY AFTER 21Z. 24/RR && .PREV DISCUSSION... /ISSUED 854 PM CDT THU AUG 2 2012/ SOUNDING DISCUSSION... NO PROBLEMS WITH THE FLIGHT THIS EVENING. A FAIRLY MOIST SOUNDING WITH PLENTY OF INSTABILITY AND HIGH CAPE VALUES WITH A PW OF 2.07 INCHES...AN LI OF -8.1 AND A CAPE OF AROUND 4700. ALTHOUGH A PW OF 2.07 INCHES...A FAIRLY DRY LAYER BETWEEN 700 AND 900 MB HELPING INHIBIT MUCH IN THE WAY OF WIDESPREAD SHOWER AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING. A LIGHT WEST...SOUTHWESTERLY FLOW IN THE LOWER LEVELS UP TO AROUND 750 MB WITH A NORTH...NORTHWESTERLY FLOW IN THE MIDDLE LEVELS AND A NORTHEASTERLY FLOW IN THE UPPER LEVELS. PREV DISCUSSION... /ISSUED 348 PM CDT THU AUG 2 2012/ SYNOPSIS... HIGH PRESSURE STILL CENTERED OVER THE GULF OF MEXICO WITH A WEAK FRONTAL BOUNDARY LOCATED WELL TO THE NORTH OF THE LOCAL AREA OVER THE MIDDLE MISSISSIPPI VALLEY. A WEAK TROPICAL WAVE IS LOCATED OVER THE WESTERN CARIBBEAN AND TROPICAL STORM ERNESTO IS LOCATED A FEW HUNDRED MILES EAST OF THE WINDWARD ISLANDS. SHORT TERM... WELL...THE DRY AIR THAT HAD MOVED INTO THE AREA YESTERDAY AFTERNOON HAS ALREADY DISAPPEARED. A FEW PLACES SAW HEAT INDEX VALUES IN THE 105 TO 108 DEGREE RANGE THIS AFTERNOON...BUT LUCKILY IT HAS ONLY BEEN A COUPLE HOURS. TOMORROW LOOKS TO BE SIMILAR...ONCE AGAIN FORECASTING CONDITIONS THAT ARE BORDERLINE FOR A HEAT ADVISORY. BOTH LOWS AND AFTERNOON HEAT INDEX VALUES WILL BE VERY NEAR THE LOCAL THRESHOLDS. NOT VERY CONFIDENT AS TO WHETHER CONDITIONS WILL EXCEED CRITERIA OR STAY JUST BELOW. SO WITH THAT SAID...GOING TO PUNT THE HEAT ADVISORY DECISION TO THE NIGHT SHIFT AS THEY WILL BE ABLE TO SEE WHAT THE OVERNIGHT TEMPERATURES ARE ACTUALLY DOING COMPARED TO THE FORECAST. EITHER WAY...IT WILL STILL FEEL HOT DURING THE AFTERNOON HOURS...SO ANYONE WITH PLANS TO WORK OUTSIDE SHOULD BE SURE TO STAY HYDRATED AND TAKE BREAKS IN THE SHADE IF POSSIBLE. ISOLATED TO POSSIBLY SCATTERED CONVECTION MAY PROVIDE SOME RELIEF FROM THE HEAT. HIGHER CHANCES OF RAIN WILL BE ACROSS EXTREME EASTERN PORTIONS OF THE AREA THAT ARE CLOSER TO THE EDGE OF THE HIGH. BY SATURDAY...HIGH PRESSURE WILL BEGIN TO SHIFT WESTWARD WHICH WILL RESULT IN SLIGHTLY HIGHER POPS. THE SCATTERED CONVECTION AND OUTFLOW BOUNDARIES SHOULD HELP LIMIT AFTERNOON TEMPERATURES AND HELP BRING HEAT INDEX VALUES DOWN. LONG TERM... HIGH PRESSURE CONTINUES TO SLIDE WESTWARD AS AN UPPER LEVEL TROUGH MOVES THROUGH THE MIDDLE MISSISSIPPI VALLEY. WITH THE LOCAL AREA ON THE PERIPHERY OF THE UPPER LEVEL RIDGE...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP EACH DAY. WITHOUT THE STAGNANT CONDITIONS OF THE DEEP RIDGE...ALSO EXPECT LOWS TO COOL OFF A BIT MORE OVERNIGHT WITH TEMPS DROPPING CLOSER TO CLIMATOLOGY. EXPECT LOWS IN THE LOW TO MID 70S ACROSS MOST OF THE REGION THROUGH NEXT WEEK WITH HIGHS GENERALLY IN THE LOW 90S. MEANWHILE...ALL EYES WILL REMAIN ON TROPICAL STORM ERNESTO. ERNESTO IS CURRENTLY FORECAST TO MAINTAIN ITS PRESENT WEST/NORTHWESTWARD MOTION FOR THE NEXT FIVE DAYS. IT IS FORECAST TO STRENGTHEN SLOWLY OVER THE WEEKEND AND BECOME A WEAK HURRICANE BY MONDAY AFTERNOON. THERE IS SOME UNCERTAINTY CONCERNING THE EVENTUAL TRACK OF ERNESTO AND HOW FAR NORTH IT WILL EVENTUALLY MOVE AFTER EMERGING INTO THE GULF OF MEXICO. HOWEVER...MOST OF THE CURRENT MODEL GUIDANCE FORECASTS A LANDFALL SOMEWHERE ALONG THE SOUTH TEXAS OR MEXICO COAST LATE NEXT WEEK OR NEXT WEEKEND. WE WILL DEFINITELY BE KEEPING AN EYE ON IT BUT AT THE PRESENT TIME...ERNESTO DOES NOT APPEAR TO BE A THREAT TO THE LOCAL AREA. AVIATION... THERE IS TOO MUCH UNCERTAINTY TO INCLUDE MENTION OF TSRA IN THE TAFS THIS AFTERNOON...HOWEVER...WILL WATCH FOR ANY BOUNDARY INTERACTIONS FROM ALABAMA...THE COASTAL WATERS...AND LAKE AND SEABREEZES THAT COULD CAUSE TSRA DEVELOPMENT FROM KGPT TO KASD TO KHUM. THERE COULD BE BRIEF PERIODS OF MVFR DUE TO CIGS THROUGH 19Z...OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY MARINE... A BROAD RIDGE OF HIGH PRESSURE ACROSS THE NORTH GULF WILL PREVAIL THROUGH SATURDAY AND SLOWLY MOVE WESTWARD BEGINNING SUNDAY. WITH A WEAK GRADIENT ACROSS THE AREA...EXPECT WINDS TO REMAIN GENERALLY 10 KTS OR LESS AND SEAS/WAVES MOSTLY NEAR 1 FOOT THROUGH TUESDAY. DECISION SUPPORT... DSS CODE...GREEN. DEPLOYED...NONE. ACTIVATION...NONE. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE $$ |
| #531388 (Received by flhurricane at: 12:41 AM 03.Aug.2012) AFDGYX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAY ME 1233 AM EDT FRI AUG 3 2012 .SYNOPSIS... A COLD FRONT WILL APPROACH NEW ENGLAND FROM THE NORTHWEST FRIDAY...AND THEN STALL OVER THE REGION ON SATURDAY. LOW PRESSURE WILL TRACK THROUGH SOUTHERN CANADA SUNDAY...BEFORE DRAGGING A COLD FRONT THROUGH OUR REGION ON MONDAY. A WEAK AREA OF HIGH PRESSURE WILL FOLLOW DURING THE MIDWEEK PERIOD. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... 1225 AM...MINOR UPDATE TO ADJUST 1ST PERIOD SKY COVER AND HOURLY TEMPERATURE GRIDS. UPDATE...QUICK UPDATE TO KEEP TEMPS AND POPS. DIGITAL PRODUCTS ISSUED. PREV DISC...A WEAK UPPER LEVEL DISTURBANCE WILL MOVE FROM EASTERN NEW YORK STATE THIS AFTERNOON THROUGH NEW ENGLAND THIS EVENING. DEWPOINTS ACROSS THE REGION ARE PRIMARILY IN THE UPPER 60S...WITH SOME LOCATIONS REPORTING IN THE LOWER 70S. WITH ABUNDANT LOW LEVEL MOISTURE AND WEAK UPPER LEVEL SUPPORT...WE SHOULD SEE SHOWERS AND THUNDERSTORMS DEVELOP ACROSS THE REGION THIS AFTERNOON. ALREADY SOME CONVECTION FIRING OVER THE MOUNTAINS. MODIFIED 12Z KGYX SOUNDING FOR A TEMPERATURE OF 81F DEGREES OVER A 68F DEGREE DEWPOINT RESULTED IN CAPE VALUES AROUND 2000J/KG. PWAT VALUES ON THEM MODIFIED SOUNDING UP AROUND 1.7 INCHES. STEERING FLOW LOOKS TO BE FROM THE WEST NORTHWEST AT ABOUT 20KTS. THIS IS SOMEWHAT OF A GOOD THING AS HEAVY RAINERS WILL BE POSSIBLE BUT AT LEAST THEY SHOULD BE MOVING. FREEZING LEVEL IS DOWN AROUND 12K FEET...SO SOME HAIL MAY ALSO BE POSSIBLE. EXPECT STORMS TO REMAIN BELOW SEVERE CRITERIA FOR THE MOST PART...BUT AN ISOLATED SEVERE STORM MAY BE POSSIBLE. ONCE THE STORMS SUBSIDE AROUND SUNSET...EXPECT AT LEAST PATCHY FOG TO SET UP ACROSS THE ENTIRE CWA. COASTAL LOCATIONS MAY SEE SOME MORE WIDESPREAD AND THICKER FOG. && .SHORT TERM /7 AM THIS MORNING THROUGH 6 AM SATURDAY/... DAY STARTS OFF WITH FOG IN THE MORNING. ONCE THE FOG BURNS OFF EXPECT TEMPERATURES TO CLIMB INTO THE 80S FAIRLY QUICKLY IN SOUTHWEST FLOW. AN APPROACHING COLD FRONT SHOULD PROVIDE ENOUGH INSTABILITY IN THE AFTERNOON TO SPARK SHOWERS AND THUNDERSTORMS...MAINLY OVER THE MOUNTAINS. && .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGH PRES RETREATS TO THE NE WHILE A WRM FNT PUSHES NE INTO THE REGION ON SATURDAY. THIS BRINGS VERY WARM, HUMID AND UNSTABLE AIR WHICH WILL KICK OFF ISOLD TO SCT SHRA AND TSTMS. CONVECTIVE ACTIVITY DIES DOWN AT NGT BUT REGENERATES ON SUNDAY UNDER THE VERY WARM AND HUMID AIR MASS AS A CD FNT APPROACHES FROM THE W IN ASSOCIATION WITH AN UPR LVL TROF. TEMPS ON SATURDAY COULD PUSH 90 OR A BIT HIGHER OVER INTERIOR SECTIONS OF SRN NH AND SW ME WHILE COASTAL AREAS ARE COOLED SOMEWHAT BY A SEA BREEZE AND ONSHORE SOUTHERLY FLOW. SUNDAY TEMPS NOT QUITE AS HOT WITH MORE SHRA ACTIVITY AROUND. THE UPR LVL TROF PUSHES E SWINGING THE CD FNT ACROSS THE REGION LATE SUNDAY NGT INTO MONDAY. THIS WILL RESULT IN SHRA AND TSTMS WHICH SHOULD BE CLEARING OUT ON MONDAY. THE TIMING WILL DEPEND ON HOW FAST THE FNT MOVES. ALSO...DEPENDING ON TIMING THERE COULD BE STRONG TSTMS WITH THIS FNT SUNDAY AFTERNOON INTO SUNDAY NGT. FAIR WX WITH LOWER HUMIDITY BUT ONLY SLIGHTLY LOWER DAYTIME TEMPS MOVES IN BEHIND THE FNT...STARTING LATE MONDAY AND LASTING THRU TUESDAY. AN UPR LVL TROF SWINGING SE FROM CANADA AND STRENGTHENING SOMEWHAT ALONG WITH A SFC TROF WILL HELP FOCUS ISOLD TO SCT SHRA AND TSTMS WEDNESDAY THRU THURSDAY. GENERALLY USED GFS40...HPC QPF AND BLEND OF MAV/MET MOS FOR SATURDAY AND SATURDAY NGT. FOR REST OF THE LONG TERM FCST USED GMOS...EXCEPT USED A BLEND OF GFS40, HPC GUIDANCE AND MEX MOS GUIDANCE FOR MAX AND MIN TEMPS. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SHORT TERM...VFR CONDITIONS TODAY WILL DETERIORATE TO IFR/LIFR TONIGHT IN FOG. THIS WILL BE ESPECIALLY TRUE FOR SITES ALONG THE COAST. FOG SHOULD BURN OFF TOMORROW MORNING WITH VFR CONDITIONS RETURNING. LONG TERM /SATURDAY THROUGH TUESDAY/...ISOLD TO SCT SHRA AND TSTMS COULD PRODUCE MVFR OR LOCALLY IFR CONDITIONS ON SATURDAY WITH A BETTER CHC FOR SHRA AND TSTMS AND MVFR TO IFR CONDITIONS ON SUNDAY. IFR SUNDAY NGT INTO MONDAY WITH A CD FNT BRINGING SHRA AND TSTMS. MOSTLY FAIR WX AND VFR CIG/VSBY LATE MONDAY THRU TUESDAY. && .MARINE... SHORT TERM...NO FLAGS EXPECTED. LONG TERM /SATURDAY THROUGH TUESDAY/...INCREASING SOUTHERLY FLOW OVER THE WEEKEND HAS A GOOD CHC OF REACHING SCA LEVELS ON SUNDAY AND SUNDAY NGT AS A CD FNT BEARS DOWN FROM THE NW CAUSING THE SFC PRES GRADIENT TO TIGHTEN. SEAS SHOULD ALSO BUILD INTO SCA LEVELS. WINDS AND SEAS EASE UP AFTER THE CD FNT MOVES THRU ON MONDAY. HIGH PRES KEEPS WINDS AND SEAS BELOW SCA LEVELS MONDAY NGT AND TUESDAY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ ES |
| #531387 (Received by flhurricane at: 12:30 AM 03.Aug.2012) AFDMOB AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOBILE AL 1128 PM CDT THU AUG 2 2012 .AVIATION...(03.06 UTC CYCLE)...LATEST SATELLITE AND SURFACE OBSERVATIONS SHOW THE PERIOD BEGINS WITH HIGH LEVEL CIRRUS CLOUDS ADVECTING SOUTHWARD IN THE DEEP LAYER MEAN WIND FLOW FOR THE REMAINDER OF TONIGHT AND TOMORROW WITH LIGHT SOUTHWESTERLY WINDS. VFR CONDITIONS PREVAIL THROUGH MOST OF UPCOMING TAF PERIOD AT REGIONAL TERMINAL SITES. AN ISOLATED THUNDERSTORM OR TWO MAY FORM IN THE VICINITY OF KPNS AND KBFM AFTER 09 UTC DUE TO EARLY MORNING FRICTIONAL CONVERGENCE FORMED BY A LIGHT SOUTHWEST SURFACE WIND FLOW ONTO LAND. EXPECT OCCASIONAL IFR CONDITIONS DUE TO CIGS/VSBYS IN SCATTERED THUNDERSTORMS MAINLY AFTER 15 UTC TOMORROW. ALTHOUGH THUNDERSTORMS WILL BE FORMING OVER LAND WHILE MOVING SOUTH DURING THE LATE MORNING AND EARLY AFTERNOON HOURS...THE ENHANCEMENT OF THUNDERSTORMS ALONG THE COAST DUE TO THE SEABREEZE WILL PROVIDE SLIGHTLY MORE COVERAGE ACROSS COASTAL TERMINALS. /23 JMM && .MOB WATCHES/WARNINGS/ADVISORIES... AL...NONE. FL...NONE. MS...NONE. GM...NONE. && $$ |
