Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 281144 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 744 AM EDT THU MAY 28 2015 .SYNOPSIS... SEASONABLE WEATHER WILL LAST FOR THE NEXT SEVERAL DAYS AS HIGH PRESSURE WELL OFFSHORE REMAINS TOO WEAK TO IMPORT MUCH MOISTURE INTO THE SOUTHEASTERN U.S. A COLD FRONT MAY SAG INTO THE AREA NEXT TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM THURSDAY...A SLIGHT WESTWARD DRIFT OF THE UPPER LOW LOCATED WELL OFFSHORE AND EAST OF FLORIDA...WILL PUSH THE UPPER RIDGE AXIS...LOCATED JUST OFF THE CAROLINA COASTS...WESTWARD. ITS NEW POSITION WILL NEARLY BE OVERHEAD COME FRIDAY MORNING. A DEEPER LOW TO MID LEVEL ONSHORE FLOW WILL BECOME APPARENT BY TONIGHT AS WITNESSED BY THE LATEST AND VARIOUS MODEL SOUNDINGS FOR LOCATIONS ACROSS THE ILM CWA. EXPECT DIURNALLY DRIVEN GARDEN VARIETY CONVECTION TO DEVELOP AWAY FROM THE IMMEDIATE COAST BY MIDDAY...WHICH WILL PERSIST THROUGH SUNSET BEFORE QUICKLY DISSIPATING. THE MARINE INFLUENCES FROM A DEEPER ONSHORE FLOW ALONG THE IMMEDIATE COAST TODAY...WILL RESULT IN CONVECTIVE PARAMETERS NOT SUITABLE FOR THUNDERSTORM ACTIVITY TO DEVELOP. IE. PROGGED SOUNDINGS INDICATE CAPE WILL BE LESS THAN 1000 J/KG...WHEREAS INLAND LOOKING AT 2000-3000 J/KG. OVERALL...WILL INDICATE LOW CHANCE POPS INLAND. THE RESULTANT WIND BOUNDARY WILL DEVELOP BY MIDDAY AND PROGRESS INLAND THIS AFTN/EVE. IT COULD BECOME A FOCUS TO BRIEFLY AID THE DEVELOPMENT OF CONVECTION. BUT ONCE THIS BOUNDARY PASSES BY...ANY LEFTOVER CONVECTION BEHIND THIS BOUNDARY WILL LIKELY QUICKLY DISSIPATE. AS FOR THE MAX AND MIN FORECAST...WILL BE LOOKING AT A DEGREE OR 2 ON EITHER SIDE OF CLIMATOLOGY. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 AM THURSDAY... CONVECTION OUGHT TO BE PRETTY HARD TO COME BY ON FRIDAY SAVE FOR PERHAPS ISOLATED COVERAGE WELL INLAND. THIS IS MAINLY DUE TO SOME DRYING ALOFT AND A WEAK INVERSION DEVELOPING AROUND 700MB. INLAND HIGH TEMPS WILL BE A FEW DEGREES ABOVE CLIMO WHILE ONSHORE FLOW SHOULD TEMPER THINGS A BIT CLOSER TO THE COAST. WE DO SEE A RIBBON OF MID LEVEL MOISTURE THAT PEELS AWAY FROM THE UPPER LOW WELL OFFSHORE BUT ANY CONVECTION THAT RESULTS LIKELY ONLY AFFECTS THE WATER OVER THE GULF STREAM. THE AFOREMENTIONED INVERSION APPEARS TO MIX OUT IN FORECAST SOUNDINGS BY SATURDAY BUT THE DRY AIR APPEARS PRETTY STALWART. EXPECT A SIMILAR DAY TEMPERATURE-WISE AS WELL AS THE PROSPECTS AND FAVORED LOCATIONS FOR ANY SCANT CONVECTION. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 3 AM THURSDAY... PATTERN CHANGES TAKING SHAPE ON SUNDAY COMPARED TO THE RELATIVELY TRANQUIL SHORT TERM. LOW LEVEL MOISTURE WILL INCREASE SLIGHTLY BUT PERHAPS MORE IMPORTANTLY THE LIGHT MID LEVEL FLOW WILL BE TAKING ON A WEAK SOUTHWESTERLY COMPONENT AHEAD OF A SLOW MOVING SOUTHERN BRANCH TROUGH CROSSING THE MS VALLEY. WITH THESE FACTORS TAKING SHAPE SO GRADUALLY SUNDAY STILL LIKELY ONLY BRINGS SLIGHT CHANCE POPS OVER MAINLY WESTERN ZONES. PREVIOUS MODELS RUNS SUGGESTED THAT THE UPPER WAVE IN THE SOUTHERN BRANCH HELPED INCREASED MOISTURE THAT A BACKDOOR FRONT BEING PUSHED BY THE NORTHERN BRANCH MAY INTERACT WITH. AND WHILE THIS BOUNDARY SHOULD STILL SAG INTO THE AREA FOR SOME UNSETTLED WEATHER TUESDAY AND/OR WEDNESDAY IT APPEARS THAT IT WILL HAVE LITTLE HELP FROM THE SOUTHERN SYSTEM. RATHER, THIS FEATURE NOW APPEARS TO CUT OFF AND STALL. OF NOTE THIS TROUGH MAY BE INSTRUMENTAL BEYOND THE LONG TERM SETTING THE STAGE FOR HYBRID OR TROPICAL DEVELOPMENT IN THE EASTERN GOMEX...POSSIBLY AFFECTING THE REGION LATE NEXT WEEK. && .AVIATION /12Z THURSDAY THROUGH MONDAY/...
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AS OF 12Z...FOG AT KLBT/KFLO WILL DISSIPATE 12-1230Z. TEMPO MVFR CIGS ARE POSSIBLE EARLY THIS MORNING AT THE COASTAL TERMINALS AS THE SEA BREEZE DEVELOPS. LOW CLOUDS SHOULD SCATTER AT THE COASTAL TERMINALS MID-LATE MORNING AS THE SEA BREEZE MOVES INLAND AND WINDS BECOME SE 10 TO 15 KT. BKN LOW VFR CIGS WILL THEN DEVELOP AT THE KFLO/KLBT TERMINALS LATE MORNING/EARLY AFTERNOON AS SCATTERED SHRA AND ISOLATED TSRA BEGINS TO DEVELOP NEAR THESE TERMINALS. THE INLAND MOVING SEA BREEZE MAY ACT TO ENHANCE ACTIVITY IN THE AFTERNOON AT THE INLAND TERMINALS. NO CONVECTION EXPECTED AT THE COASTAL TERMINALS. AFTER SUNSET...CONVECTION WILL SLOWLY DISSIPATE AS WINDS SLOWLY DROP BACK TO LESS THAN 5 MPH. AFTER 08Z MVFR FOG POSSIBLE AGAIN AT KFLO/KLBT ESPECIALLY IF RAINFALL OCCURS. CONFIDENCE IS LOW HOWEVER. EXTENDED OUTLOOK...TYPICAL EARLY SUMMER PATTERN WITH MORNING FOG POSSIBLE EACH DAY AND MAINLY AFTERNOON ISOLATED/SCATTERED SHOWERS AND STORMS. OTHERWISE EXPECT VFR.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 600 AM THURSDAY...SFC RIDGING EXTENDING FROM THE HIGHS CENTER LOCATED OVER THE HIGH SEAS EAST OF THE MID-ATLANTIC STATES...WILL CONTINUE TO AFFECT THE AREA WATERS THIS PERIOD. THE ACTUAL SFC RIDGE AXIS LIFTS BACK TO THE NORTH THIS PERIOD...AND WILL EXTEND INLAND FROM THE ATLANTIC ACROSS NC. THIS POSITIONING WILL RESULT IN WINDS BACKING FROM SOUTHERLY TO ESE-SE. A SLIGHTLY RELAXED SFC PG WILL RESULT IN WIND SPEEDS AROUND 10 KT...OR 10-15 KT AT THEIR PEAK ESPECIALLY AT THE HEIGHT OF THE STRENGTH OF THE RESULTANT WIND BOUNDARY THIS AFTN AND EARLY EVENING. SIGNIFICANT SEAS WILL BE RIGHT AT 3 FT FROM CAPE FEAR NORTHWARD...AND 2 TO 3 FT SOUTH OF CAPE FEAR TO SOUTH SANTEE RIVER. WILL OBSERVE A BUILDING TREND TO SIGNIFICANT SEAS AS ILLUSTRATED BY WAVEWATCH3 AND LOCALLY RUN NWP IN RESPONSE TO THE INCREASING E-ESE FETCH. COULD SEE 4 FOOTERS BY DAYBREAK FRI ACROSS THE WATERS OFF CAPE FEAR. PERIODS WILL RANGE FROM 7 TO 9 SECONDS...AND COULD BE CONSIDERED A SWELL RATHER THAN JUST WIND DRIVEN WAVES. A CHOP WILL DEVELOP ACROSS THE INSHORE WATERS THIS AFTN/EARLY EVENING FROM THE INLAND PROGRESSING RESULTANT WIND BOUNDARY. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 AM THURSDAY... THE PRESSURE GRADIENT WILL BE QUITE WEAK ON FRIDAY AS HIGH PRESSURE WILL BE WEAKLY SPRAWLED WEST TO EAST ACROSS THE ATLANTIC MAINLY OFF THE ATLANTIC COAST. NORMALLY SUCH LIGHT FLOW (CAPPED AT 10 KT) WOULD LEAD TO VERY DIMINUTIVE SEAS. HOWEVER THE EASTERLY FETCH WILL BE LONG ENOUGH TO BRING SOME LONGER PERIOD WAVE ENERGY INTO MOST OF THE REGION. DOMINANT WAVE PERIODS ARE FORECAST TO BE 9 SECONDS. NEARSHORE PORTIONS OF BRUNSWICK ZONES WILL BE A BIT SHADOWED FROM THE SWELLS. THE ONLY DISCERNIBLE DIFFERENCE HEADING INTO SATURDAY APPEARS TO BE A SLIGHT RETREAT OF THE RIDGE AXIS BRINGING A SOUTHEASTERLY FLOW AS OPPOSED TO SOUTHEAST. LONG TERM /SUNDAY THROUGH MONDAY/... AS OF 3 AM THURSDAY... THE CONTINUED GRADUAL RETREAT OF WEST ATLANTIC HIGH PRESSURE RIDGE AXIS WILL LEAD TO A SLOW VEERING THROUGH THE PERIOD. WIND SPEEDS WILL REMAIN LIGHT...GENERALLY 10 KTS OR LESS. THERE WILL LIKELY NOT BE MUCH CHANGE IN THE SEAS ALTHOUGH THE BREAKING DOWN OF THE FETCH MAY DECREASE THE SWELL ENERGY. THIS WILL BE SLIGHT HOWEVER AND MAY ONLY MANIFEST AS A SMALL DECREASE IN WAVE PERIOD RATHER THAN PREDOMINANT WAVE HEIGHT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...DCH SHORT TERM...MBB/SRP LONG TERM...MBB AVIATION...MRR

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