AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 329 AM EDT THU MAY 12 2011 .SYNOPSIS... HIGH PRESSURE AT THE SURFACE AND ALOFT WILL BUILD INTO THE REGION THROUGH FRIDAY MORNING. LOW PRESSURE AND AN ASSOCIATED FRONTAL SYSTEM WILL AFFECT THE EASTERN CAROLINAS LATE FRIDAY AND OVER THE WEEKEND...AND THEN LINGER NEAR THE AREA THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM THURSDAY...UPPER RIDGE WHICH HAS BEEN SITUATED TO OUR W FOR MANY DAYS AND HAS HELPED TO STEER CONVECTION ACROSS THE CAROLINAS WILL SHIFT E AND ACROSS THE AREA THROUGH THE PERIOD. AT THE SURFACE...HIGH PRESSURE WILL SHIFT S AND E OF THE AREA THROUGH TONIGHT. STILL...EVEN WITH THIS WE WILL HAVE CONSIDERABLE CLOUDS AROUND TODAY AS SUBSIDENCE WILL BE WEAK AT BEST. MOISTURE PROFILES SHOW A GOOD DEAL OF MOISTURE NEAR 5 KFT. ALTHOUGH THERE ARE STILL SOME ISOLATED SHOWERS ACROSS THE SOUTHERN PORTIONS OF THE PEE DEE AS OF 06Z...WE WILL BE HARD PRESSED TO SEE ANY SHOWERS DURING THE DAY IF THE CAP IN THE 3-5 KFT FT LAYER HOLDS AS EXPECTED. WINDS WILL BE LIGHT TODAY...BUT GIVEN THE MOVEMENT OF SURFACE HIGH PRESSURE... WINDS WILL VEER AROUND TO S AND SE THIS AFTERNOON AND SW AND S TONIGHT. ONSHORE FLOW WILL KEEP THE BEACHES COOLEST TODAY...AND CLOUD COVER SHOULD ALSO ACT TO CAP MAXIMUMS THROUGHOUT. WE EXPECT MID AND UPPER 70S NEAR AND AT THE COAST TO LOWER 80S WELL INLAND. TONIGHT...A WEAK SHORTWAVE TROUGH EMBEDDED IN WNW FLOW MAY APPROACH THE EASTERN CAROLINAS LATE. MODELS ARE SHOWING A SUBTLE INCREASE IN OMEGA FIELDS AND PRECIPITABLE WATER VALUES...ALREADY RATHER HIGH... DO INCREASE FURTHER...TO NEAR 1.5 INCHES. SURFACE INSTABILITY WILL BE VIRTUALLY NONEXISTENCE...BUT ELEVATED CAPE VALUES DO INCREASE. WILL SHOW AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FROM W TO E TONIGHT...ESPECIALLY LATE AT NIGHT. CLOUDS AND SOUTHERLY FLOW SHOULD KEEP TEMPS ELEVATED OVERNIGHT. WILL SHOW COOLEST READINGS CAPE FEAR WHERE SOUTHERLY FLOW WILL BE WEAKEST LONGEST. MODEL PROFILES SHOW LOW LEVEL JET STRENGTHENING TO 25 KT NEAR 1500 FT ACROSS OUR WESTERN ZONES BY DAYBREAK FRI. GIVEN THE RECENT FIRES IN AND NEAR THE AREA...THE AIR WILL CONTINUE TO SMELL SMOKEY AND AN AIR QUALITY ALERT WILL REMAIN IN EFFECT FOR SOUTHEAST NORTH CAROLINA TIL 3 PM. THE NORTH CAROLINA DEPARTMENT OF ENVIRONMENTAL AND NATURAL RESOURCES HAS ISSUED A CODE ORANGE AIR QUALITY ACTION DAY FOR FINE PARTICULATES. AN INCREASING SOUTHERLY FLOW MAY HELP TO REDUCE THE SMOKINESS ACROSS THE AREA LATER TODAY AND TONIGHT...BUT A WIDESPREAD SOAKING RAIN IS WHAT IS SORELY NEEDED TO PUT OUT THE SMOLDERING FIRES. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 AM THURSDAY...UPPER PATTERN CHANGES FRI WITH DEEP NORTHWEST FLOW AT THE START OF THE PERIOD BECOMING DEEP SOUTHWEST FLOW BY FRI EVENING AS WEAK UPPER RIDGE AXIS SHIFTS SOUTHEAST. SURFACE AND UPPER TROF MOVE INTO THE AREA FRI NIGHT INTO SAT...ACCOMPANIED BY DEEP MOISTURE. FORECAST SOUNDINGS FRI AND SAT SUGGEST A GOOD SHOT AT PRECIP BOTH DAYS. LIMITING FACTOR ON FRI MAY END UP BEING SURFACE HEATING. TEMPS...ESPECIALLY ACROSS NC...MAY FALL SHORT OF BEING WARM ENOUGH TO FIRE CONVECTION. THERE ALSO DOES NOT APPEAR TO BE MUCH UPPER LEVEL SUPPORT FRI AFTERNOON. DO THINK SOME STORMS WILL DEVELOP...BUT COVERAGE WILL LIKELY BE IN THE LOW CHC CATEGORY AT BEST. SAT AND SAT NIGHT APPEAR MORE PROMISING PRECIP WISE. DEEP SOUTHWEST FLOW WILL NOT ONLY ADVECT MOISTURE INTO THE AREA...BUT WILL PUSH HIGHS INTO THE LOWER 80S. ANTICIPATE AN INCREASE IN STORM COVERAGE SAT...THOUGH KEEPING POPS IN THE CHC RANGE FOR NOW. ALTHOUGH ATMOSPHERE WILL BE SLIGHTLY MORE UNSTABLE SAT...THERE IS STILL NO SIGNIFICANT SURFACE OR UPPER LEVEL FEATURE WORKING TO ENHANCE CONVECTION. INSTABILITY INCREASES SAT NIGHT AS HEIGHTS CONTINUE TO FALL WITH APPROACH OF CUTOFF LOW. LATE IN THE PERIOD FRONT WILL APPROACH FROM THE WEST PRECEDED BY NOCTURNAL JET AND DIFFLUENT FLOW ALOFT...WHICH SHOULD HELP KEEP STORMS GOING ALONG THE BOUNDARY. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 3 AM THURSDAY...LOW CONFIDENCE FORECAST WITH UNSETTLED PATTERN IN PLACE THROUGH THE PERIOD. AREA REMAINS UNDER INFLUENCE OF SURFACE AND UPPER TROF WITH NORTH-SOUTH STATIONARY FRONT THROUGH THE CAROLINAS. BEST PRECIP CHANCES ARE GOING TO OCCUR WHENEVER WEAK SHORTWAVES MOVE ACROSS THE AREA. AS THESE CANNOT REALISTICALLY BE PINNED DOWN THIS FAR OUT WILL CONTINUE WITH BLANKET CHC POPS. CLOUD COVER AND LOW LEVEL MOISTURE WILL KEEP HIGHS JUST SHORT OF CLIMO WHILE HELPING LOWS STAY A LITTLE ABOVE CLIMO. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... AS OF 06Z...HIGH CONFIDENCE OF VFR THROUGH THE END OF THE FORECAST...WITH LOW CONFIDENCE OF POSSIBLE MVFR FOG DEVELOPMENT IN THE PRE-DAWN HOURS. ISOLATED TSRA ACTIVITY DEVELOPED LAST EVENING AND HAS NOW CLEARED THE FLO TERMINAL. DO NOT EXPECT ANY OTHER SHRA/TSRA ACTIVITY TO AFFECT ANY OF THE TERMINALS OVERNIGHT. WINDS WILL GENERALLY BE E... SHIFTING MORE SE DURING THE AFTERNOON...UP TO 8-10 KTS. HAVE CONTINUED TO NOT INCLUDE FOG AT ANY TERMINALS IN FORECAST DUE TO FORECASTED CLOUD COVER. HOWEVER...WITH RESIDUAL MOISTURE FROM PREVIOUS SHRA ACTIVITY AND LIGHT WINDS...IF CLOUDS HAPPEN TO CLEAR OUT MORE THAN EXPECTED...POSSIBLE MVFR FOG COULD DEVELOP. WILL UPDATE AS NEEDED IN LATER TAF ISSUANCES. EXTENDED OUTLOOK...SCATTERED AFTERNOON AND EVENING CONVECTION POSSIBLE EACH DAY THROUGH SATURDAY. MORE WIDESPREAD SHOWERS ARE POSSIBLE SUNDAY AND MONDAY. LOCALIZED IFR POSSIBLE EACH MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM THURSDAY...SURFACE HIGH PRESSURE TO OUR N...WILL SHIFT S AND THEN E THROUGH THE PERIOD. WINDS WILL BE FROM THE E AND NE FOR MOST OF THE DAY. WINDS WILL VEER TO SE THIS EVE AND TO S TONIGHT. INCREASING LOW LEVEL JET WILL REMAIN W OF THE WATERS THROUGH THE PERIOD. RELAXED PRESSURE GRADIENT WILL KEEP THE WINDS UNDER 15 KT. SEAS WILL BE COMPRISED PRIMARILY OF A 3 TO 4 FT...10 TO 11 SECOND EASTERLY SWELL. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 AM THURSDAY...ANTICIPATE SOUTHERLY FLOW THROUGH THE PERIOD WITH WINDS GAINING A LITTLE MORE WESTERLY COMPONENT LATE IN THE PERIOD. SPEEDS WILL START OUT AROUND 10 KT FRI...BUT INCREASE TO A SOLID 15 KT BY LATE SAT AS GRADIENT TIGHTENS. FRONT APPROACHES FROM THE WEST BUT WILL REMAIN WEST OF THE WATERS. SEAS IN THE 2 TO 4 FT RANGE AT THE START OF THE PERIOD WILL STEADILY BUILD TO 3 TO 5 FT SAT NIGHT. .LONG TERM /SUNDAY THROUGH MONDAY... AS OF 3 AM THURSDAY...SOUTH TO SOUTHWEST FLOW WILL CONTINUE OVER THE WATERS THROUGH THE PERIOD. THE ONLY EXCEPTION TO SOUTHWEST FLOW WOULD BE RELATED TO WEAK WAVES TRAVELING NORTHEAST ALONG FRONT STALLED OVER THE CAROLINAS. WIND SPEEDS WILL DEPEND ON THE LOCATION OF THE FRONT WITH RESPECT TO THE WATERS...BUT WOULD THINK 15 TO 20 KT WOULD BE WORST CASE SCENARIO. 3 TO 5 FT SEAS WILL CONTINUE THROUGH MONDAY...MAINLY SOUTHERLY SWELL. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$