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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 150723 CCA
AFDILM

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE WILMINGTON NC
322 AM EDT WED MAY 15 2013

.SYNOPSIS...
-- Changed Discussion --
WARMER TEMPERATURES WILL DEVELOP TODAY AND CONTINUE THROUGH EARLY
NEXT WEEK AS HIGH PRESSURE PUSHES OFFSHORE. ISOLATED THUNDERSTORMS
WILL BE POSSIBLE STARTING FRIDAY AND CONTINUING THROUGH THE
WEEKEND.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...RAPID WARM-UP TODAY AND BREEZY AS
SOUTHWESTERLY GRADIENT TIGHTENS OVER THE EASTERN CAROLINAS. HIGH
PRESSURE OVER THE WESTERN ATLANTIC WILL SHOW LITTLE CHANGE IN
STRENGTH OR POSITION...HOWEVER A FRONTAL SYSTEM PASSING TO THE
NORTH WILL TIGHTEN THE GRADIENT OVER THE AREA...LEADING TO AN
INCREASINGLY WARM SWLY FLOW. IN ADDITION...SUBSIDENCE UNDER A
BUILDING UPPER RIDGE AND AMPLE SUNSHINE WILL AID IN WARMING TODAY.
DAYTIME TEMPERATURES WILL REBOUND BACK ABOVE NORMAL...WITH HIGHS
IN THE MID AND EVEN UPPER 80S MOST LOCATIONS EXCEPT AT THE COOLER
BEACHES. MODEL CONSENSUS HAS OVERNIGHT LOWS IN THE LOWER TO MID
60S.

THIS AFTERNOON WILL BE BREEZY AND GUSTY...WITH SWLY WINDS IN THE 15
TO 20 KT RANGE AND GUSTS UP TO 30 KTS.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM TUESDAY...SHORTWAVE MID LEVEL RIDGE EXITING TO THE EAST
THU WILL BE REPLACED BY WEAK TROUGHING FRI. DO NOT THINK PRECIP
WILL BE AN ISSUE ON THU DESPITE THE EXITING 5H RIDGE. FORECAST
SOUNDINGS SHOW ABUNDANT DRY AIR BELOW 15K FT ALONG WITH WEAK MID
LEVEL SUBSIDENCE. INCREASING MOISTURE ABOVE 15K FT LATE THU AND THU
NIGHT WILL BRING ABOUT AN INCREASE IN HIGH CLOUD.

DIURNAL CONVECTION WILL BE THE STORY FOR THE SECOND HALF OF THE
PERIOD AS A SUMMER TIME PATTERN TAKES SHAPE. DEEPER MOISTURE MOVES
INTO THE AREA WHILE AT THE SURFACE BERMUDA HIGH AND PIEDMONT TROUGH
BECOME THE DOMINANT FEATURES. WEAK FORCING ALONG THE SEABREEZE AND
THE PIEDMONT TROUGH IN CONJUNCTION WITH DIURNAL HEATING WILL LIKELY
LEAD TO AFTERNOON CONVECTION. FORECAST SOUNDINGS DO SHOW SOME
LINGERING DRY AIR IN THE MID LEVELS SO DO NOT THINK COVERAGE WILL BE
EXTENSIVE BUT LOW CHC POP IS PROBABLY WARRANTED WELL INLAND.

TEMPERATURES REMAIN ABOVE CLIMO THROUGH THE PERIOD. THU WILL BE
SLIGHTLY WARMER...ESPECIALLY NEAR THE COAST WHERE WESTERLY FLOW WILL
KEEP SEABREEZE PINNED.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM TUESDAY...BERMUDA HIGH AND PIEDMONT TROUGH CONTINUE TO BE
THE MOST SIGNIFICANT FEATURES IN THE REGION DURING THE PERIOD. WEAK
BACK DOOR COLD FRONT WILL TRY TO MOVE INTO THE AREA OVER THE
WEEKEND...BUT GIVEN THE TIME OF YEAR THIS IS LESS LIKELY. ECMWF
INSISTS ON PUSHING THE FRONT SOUTH OF THE AREA THIS WEEKEND BUT THE
GFS KEEPS IT STALLED JUST NORTH OF THE AREA. GIVEN THE GFS HAS BEEN
MARGINALLY BETTER THAN THE ECMWF RECENTLY AND THE CLIMATOLOGICAL
LIKELIHOOD OF THE FRONT REMAINING NORTH OF THE AREA HAVE FAVORED THE
GFS SOLUTION. MID LEVEL PATTERN REMAINS WEAK BUT PROGRESSIVE WITH
SOME AMPLIFICATION LATE IN THE PERIOD AS SHORTWAVE TROUGH MOVES INTO
THE UPPER MIDWEST. LOCALLY THE CONCERN WILL BE DIURNAL CONVECTION ON
BOTH THE PIEDMONT TROUGH AND THE SEABREEZE. BEST PRECIP CHANCES WILL
BE OVER THE WEEKEND AS LATE IN THE PERIOD SUBSIDENCE FROM 5H RIDGE
PROGGED TO BUILD OVER THE SOUTHEAST WORKS TO SUPPRESS CONVECTION.
TEMPERATURES WILL BE A FEW DEGREES ABOVE CLIMO THROUGH THE PERIOD.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...EXPECT VFR CONDITIONS AT ALL TERMS THROUGH THE VALID TAF
PERIOD. SOUTHWEST WINDS WILL REMAIN 5-10 KTS THROUGH 12Z WITH
20-30 KT WINDS JUST OFF THE SFC...AROUND 1-2KFT AGL. HAVE ADDED
LOW-LEVEL WIND SHEAR FOR KLBT/KFLO BEGINNING AT 06Z WHERE
FORECAST SOUNDINGS INDICATE THE LOW-LEVEL WINDS WILL BE STRONGEST.
SFC WINDS WILL PICK UP AFTER 12Z AS THE PRESSURE GRADIENT TIGHTENS
ACROSS THE CAROLINAS. SOUTHWEST WINDS 10-20 KTS AND GUSTS AROUND
25 TO 30 KTS LIKELY WILL PERSIST THROUGH THE DAY. THE GUSTS WILL
BEGIN SUBSIDING AFTER 00Z THURSDAY...BUT SOUTHWEST WINDS WILL
REMAIN 8-12 KTS THROUGH THE EVENING HOURS.

EXTENDED OUTLOOK...VFR LIKELY THROUGH FRIDAY. SLIGHT CHANCE OF
SHOWERS/TSTMS SATURDAY AND SUNDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...SMALL CRAFT ADVISORY REMAINS IN EFFECT
TODAY. A TIGHTENING GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND
LOW PRESSURE INLAND WILL ALLOW WINDS TO INCREASE TO 20 TO 25 KTS
TODAY...WITH SEAS BUILDING TO 4 TO 6 FT. SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT THROUGH THE OVERNIGHT HOURS.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM TUESDAY...SOUTHWEST FLOW AROUND WEST SIDE OF BERMUDA HIGH
STARTS OUT 15 TO 20 KT BUT AS SURFACE GRADIENT SLOWLY RELAXES THU
AFTERNOON SPEEDS DROP TO 15 KT. REDUCTION IN SPEEDS CONTINUES INTO
FRI WITH 10 TO 15 KT BY DAYBREAK. WINDS REMAIN SOUTHWEST THROUGH THE
END OF THE PERIOD WITH BERMUDA HIGH THE DOMINANT SURFACE FEATURE.
BORDERLINE SCA SEAS AT THE START OF THE PERIOD MAY REQUIRE EXTENSION
OF HEADLINES THROUGH THU MORNING BUT BY MIDDAY SEAS SHOULD BE 3 TO 5
FT...FALLING TO 2 TO 3 FT FOR FRI AND FRI NIGHT.

LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM TUESDAY...BERMUDA HIGH AND PIEDMONT TROUGH COMBO WILL
KEEP WINDS SOUTH TO SOUTHWEST THROUGH THE PERIOD. SPEEDS WILL BE 10
TO 15 KT...HIGHEST IN THE AFTERNOON AS PIEDMONT TROUGH BECOMES MORE
DEFINED AND SEABREEZE DEVELOPS. SEAS WILL RUN 2 TO 4 FT...A MIX OF
WIND WAVE AND SOUTHERLY SWELL.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 AM EDT THURSDAY FOR
     AMZ250-252-254-256.

&&

$$

NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...BJR