Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 030912 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 512 AM EDT MON AUG 3 2015 .SYNOPSIS... LOW PRESSURE WILL MOVE ALONG A STATIONARY BOUNDARY DRAPED ALONG THE COAST THROUGH TUESDAY...BRINGING SHOWERS AND THUNDERSTORMS TO MUCH OF THE AREA. THIS LOW PRESSURE WILL MOVE AWAY TUESDAY NIGHT...FOLLOWED BY BERMUDA HIGH PRESSURE CREATING TYPICAL SUMMERTIME WEATHER THROUGH THE REMAINDER OF THE WEEK. A COLD FRONT WILL CROSS ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM MONDAY...LATEST MSAS INDICATES THE SFC BOUNDARY REMAINS STALLED JUST INLAND FROM THE COAST. THE FA REMAINS REMAINS SOMEWHAT SANDWICHED BETWEEN ATLANTIC MARINE TROPICAL AIRMASS AND A CONTINENTAL DRY AIRMASS RELATIVELY SPEAKING. A STREAM OF LOW TO MID LEVEL MOISTURE FROM THE TROPICS EXTENDS OVERHEAD JUST EAST AND SOUTH OF THE STATIONARY FRONT THAT LIES JUST INLAND FROM THE COAST. AT THE MOMENT A WEAK SFC LOW IS EXITING TO THE NE OF THE FA TAKING WITH IT THE MAJORITY OF THIS MORNINGS PCPN. AS THE DAY PROGRESSES...THE S/W TROF ALOFT AND ASSOCIATED SFC LOW WILL TRACK NE ACROSS NORTHERN FL AND INTO SOUTHERN GA LATER THIS EVENING...AND SOUTHERN SC BY DAYBREAK TUE. DYNAMICS FROM THESE FEATURES WILL INTERACT WITH THE STREAM OF MOISTURE EXHIBITING PWS GREATER THAN 2 INCHES...AND PRODUCE MAINLY HEAVY RAIN PRODUCING SHOWERS AND THUNDERSTORMS. BEST PCPN COVERAGE AND HIEST POPS THRU TONIGHT WILL REMAIN CONCENTRATED ALONG THE IMMEDIATE COAST. WILL EXHIBIT A RATHER SHARP DECREASING TREND TO THE POPS AS 1 MOVES INLAND FROM THE COAST. BY THE TIME 1 REACHES THE I-95 CORRIDOR... POPS WILL GENERALLY BE ISOLATED TO LOW CHANCE CATEGORY. AS FOR TEMPS...CUT A FEW DEGREES OFF TODAYS MAX TEMPS FROM THE PREVIOUS UPDATE. THIS DUE TO ONGOING PCPN AND MORE WIDESPREAD AND OPAQUE CLOUDINESS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...BIG CHANGES IN THE GUIDANCE FROM LAST NIGHT...BUT FORTUNATELY HAVE BEEN HANDLED WELL BY THE AFTN FORECASTER. LOW PRESSURE MOVING ALONG A STALLED BOUNDARY WILL BE PUSHING SLOWLY NE JUST OFF THE COAST TUESDAY MORNING. NHC GIVES THIS A 10% CHANCE OF DEVELOPING INTO A TROPICAL SYSTEM...AND GUIDANCE IS DEVELOPING A WEAK ASYMMETRIC WARM CORE...BUT IT PROBABLY WILL NOT HAVE ENOUGH TIME TO BECOME ANYTHING TRULY TROPICAL. REGARDLESS...VERY MOIST AIRMASS NOTED BY PWATS OVER 2.25 INCHES ALONG THE COAST WILL SUPPORT PERIODS OF HEAVY RAINFALL THE FIRST HALF OF TUESDAY BEFORE THIS LOW SKIRTS OFF TO THE NE. SREF PROBS ARE WELL OVER 80% FOR THE COASTAL COUNTIES...BUT TOWARDS I-95...AREAS THAT TRULY NEED THE RAIN...WILL SEE MUCH LIGHTER AMOUNTS THANKS TO A MUCH DRIER AIRMASS. WILL BUMP POP TO LIKELY TUESDAY MORNING BEFORE SLOWLY WINDING DOWN TUESDAY NIGHT. BY WEDNESDAY...LOW PRESSURE WILL BE WELL AWAY FROM THE AREA WITH RIDGING DEVELOPING ALOFT. THIS WILL LEAD TO MORE TYPICAL SUMMERTIME CONVECTION CHANCES...ALTHOUGH WILL MAINTAIN SUB-CLIMO POP DUE TO SUBSIDENCE ALOFT AND A DRIER COLUMN. TEMPS TUESDAY WILL FEATURE A WIDE RANGE ACROSS THE CWA. TEMPS ALONG THE IMMEDIATE COAST...ESPECIALLY THE CAPE FEAR COAST...MAY STRUGGLE OUT OF THE MID 80S THANKS TO CLOUDS AND RAIN...WHILE LOCATIONS WEST OF I-95 WILL AGAIN SOAR ABOVE 95 DEGREES. WEDNESDAY WILL BE MORE UNIFORM AND HOTTER...WITH HIGHS REACHING WELL INTO THE 90S EVERYWHERE...AND MAYBE A SPOT 100 IN THE WARMEST PLACES. LOWS BOTH NIGHTS WILL BE A DEGREE OR 2 EITHER SIDE OF 75. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...HOT WEATHER THURSDAY AS RIDGING ALOFT PERSISTS ONE MORE DAY WILL TRANSITION QUICKLY ON FRIDAY AS A COLD FRONT CROSSES THE AREA. THIS FRONT LOOKS SURPRISINGLY STRONG FOR EARLY- AUGUST...AND IN ADDITION TO GOOD CONVECTION CHANCES FRIDAY AND SATURDAY...MUCH COOLER TEMPERATURES WILL FOLLOW IN ITS WAKE. THE SUBSEQUENT LONGWAVE TROUGH IS FORECAST TO BE -1 TO -2 SD`S FROM CLIMO...AND BOTH MEX/ECE NUMBERS ARE ALREADY BELOW CLIMO EVEN AS THEY ARE POSITIVELY INFLUENCED BY THE MEAN. THIS SUGGESTS THAT THURSDAY WILL BE HOT...FRIDAY SEASONABLE...AND THEN BELOW NORMAL FOR THE WKND. INHERITED LOOKS GOOD FOR THE WKND WITH MID-TO-UPR 80S AND WILL DROP ONLY SLIGHTLY. BY SUNDAY HOWEVER...DRIER AIR IS FORECAST SO POP WILL RAMP DOWN BEHIND THE BOUNDARY. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... AS OF 06Z...SURGE OF PRECIPITATION MOVING UP AND ALONG THE SE U.S. COAST. FORECAST ISSUE OF THE DAY WILL BE THE SURFACE LOW ACROSS THE NE GULF OF MEXICO MOVING/DRIFTING NE INTO NRN FLORIDA...AND THEN INTO GEORGIA WITHIN THE NEXT 24 HOURS. PWAT AMOUNTS INCREASE TO ABOUT 2.25 INCHES ACROSS MAINLY THE COASTAL AREAS AS PER THE MODEL SOUNDINGS BUT REMAINING LESS THAN 2 INCHES INLAND. MODELS SHOW SHARP DECREASE IN THE PRECIPITATION SHIELD AS YOU MOVE WESTWARD...WITH INTERSTATE 95 ACTING LIKE THE DIVIDING LINE BETWEEN PCPN OR NO PCPN. ANY SHIFT IN THE MODELS JUST 30 MILES EITHER WAY CAN HAVE A SIGNIFICANT IMPACT ON THE FORECAST. WILL MAINLY HEDGE WITH MVFR PERHAPS IFR ALONG THE COASTAL TERMINALS DURING THE DAY WITH PERIODS OF RAIN SOME OF WHICH MIGHT BE HEAVY AND VFR/MVFR INLAND WITH SOME SHWRS. MOST OF THE ACTIVITY WILL BE ALONG THE COAST. CONFIDENCE IN FORECAST CONDITIONS ARE LOW AS MODELS DIFFER WITH SPEED AND STRENGTH OF LOW COMING OUT OF THE GOM. EXTENDED OUTLOOK...PREDOMINANTLY VFR THROUGH THE PERIOD WITH A SLIGHT CHANCE AFTERNOON SHRA/TSRA. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM MONDAY...HOISTED A TEMPORARY SCA FOR THE ILM NC WATERS TODAY AND A SCEC FOR THE ILM SC WATERS...THRU 6 PM. ACTIVE SOUTHERLY WINDS OVERNIGHT PUSHED SIGNIFICANT SEAS TO 4 TO 7 FT ACROSS THE AREA WATERS NORTH OF LITTLE RIVER INLET TO SURF CITY...MAINLY CONCENTRATED IN THE VICINITY OF CAPE FEAR PER LATEST BUOY READINGS FROM 41013 AND 41108. THIS WILL BE TEMPORARY AS THE S/W TROF ALOFT PUSHES NE OF THE AREA WATERS THIS MORNING ALLOWING THE SFC PG TO RELAX-SOME. WOULD NOT BE SURPRISED TO SEE THIS SCA DOWNGRADED BY NOON. HOWEVER...INSTEAD OF PLAYING THE YO-YO GAME...MAY ACTUALLY WANT TO KEEP BOTH HOISTED IN ANTICIPATION OF THE NEXT OR MAIN SFC LOW AND ASSOCIATED DYNAMICS ALOFT...APPROACH THE FA FROM THE SW. THIS WILL LIKELY RE-TIGHTEN THE SFC PG YIELDING 15 KT TO 25 KT SUSTAINED WIND SPEEDS AND PRODUCE A SFC PRESSURE PATTERN YIELDING MAINLY SSE-SW WIND DIRECTIONS. HEALTHY SIGNIFICANT SEAS WILL BE COMPRISED MAINLY OF A SOUTHERLY WIND WAVE AT 6 TO 7 SECOND PERIODS...AND A 1 TO 2 FOOT SE-SSE 10-11 SECOND PERIOD GROUND SWELL. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...POSSIBLE SCA CONDITIONS START THE PERIOD AS A LOW PRESSURE WILL BE SLOWLY MOVING ALONG A STATIONARY BOUNDARY DRAPED ALONG THE COAST. ALTHOUGH SOUTHERLY WINDS ARE FORECAST TO REMAIN JUST BELOW SCA THRESHOLDS...UP TO 20 KTS...THE PROLONGED DURATION AND FETCH OF THESE WINDS WILL DRIVE SEAS UP TO 4-6 FT INTO TUESDAY NIGHT. AS THE LOW PULLS AWAY TUESDAY NIGHT WINDS WILL EASE AND SHIFT TO THE W/NW FOR A SHORT TIME INTO WEDNESDAY MORNING...BEFORE BERMUDA HIGH PRESSURE BUILDS BACK TOWARDS THE WATERS AND WINDS RETURN TO THE S/SW AT 10-15 KTS LATE WEDNESDAY. SEAS WILL BE HIGHEST FIRST THING WEDNESDAY AT 3-5 FT THANKS TO THE RESIDUAL SPECTRUM FROM TUESDAY...BEFORE FALLING TO 2-4 FT AT THE END OF THE PERIOD. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...BERMUDA HIGH PRESSURE WILL DOMINATE THE FLOW THURSDAY AND MOST OF FRIDAY...WITH TYPICAL SUMMERTIME 10-15 KT SW WINDS EXPECTED ACROSS THE WATERS. BRIEF INCREASES UP TO 20 KTS ARE POSSIBLE IN THE EVENING AS THE PIEDMONT TROUGH SHARPENS AS WELL. A COLD FRONT WILL APPROACH AT THE END OF THE PERIOD...BUT ANY WIND SHIFT WILL LIKELY HOLD OFF UNTIL BEYOND THE EXTENDED. SEAS WILL BE 2- 4 FT...RISING UP TO 3-5 FT THURSDAY EVENING ON THE SLIGHTLY INCREASED WINDS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR AMZ250- 252. && $$ SYNOPSIS...JDW NEAR TERM...DCH SHORT TERM...JDW LONG TERM...JDW AVIATION...DCH/MAC

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