-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 151810
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
210 PM EDT WED MAY 15 2013

.SYNOPSIS...
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.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 2 PM WEDNESDAY...BREEZY AND WARM CONDITIONS WILL CONTINUE
THROUGH THIS AFTERNOON AS TEMPS IN THE 80S ACROSS MUCH OF THE AREA
EXCEPT ALONG THE COAST. GUSTY SOUTHWEST WINDS WILL CONTINUE
THROUGH THIS EVENING AS HIGH PRESSURE REMAINS ANCHORED TO THE EAST AND
LOW PRESSURE SYSTEM PASSES TO THE NORTH. THE TIGHTENED GRADIENT
WILL PRODUCE SW WINDS GUSTING OVER 20 MPH THROUGH THIS AFTERNOON.
850 TEMPS WILL RISE UP TO 18C AS MID TO UPPER RIDGE BUILDS
OVERHEAD.  PCP WATER VALUES AROUND .75 INCHES DO INCREASE ABOVE
AN INCH THROUGH TONIGHT AS SOME OF THE MOISTURE ASSOCIATED WITH
SYSTEM TO THE NORTH REACHES DOWN OVER THE RIDGE INTO NORTH
CAROLINA. THIS MAY PRODUCE A FEW MID TO HIGH CLOUDS OVER THE
AREA...BUT OVERALL EXPECT CLEAR SKIES THROUGH TONIGHT. SEA BREEZE
WILL COME AGAINST STRONG SOUTHWEST WIND BUT WILL MAKE ITS WAY IN
FROM THE BEACHES LATER THIS AFTERNOON BRINGING LATE AFTERNOON
TEMPS DOWN SEVERAL DEGREES CLOSE TO THE COAST.

MID TO UPPER RIDGE HOLDS OVER THE SOUTHEAST THROUGH TONIGHT
MAINTAINING DRY CONDITIONS WITH PLENTY OF SUBSIDENCE. SOUTHWEST
FLOW WILL CONTINUE AS LOW PRESSURE SYSTEM PASSES ACROSS THE
NORTHEAST WITH TROUGH RUNNING DOWN THROUGH INLAND CAROLINAS AND
HIGH PRESSURE HOLDING OFF SHORE. EXPECT WINDS TO DIMINISH THROUGH
THIS EVENING BUT REMAIN UP TO 5 TO 10 MPH THROUGH THE NIGHT IN
THIS TIGHTENED GRADIENT FLOW. THESE WINDS WILL HELP KEEP A FLOW OF
WARM AND MOIST AIR INTO THE AREA WITH DEWPOINT TEMPS RISING UP
CLOSE TO 60 F BY MORNING WITH OVERNIGHT LOWS HOLDING ABOVE 60
DEGREES.
-- End Changed Discussion --

&&

.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 /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 12Z...HIGH CONFIDENCE FOR VFR THROUGH THE FORECAST PERIOD.
WARM FRONT TO OUR NORTH WILL STAY THERE. ANY CLOUDS WILL LIKELY
REMAIN TO THE NORTH ALSO. STRONG SOUTHWEST GRADIENT TODAY WILL
INCREASE THE WINDS SIGNIFICANTLY BY MID TO LATE MORNING...WITH GUSTS
TO NEAR 30 KTS POSSIBLE. WINDS WILL DIMINISH DIURNALLY THIS
EVENING...BUT WILL LIKELY STAY ABOVE 10 KTS ALL NIGHT. THIS COMBINED
WITH DRY MOISTURE PROFILES WILL KEEP FOG AT BAY.

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

&&

.MARINE...
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NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...SOUTHWEST WINDS GUSTING UP TO 20 KTS THIS
MORNING IN TIGHTENING GRADIENT FLOW BETWEEN HIGH PRESSURE OFF
SHORE AND LOW PRESSURE SYSTEM PASSING BY TO THE NORTH. WINDS WILL
CONTINUE TO INCREASE THROUGH THIS AFTERNOON PUSHING WINDS AND SEAS
INTO SMALL CRAFT ADVISORY THRESHOLDS.

SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM NOON THROUGH 6AM THURS
MORNING. WINDS WILL INCREASE TO 20 TO 25 KTS THIS AFTERNOON...WITH
SEAS BUILDING TO 4 TO 6 FT. WNA SHOWS PEAK IN SEAS AROUND MIDNIGHT
TONIGHT WITH A STEADY DECREASE THEREAFTER AS GRADIENT RELAXES A
BIT WITH CONTINUED SW TO W FLOW 15 TO 20 KTS THROUGH EARLY
THURSDAY.

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.
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&&

.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR AMZ250-252-
     254-256.
-- End Changed Discussion --

&&

$$

NEAR TERM...RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...DL/RGZ