AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 725 AM EDT MON JUN 27 2011 .SYNOPSIS... A SUMMERTIME AIR MASS WILL PREVAIL AS BERMUDA HIGH PRESSURE EXTENDS INTO THE AREA THROUGH TUESDAY. A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON TUESDAY INTO WEDNESDAY BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS. THIS FRONT SHOULD PUSH SOUTH OF THE AREA BY THURS AS HIGH PRESSURE BUILDS FROM THE NORTH AND HOLDS OVER THE AREA THROUGH MOST OF THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM MONDAY...MAINLY ISOLATED CONVECTION CONTINUES TO THE N...W AND S OF THE FORECAST AREA THIS MORNING. THIS ACTIVITY IS EXPECTED TO DIMINISH AROUND THE DAYBREAK HOUR. HOWEVER...LEFT OVER BOUNDARIES FROM THIS CONVECTION ALONG WITH THE SEA BREEZE BOUNDARY ARE EXPECTED TO BECOME AREAS OF INITIATION AS STRONG HEATING GETS UNDERWAY DURING THE MID AND LATE MORNING. IN ADDITION...A MID-LEVEL SHORTWAVE TROUGH WILL APPROACH THE AREA DURING THE AFTERNOON AND EVE. ALTHOUGH 700-500 MB LAPSE RATES WILL ONLY BE ON THE ORDER OF 6 DEG C/KM...CAPE VALUES ARE EXPECTED TO BE IN EXCESS OF 3000 J/KG WITH DOWNDRAFT CAPE VALUES NEAR 1000 J/KG. PRECIPITABLE WATER VALUES WILL BE GREATER THAN 1.75 INCHES. INVERTED-V SOUNDINGS WILL BE SUPPORTIVE OF STRONG GUSTY WINDS AT THE SURFACE. ALL IN ALL... POTENTIAL FOR SHOWERS AND THUNDERSTORMS APPEARS HIGHER TODAY THAN ON SUN AND CLUSTERS OF THUNDERSTORMS SHOULD BE ABLE TO ORGANIZE WITH NEW ACTIVITY DEVELOPING ON THE OUTFLOW BOUNDARIES. THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE STRONG GUSTY WINDS AND FREQUENT LIGHTING. IN ADDITION...WITH STORM MOTIONS UNDER 10 KT... THUNDERSTORMS THAT TRAIN IN THE SAME GENERAL AREAS COULD PRODUCE LOCALIZED FLOODING. STRONG THUNDERSTORMS WILL HAVE THE POTENTIAL TO BRIEFLY PULSE TO SEVERE LEVELS. THE BEST CHANCE FOR THUNDERSTORMS WILL BE LATE MORNING AND THIS AFTERNOON. HOWEVER...WE WILL BE WATCHING FOR AN ORGANIZED THUNDERSTORM COMPLEX PERHAPS DEVELOPING OR MOVING INTO THE LEE OF THE APPALACHIANS THIS AFTERNOON AND THEN MOVING ACROSS THE FORECAST AREA LATE DAY AND TONIGHT. ACTIVITY ACROSS THE EASTERN CAROLINAS MAY LAST INTO THE LATE NIGHT HOURS. HEAT INDICES WILL LIKELY TOP 100 DEGREES THIS AFTERNOON IN MOST PLACES...BUT REMAIN BELOW ADVISORY CRITERIA AS TEMPS REACH THE LOWER TO MID 90S. THE BEACHES AND ADJACENT AREAS WILL NOT QUITE REACH THE 90 DEGREE MARK DUE TO SEABREEZE INFLUENCES. ANOTHER WARM AND MUGGY NIGHT IS EXPECTED. VISIBILITIES IN THE VICINITY OF THE HOLLY SHELTER FIRE WILL BE LESS THAN A QUARTER OF A MILE UNTIL LATE MORNING. A DENSE SMOKE ADVISORY WILL REMAIN POSTED FOR PENDER COUNTY UNTIL THE LOW LEVEL INVERSION BREAKS. NO SIGNIFICANT VISIBILITY RESTRICTIONS DUE TO SMOKE ARE EXPECTED BY THIS AFTERNOON. THE POTENTIAL FOR SIGNIFICANT RAINFALL IN THE FIRE ZONES IS POSSIBLE THIS PERIOD. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...SOUTHERLY WINDS WILL INCREASE AHEAD OF AN APPROACHING COLD FRONT ON TUESDAY. COLD FRONT SHOULD REACH THE MOUNTAINS BY AFTERNOON WITH A MOIST UNSTABLE AIR MASS AHEAD OF IT . EXPECT INITIAL CONVECTIVE DEVELOPMENT WITH BEST CONVERGENCE ALONG SEA BREEZE BOUNDARY LOCALLY. ANY SHWRS/TSTMS SHOULD REMAIN WEST OF CWA UNTIL LATE DAY TUES WHEN FRONT PUSHES EAST AND SHORTWAVE MOVES THROUGH AREA. THIS SHORTWAVE WILL MOVE THROUGH TUES NIGHT INTO WED MORNING WHICH WILL HELP TO PRODUCE MORE WIDESPREAD SHWRS/TSTMS ACROSS AREA. PCP WATER VALUES REACH OVER 2 INCHES AND FOLLOWING THE AXIS OF GREATEST VALUES....WOULD EXPECT ACTIVITY TO MOVE THROUGH WESTERN PORTION OF CWA TUES EVENING REACHING THE COAST AROUND MIDNIGHT AND OFF SHORE BY WED MORNING. AS SHORTWAVE MOVES OFF SHORE WINDS ALOFT VEER AROUND TO THE W-NW WHILE SURFACE BOUNDARY GETS HUNG UP TO THE WEST. SEA BREEZE WILL HELP TO MASK PROGRESSION OF FRONTAL BOUNDARY. AS SEA BREEZE DEVELOPS WED...SHOULD SEE ANOTHER ROUND OF CONVECTION ASSOCIATED WITH SFC FRONT AND SEA BREEZE BOUNDARY. BY WED NIGHT INTO THURS DEEP LAYER NW FLOW WILL BRING DRIER AIR IN THROUGHOUT THE LOW TO MID LEVELS AS COLD FRONT PROGRESSES TOWARD THE COAST. PCP WATER VALUES DROP TO DOWN TO 1.5 INCHES OR LESS BY END OF THURS MORNING. MAX TEMPS WILL REMAIN WITHIN A COUPLE OF DEGREES OF CLIMO...AROUND 90...BUT OVERNIGHT LOWS WILL REMAIN ABOVE NORMAL IN A MOIST SUMMER TIME AIR MASS. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3 AM MONDAY...HIGH PRESSURE WILL BUILD IN BEHIND COLD FRONT ON THURS. DRIER AIR WILL MOVE IN THROUGH THE LOW TO MID LEVELS OF THE ATMOSPHERE IN A DEEPER LAYER NW-N FLOW AS SHORTWAVE EXITS THE COAST. COLD FRONT MAKES A RUN FOR THE COAST EARLY THURS AS WINDS VEER AROUND TO THE NORTH. GFS SHOWING PCP WATER VALUES DOWN LESS THAN AN INCH BY THURS AFTN. MAY SEE SOME RESIDUAL MOISTURE FROM PREVIOUS CONVECTION HELPING TO PRODUCE CU ON THURS AND WILL LEAVE VERY LOW END CHC OF SHWRS FOR THURS. OVERALL WILL SEE A DRIER AIR MASS IN PLACE THROUGH MOST OF THE EXTENDED. WINDS WILL CONTINUE TO VEER AROUND TO THE E-SE AND EVENTUALLY SOUTH BY SAT BUT SHOULD SEE A FEW DRY DAYS WITH MORE IN THE WAY OF ISOLATED CONVECTION AT BEST. MAY NOT SEE MUCH IN THE WAY OF SHWR ACTIVITY FROM THURS THROUGH SAT WITH A SLIGHTLY BETTER CHC BY THE END OF THE WEEKEND AS MID TO UPPER RIDGE BUILDS IN FROM THE WEST WHICH SHOULD HOLD ALL SHORTWAVES TO THE NORTH AND PUT A LID ON CONVECTION THROUGH MUCH OF THE PERIOD. H5 HEIGHTS WILL BE ON THE INCREASE AS WELL AS 850 TEMPS. GFS SHOWING 850 TEMPS DOWN TO 15 C BY THURS AFTN BUT THEY REBOUND RAPIDLY UP TO 21 C BY LATE SAT AS RIDGE BUILDS IN ALOFT. THEREFORE EXPECT TEMPS TO START OUT AT OR BELOW CLIMO ON THURS BUT REACHING INTO THE 90S THROUGH MOST OF THE PERIOD. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 12Z...MAIN FORECAST CONCERN WILL BE POTENTIAL CONVECTION THIS AFTERNOON. WITH MODELS SHOWING GOOD INSTABILITY...REMNANT BOUNDARIES FROM PREVIOUS CONVECTION AND DEVELOPING SEA BREEZE COULD TRIGGER STORM ACTIVITY. ANY STORMS THAT DEVELOP WILL CAUSE STRONG AND GUSTY WINDS ALONG WITH BRIEF PERIODS OF LOWERED VSBYS...POSSIBLE IFR...WITHIN HEAVIEST RAINFALL. KEEPING VCSH/VCTS FOR NOW AS TIMING AND COVERAGE IS HARD TO DETERMINE ATTM. SEA BREEZE WILL ONCE AGAIN DEVELOP AND PUSH INLAND...ALLOWING FOR SOUTHERLY FLOW AROUND 10-15 KTS THROUGHOUT THE DAY. OVERNIGHT...CURRENT MODEL SOUNDINGS SHOW SIGNS OF A POSSIBLE STRATUS LAYER AT THE COASTAL TERMINALS. HOWEVER...NOCTURNAL LLJ COULD KEEP VFR TO RULE. WILL LEAVE OUT MENTION IN TAFS AND UPDATE WITH LATER ISSUANCES. EXTENDED OUTLOOK...ISOLATED SHOWERS/THUNDERSTORMS POSSIBLE EACH AFTERNOON THROUGH THURSDAY. VFR FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM MONDAY...SW WINDS WILL BE ENHANCED BY THE SEABREEZE BOUNDARY THIS AFTERNOON AND THROUGH THE EVE. ALTHOUGH THERE IS LITTLE EVIDENCE OF A NOCTURNAL JET TONIGHT...SHOULD AN ORGANIZED AREA OF CONVECTION APPROACH THE WATERS...WINDS COULD REMAIN ELEVATED WELL INTO THE NIGHT. A WEAK SE SWELL WILL EXIST...BUT THE WAVE SPECTRUM WILL BE DOMINATED BY SW WIND WAVES THROUGH THE PERIOD. SEAS WILL BE IN THE 3 TO 4 FT RANGE THIS PERIOD WITH 5 FOOTERS POSSIBLE ACROSS THE OUTER WATERS TONIGHT. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...GRADIENT WILL TIGHTEN ON TUES BETWEEN BERMUDA HIGH AND APPROACHING COLD FRONT. INCREASING SW WINDS UP AROUND 20 KTS ON TUES WILL DRIVE THE SEAS UP TOWARD SCA THRESHOLDS. EXPECT SEAS IN THE 4 TO 5 FT RANGE MOST WATERS WITH SOME 6 FTERS IN OUTER WATERS. SEAS SHOULD PEAK WED MORNING BEFORE DECREASING IN A MORE OFF SHORE FLOW AS WINDS VEER AROUND BEHIND COLD FRONT BY WED NIGHT INTO EARLY THURS. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM MONDAY...WINDS WILL VEER AROUND FROM THE NORTH TO NE AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH THURS INTO FRI. BY END OF PERIOD WINDS WILL COME BACK AROUND TO THE S-SW AS BERMUDA HIGH PRESSURE TAKES CONTROL ONCE AGAIN. GRADIENT FLOW WILL BASICALLY REMAIN 15 KTS OR LESS WITH GREATEST WINDS IN SEA BREEZE EACH AFTN NEAR SHORE. SEAS WILL REMAIN 3 FT OR LESS THROUGH MOST OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...DENSE SMOKE ADVISORY UNTIL 11 AM EDT THIS MORNING FOR NCZ105- 106. MARINE...NONE. && $$