Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 021154 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 754 AM EDT SUN AUG 2 2015 .SYNOPSIS... STATIONARY FRONT WILL REMAIN ACROSS THE AREA TODAY PRODUCING ISOLATED SHOWERS AND THUNDERSTORMS NEAR THE COAST. A WEAK WAVE OF LOW PRESSURE WILL MOVE ALONG THIS FRONT LATE TONIGHT AND ON MONDAY...BRINGING SLIGHTLY BETTER RAIN CHANCES TO THE AREA. THIS FRONT WILL DISSIPATE ON MONDAY AS BERMUDA HIGH RIDGES BACK INTO THE AREA THROUGH LATE WEEK. TEMPERATURES WILL REMAIN SEASONABLE TO SLIGHTLY ABOVE NORMAL THROUGH THE WEEK. A COLD FRONT WILL APPROACH NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM SUNDAY...PATCHY FOG WAS AROUND...OTHERWISE IT WAS A CLEAR TO PARTLY CLOUDY SUNRISE. TODAY IS EXPECTED TO BE SIMILAR TO SAT IN MANY RESPECTS. A WEAK FRONT/LAND BREEZE WILL BE OFFSHORE EARLY THIS MORNING AND THEN WITH STRONG HEATING...A DEVELOPING SEABREEZE WILL PUSH INLAND. THE FORECAST AREA ON THE WHOLE WILL BE DRIER TODAY THAN ON SAT. PRECIPITABLE WATER VALUES WILL BE AN INCH AND A HALF OR LESS THROUGHOUT DURING THE TIME OF PEAK HEATING. MODEL SOUNDINGS ARE ALSO SHOWING A CAP OF WARMER TEMPS ALOFT AT AROUND 12 KFT. THESE CONDITIONS SHOULD KEEP ANY CONVECTION ISOLATED...EVEN ALONG THE SEABREEZE. WILL CARRY SLIGHT CHANCE/SMALL CHANCE ALONG THE SEABREEZE AS IT MOVES INLAND...MAINLY THIS AFTERNOON AND EVE. WILL KEEP A DRY FORECAST ALONG THE INTERSTATE 95 CORRIDOR AND POINTS WEST. SINCE FORECAST HIGHS OVER THE LAST COUPLE OF DAYS HAVE BEEN TOO LOW...WILL GO AGAINST THE GRAIN...DESPITE THE UPPER TROUGH AND LOWERING HEIGHTS. WILL FORECAST MAINLY MID 90S...ALTHOUGH A FEW SPOTS WELL INLAND MAY AGAIN REACH THE UPPER 90S. ALONG THE COAST... LOWER 90S WILL BE MOST COMMON ALTHOUGH THE BEACHES MAY BY STYMIED IN THE UPPER 80S GIVEN THE DEVELOPING ONSHORE FLOW. TONIGHT...THE FORECAST BECOMES MORE COMPLICATED. THE NAM MODEL IS FORECASTING A CLOSED CIRCULATION DEVELOPING ALONG A WEAK BOUNDARY. THE NAM DEVELOPS THE LOW TO OUR S AND CARRIES IT N ALONG THE COAST OF NORTHEAST SOUTH CAROLINA AND SOUTHEAST NORTH CAROLINA DURING THE PRE-DAWN HOURS OF MON AND MON MORNING. THE LOW THEN LIFTS N OF CAPE LOOKOUT MON AFTERNOON. THIS RECENT DEVELOPMENT DOES NOT SEEM A LIKELY SCENARIO. THE GFS SHOWS MORE OF AN INVERTED TROUGH POKING UP THE COAST. HOWEVER...THESE SOLUTIONS GIVE A SIMILAR FORECAST AS IT RELATES TO SENSIBLE WEATHER WITH PRECIPITABLE WATER VALUES RAMPING HIGHER VERY LATE TONIGHT ALONG THE COAST. THUS WILL SHOW POPS INCREASING DURING THE OVERNIGHT HOURS AND INTO MON MORNING. AS IS OFTEN THE CASE...THE MODELS DO SEEM TO BE TOO FAR WEST WITH THEIR DEVELOPING PRECIPITATION SHIELD...ALTHOUGH I DO AGREE THERE WILL BE A RATHER SHARP POP GRADIENT. WILL CONFINE LIKELY POPS TO THE WATERS...TRENDING TO GOOD CHANCE/CHANCE ALONG THE COAST WITH SMALL POPS DECREASING BELOW THRESHOLD AS YOU MOVE TO THE I-95 CORRIDOR. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 AM SUNDAY...PERSISTENT STATIONARY FRONT WILL FINALLY DISSIPATE OVERHEAD MONDAY THANKS TO RIDGING SLOWLY BULGING OUT OF THE ARKLATEX REGION. THIS LEADS TO A MORE TYPICAL MID-LEVEL PATTERN FOR AUGUST WITH VERY WEAK BAROCLINIC GRADIENTS...ERODING THE BOUNDARY COMPLETELY. BEFORE THIS OCCURS THOUGH...ENOUGH FORCING WILL PERSIST ALONG THE FRONT AND AN AFTN SEA BREEZE BOUNDARY TO PRODUCE ISOLATED/SCT SHOWERS AND TSTMS MONDAY. THE BEST CHANCE WILL BE ACROSS THE EASTERN THIRD OF THE CWA WHERE PWATS WILL BE MUCH HIGHER SE OF THE FRONT...AND WHERE THE SEA BREEZE WILL LIKELY AID IN CONVECTIVE DEVELOPMENT. ADDITIONALLY...GUIDANCE IS INDICATING A WAVE OF LOW PRESSURE DEVELOPING ALONG THIS BOUNDARY AND ENHANCING PRECIP ALONG THE CAPE FEAR COAST. WHILE THE NAM APPEARS TOO STRONG WITH THIS FEATURE...HAVE SEEN A FEW WAVES ALONG THIS FRONT OVER THE PAST FEW DAYS...AND THUS THERE IS SOME CONFIDENCE IN ONE MORE THIS PERIOD. HAVE BUMPED POP TO LOW-LIKELY FROM ABOUT HOLDEN BEACH TO CAROLINA BEACH AND SE...WITH HIGH CHC JUST INLAND FROM THERE. THERE WILL BE A VERY SHARP GRADIENT HOWEVER...AND THE BEST CONVECTION MAY REMAIN LURKING JUST OFFSHORE. THE WESTERN HALF OF THE CWA SHOULD AGAIN BE TOO DRY AS A VERY SHARP MOISTURE GRADIENT EXISTS ACROSS THE AREA...AND WILL KEEP POP SILENT FOR THE I-95 COUNTIES. TEMPS ON MONDAY WILL BE SIMILAR TO WHAT WE HAVE SEEN THE PAST SEVERAL DAYS...ABOUT 90 AT THE COAST...RISING TO AROUND 97 IN THE WARMEST INLAND ZONES. MINS WILL REMAIN ABOVE CLIMO ACROSS THE AREA...72 WELL INLAND TO AS WARM AS 78 ON THE BEACHES. TUESDAY WILL BE THE NICER OF THE TWO DAYS...BUT ALSO HOTTER THANKS TO HEIGHTS BUILDING ALOFT AS THE RIDGE DISPLACES THE LONGWAVE TROUGH. 850MB TEMPS CLIMB TO AROUND 20C...AND PWATS DROP BELOW 1.5 INCHES BENEATH A STRENGTHENING SUBSIDENCE INVERSION. 6-HR SREF PROBS FOR 0.01 INCHES DEPICT A SMALL AREA OF 40-50% ALONG THE SEA BREEZE TUESDAY...BUT THIS IS WELL BELOW THE PERSONAL THRESHOLDS OF 80%+ FOR THIS PARAMETER FOR PRECIP. THIS COMBINED WITH VERY DRY AIR ABOVE THE INVERSION AND VERY WEAK INSTABILITY SHOULD PREVENT ANY SHOWER ACTIVITY...AND WILL KEEP POP SILENT ON TUESDAY. TEMPS WILL BE QUITE WARM TUESDAY...WITH SOME DOWNSLOPE FLOW DRIVING HIGHS INTO THE MID 90S ACROSS MUCH OF THE AREA...UPR 90S IN THE WARM SPOTS...WITH LOWS TUESDAY NIGHT FALLING ONLY INTO THE MID AND UPR 70S. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... AS OF 300 AM SUNDAY...HOT WEATHER ON TAP FOR MUCH OF THE EXTENDED AS LARGE UPPER RIDGE EXPANDS ACROSS THE SOUTHERN TIER AND INTO THE MID- ATLANTIC. THICKNESSES LOCALLY DO NOT GET EXCEEDINGLY ROBUST...BUT WILL BE ABOVE CLIMO...AND COMBINE WITH WARM 850MB TEMPS TO KEEP HIGHS AND LOWS LIKELY 3-6 DEGREES ABOVE CLIMO WED THU AND FRI. WED AND THU ALSO LOOK TO BE PRETTY DRY ACROSS THE AREA AS THE MID-LEVELS ARE DRY AND NO SIGNIFICANT FORCING IS EXPECTED. HOWEVER...WILL MAINTAIN INHERITED SCHC WED FOR TYPICAL SUMMERTIME ACTIVITY...AND DROP POP FROM INHERITED FOR THURSDAY FOR THE SAME REASONS. BY FRIDAY...A BOUNDARY WILL BEGIN TO APPROACH AND MOISTURE WILL INCREASE SO CONVECTION CHANCES WILL BEGIN TO RAMP UP...ESPECIALLY INTO SATURDAY AS THE FRONT CROSSES INTO THE AREA. WILL KEEP POP IN THE CHC RANGE FOR D6/D7 WITH COOLER TEMPS FOLLOWING THE FRONT NEXT WKND. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/...
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AS OF 12Z...PATCHY LIFR/IFR CIGS/VSBYS ARE OCCURRING SOUTH OF MYR/KFLO AND NE OF KLBT...BUT ALL TERMINALS ARE VFR. SHOWERS ARE WELL OFFSHORE EXCEPT SOME SPRINKLES ARE OCCURRING OUT OF MID CLOUDS NEAR THE COASTAL TERMINALS. A LAND BREEZE IS APPARENT ON DOPPLER RADAR MOVING OFFSHORE OF KILM. LIGHT NW-N WINDS WILL BECOME LIGHT N-NE THEN E THROUGH THE MORNING. SCT LOW CUMULUS WILL DEVELOP THIS MORNING AT THE COASTAL TERMINALS WITH SCT-BKN MID CLOUDS. AT KFLO/KLBT SCT MID CLOUDS EXPECTED. BY AFTERNOON WINDS WILL BECOME SE...AND ISOLATED SHOWERS WILL DEVELOP ALONG THE SEA BREEZE AS IT MOVES INLAND. THE CHANCE OF VCSH IS LOW AT THE TERMINALS...WITH EVEN LESS CHANCE OF VCTS. THIS EVENING WINDS BECOME LIGHT/VARIABLE AT KFLO/KLBT AND LIGHT SW AT THE COASTAL TERMINALS. OVERNIGHT VFR BECOMING MVFR DUE TO BR IN THE PRE-DAWN HOURS AT KFLO/KLBT. SHOWERS WILL BE INCREASING AT THE COASTAL TERMINALS IN THE PRE- DAWN HOURS WITH TEMPO MVFR POSSIBLE MAINLY KMYR/KCRE. EXTENDED OUTLOOK...CHANCE OF MVFR COASTAL TERMINALS MONDAY... OTHERWISE PREDOMINANTLY VFR THROUGH THE PERIOD WITH A SLIGHT CHANCE AFTERNOON SHRA/TSRA.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM SUNDAY...CONVECTION...WHILE WIDESPREAD...WAS ALL BEYOND 40 NM OF THE COAST. A WEAK FRONT WILL INTERACT WITH THE DAILY AFTERNOON SEA BREEZE AND EARLY MORNING LAND BREEZE. A TROUGH WILL EXPAND NORTH ALONG THE COAST TONIGHT. THE STRONGEST WINDS ARE AGAIN EXPECTED LATE IN THE AFTERNOON AND THROUGH THE EVE...UP TO AROUND 15 KT. MORNING WINDS WILL BE RATHER VARIABLE IN DIRECTION...BIASED TOWARD OFFSHORE GIVEN THE POSITION OF THE LAND BREEZE AND LIGHT. THE WIND DIRECTION THIS AFTERNOON AND TONIGHT WILL BE SOUTH. OVERNIGHT... THE WINDS ARE NOT EXPECTED TO DROP OFF SIGNIFICANTLY GIVEN THE EXPANDING TROUGH. SEAS WILL BE 3 TO 4 FT TODAY WITH SOME 5 FT SEAS DEVELOPING ACROSS PORTIONS OF THE OUTERMOST WATERS TONIGHT. SEAS WILL BE A FUNCTION OF BOTH WIND AND PERSISTENT SWELL. THERE WILL BE TWO DISTINCT SWELL COMPONENTS...ONE FROM THE S ON THE ORDER OF 7 SECONDS AND ONE FROM THE SE ON THE ORDER OF 10-11 SECONDS. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 AM SUNDAY...POSSIBLE SMALL CRAFT ADVISORY CONDITIONS DEVELOPING MONDAY AS A WAVE OF LOW PRESSURE MOVES ALONG A STATIONARY BOUNDARY WHICH WILL BE WAVERING ALONG THE COAST. AS THIS WAVE MOVES ALONG THE FRONT...THE GRADIENT WILL PINCH...CAUSING S/SW WINDS TO INCREASE ACROSS THE WATERS. HAVE EASED WINDS A BIT BELOW GUIDANCE SINCE THE WAVE SHOULD BE WEAK...BUT 15-20 KT WILL BECOME WIDESPREAD ON MONDAY. ALTHOUGH THIS IS JUST BELOW SCA THRESHOLDS...THESE WINDS WILL CREATE A WIND WAVE OF 5 FT AT 6 SEC...WHICH WILL COMBINE WITH A 2FT/11SEC SWELL TO PRODUCE 4-6 FT SEAS MUCH OF MONDAY. THE FRONT WILL DISSIPATE LATE MONDAY WITH A MUCH WEAKER GRADIENT LEFTOVER FOR TUESDAY. BERMUDA HIGH PRESSURE REBUILDING TOWARDS THE WATERS WILL MAINTAIN A SW WIND OF 10-15 KT...BUT SEAS WILL FALL TO 3-5 FT...HIGHEST EARLY IN THE DAY. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 300 AM SUNDAY...BERMUDA HIGH PRESSURE DOMINATES THE FLOW WED AND THU AS A NORMAL SUMMERTIME PATTERN DEVELOPS. WINDS AROUND THIS FEATURE WILL BE FROM THE TYPICAL SW DIRECTION...WITH SPEEDS OF 10-15 KT THROUGH MUCH OF THE PERIOD. THESE WINDS WILL DRIVE A WIND CHOP ATOP AN 11 SEC GROUND SWELL...AND SEAS WILL BE 3-4 FT...ISOLATED UP TO 5 FT AT TIMES...BOTH DAYS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JDW NEAR TERM...RJD SHORT TERM...JDW LONG TERM...JDW AVIATION...MRR MARINE...RJD/JDW

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