000
FXUS62 KILM 190546
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
147 AM EDT WED JUN 19 2013

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST AS A COLD
FRONT SLOWLY SAGS ACROSS THE AREA TODAY. DRY HIGH PRESSURE WILL
BUILD IN FROM THE NORTH BEHIND THE FRONT TONIGHT AND THURSDAY. THE
FRONT WILL WEAKEN TO THE SOUTH LEAVING A TROUGH OF LOW PRESSURE
WHICH MAY MOVE BACK TOWARD THE COAST AND AFFECT THE AREA THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 730 PM TUESDAY...COLD FRONT WAS LOCATED NEAR A GSO-HKY LINE
AT 21Z. AIRMASS AHEAD OF THE FRONT REMAINS UNSTABLE...ESPECIALLY
CLOSE TO THE SE NC COAST WITH LI TO -6. ONGOING CONVECTION ACROSS
THIS REGION WILL LIKELY STRENGTHEN BRIEFLY ALONG THE SEA
BREEZE...THEN WEAKEN AS IT MOVES OVER THE MARINE LAYER. FOR THE
REMAINDER OF THE NIGHT...WILL CARRY CHANCE POPS AS THE FRONT
SLOWLY MAKES ITS WAY ACROSS THE CWA AND STALLS ALONG THE COAST.
THIS WILL ACT AS A FOCUS FOR CONVECTION AGAIN WEDNESDAY AFTERNOON.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...FRONT ALIGNED RIGHT ALONG THE CAROLINA
COAST WED MORNING. AS MID TO UPPER TROUGH MOVES SLOWLY EAST THE
WINDS REMAIN SW ALOFT ALLOWING FOR FRONT TO MOVE VERY SLOWLY
TOWARD THE SOUTHEAST THROUGH THE PERIOD. THIS WILL ALSO MAINTAIN
SOME MID TO UPPER LEVEL ENERGY ALONG THE COASTAL CAROLINAS THROUGH
WEDNESDAY. THE SEA BREEZE WILL ALSO PROVIDE SOME ADDITIONAL
CONVERGENCE WED AFTN AND THEREFORE EXPECT ACTIVE WEATHER MAINLY
ALONG THE COAST. PCP WATER VALUES WILL BE CONCENTRATED ALONG THE
SOUTHEAST COAST WITH VALUES OVER 2 INCHES. A VERY TIGHT MOISTURE
GRADIENT WILL DEVELOP AS DRIER HIGH PRESSURE ADVECTS IN FROM THE
NORTH TO NORTHWEST BEHIND THE FRONT. INLAND AREAS COULD SEE A VERY
DRY AND SUNNY DAY BUT WITH THE FRONT LINED UP ALONG THE
COAST...WILL KEEP PCP ACROSS MOST OF LOCAL CWA WITH HIGHEST POPS
ALONG THE COAST. AS FOR TEMPS...A SLIGHT COOLING BEHIND FRONT AND
CLOUDS AND PCP ALONG FRONT WILL KEEP TEMPS BELOW NORMAL FOR THE
MOST PART. EXPECT HIGHS IN THE 80 TO 83 RANGE CLOSER TO THE COAST
AND AROUND 85 FURTHER INLAND. TEMPS WED NIGHT SHOULD BE BETWEEN 65
AND 70.

BY THURS THE FRONT SHOULD PUSH FAR ENOUGH SOUTH AND EAST TO ALLOW
FOR A DRY DAY. LIGHT NORTHERLY WINDS WILL CARRY IN DRIER AND
SLIGHTLY COOLER AIR AS HIGH PRESSURE NOSES DOWN FROM THE
NORTHEAST. PCP WATER VALUES WILL DROP DOWN TO LESS THAN AN INCH
ACROSS INLAND AREAS. OVERALL EXPECT CLEARING SKIES AND PLENTY OF
SUNSHINE ON THURSDAY WITH TEMPS RUNNING SLIGHTLY BELOW
NORMAL...HIGHS IN THE MID 80S AND LOWS IN THE MID 60S FOR THE MOST
PART.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...A WARMING TREND WITH MORE TYPICAL SUMMER-LIKE
CONDITIONS EXPECTED AS WE OFFICIALLY ENTER CLIMATOLOGICAL
SUMMER...WITH THE SUMMER SOLSTICE OCCURRING EARLY FRIDAY MORNING
HERE IN THE CAROLINAS. WHILE MUCH OF THE PERIOD WILL FEATURE
BUILDING MID-LEVEL RIDGING AND A BERMUDA SURFACE HIGH COMBINING TO
CREATE TEMPS NEAR-TO-SLIGHTLY-ABOVE NORMAL AND DIURNAL CONVECTIVE
CHANCES...THE BEGINNING OF THE PERIOD IS SLIGHTLY MORE UNCERTAIN.

WHILE AN ELONGATED AREA OF HIGH PRESSURE WILL ARCH DOWN FROM THE
NORTHEAST COAST FRIDAY AND SATURDAY BEFORE MIGRATING TO A
BERMUDA-RIDGE POSITION...THIS WILL GENERALLY CREATE VERY DRY AIR
ACROSS THE REGION. HOWEVER...GFS/ECMWF BOTH SUGGEST A COASTAL TROUGH
JUST OFFSHORE THE CAROLINAS TRYING TO ADVECT ONSHORE SATURDAY AS
SYNOPTIC FLOW BECOMES EASTERLY AROUND MIGRATING SURFACE HIGH. WITH
BUILDING HEIGHTS ALOFT AND VERY DRY ANTECEDENT AIR...DO NOT EXPECT
WIDESPREAD PRECIP WITH THIS FEATURE. HOWEVER...WILL INCREASE POP
ESPECIALLY NEAR THE COAST...BUT KEEP CAPPED AT LOW-CHC.

AS ANY REMNANT COASTAL TROUGH ERODES LATE SATURDAY...BERMUDA RIDGING
BECOMES DOMINANT SUN-TUE WITH INCREASING TEMPS AND TYPICAL DIURNAL
CONVECTIVE CHANCES. WITH HEIGHTS BUILDING ALOFT AT THE SAME
TIME...THIS WILL SUPPRESS WIDESPREAD CONVECTION...AND THUS WILL KEEP
POP ONLY AT SCHC/SILENT FOR THE REMAINDER OF THE EXTENDED.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...HAVE INCLUDED VCSH TO ACCOUNT FOR SHOWERS SLOWLY SAGGING
SOUTH ALONG AND AHEAD OF A COLD FRONT. MVFR/TEMPO IFR CIGS ARE
POSSIBLE THROUGH SUNRISE...THOUGH CONFIDENCE IS LOW ATTM. THE FRONT
IS EXPECTED TO STALL NEAR THE COAST TODAY...AND MORE SHOWERS AND
THUNDERSTORMS APPEAR LIKELY LATER TODAY...ESPECIALLY FOR THE COASTAL
TERMS. WINDS MAY BE LIGHT AND VARIABLE ALONG THE COAST NEAR THE
STALLED BOUNDARY. EXPECT PREVAILING VFR DURING THE DAY WITH TEMPO
MVFR/IFR IN THE HEAVIEST DOWNPOURS. PCPN CHANCES DIMINISH AFTER
00Z...THOUGH SHOWERS COULD LINGER INTO THE EVENING HOURS ALONG THE
COAST.

EXTENDED OUTLOOK...VFR THURSDAY THROUGH SATURDAY. SLIGHT CHANCE OF
SHOWERS ON SUNDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM TUESDAY...STRONG CONVECTION WILL MOVE OFF THE SE NC
COAST EARLY THIS EVENING AND IS EXPECTED TO WEAKEN. ALTHOUGH THERE
WILL BE A LULL IN TSTM ACTIVITY FOR A FEW HOURS...THE CHANCES WILL
INCREASE AGAIN AFTER MIDNIGHT WITH THE APPROACH OF A COLD FRONT.
THE FRONT WILL STALL OUT NEAR THE COAST BY DAWN WEDNESDAY.

TIGHTENING GRADIENT IN ADVANCE OF THIS FRONT WILL PUSH SWLY WINDS
INTO THE 15 TO 20 KT RANGE OVERNIGHT. SEAS WILL BUILD AS A
RESULT...WITH 4 TO 6 FT SEAS OVER OUR NC WATERS AND 3 TO 5 FT DOWN
SOUTH. A SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT FOR NC
WATERS AND EXERCISE CAUTION STATEMENTS FOR OUR SC WATERS.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...COLD FRONT WILL LINE UP JUST OVER THE
WATERS ALONG THE CAROLINA COAST EARLY WED. TO THE WEST AND NORTH
OF THE FRONT THE WINDS WILL VEER TO THE NORTH TO NORTHEAST AND TO
THE SOUTH AND EAST OF THE FRONT THE WINDS WILL STAY W-SW. OVERALL
EXPECT STRONGER WESTERLY WINDS TO LIGHTEN UP RIGHT AROUND DAYBREAK
AS FRONT SLOWS ALONG COAST. WINDS WILL BE VARIABLE THROUGH THE DAY
ON WED WITH A LIGHT OFF SHORE FLOW CLOSE TO THE COAST AND W TO
SW WINDS IN THE OUTER WATERS THROUGH MOST OF WED. THE LIGHTER OFF
SHORE FLOW WILL ALLOW SEAS TO RELAX ESPECIALLY NEAR SHORE...DOWN
TO 1 TO 2 FT. SEAS IN THE OUTER WATERS WILL DROP BELOW SCA BUT
WILL HOLD UP IN STRONGER SW TO W FLOW UP AROUND 3 TO 4 FT WITH
SOME 5 FTERS IN OUTERMOST WATERS MOST OF THE DAY.

AS COLD FRONT PUSHES FARTHER SOUTH AND EAST THROUGH WED NIGHT INTO
THURS...A SURGE OF NORTHEAST WINDS UP TO A SOLID 15KTS WILL
DEVELOP. THIS WILL KEEP SEAS 3 TO 4 FT IN MOST WATERS EXCEPT SOUTH
OF CAPE FEAR WHERE WATERS WILL BE BLOCKED FROM NORTHEAST FLOW
KEEPING THE HEIGHTS AROUND 1 TO 2 FT.

LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...GUSTY NE WINDS TO START THE PERIOD AS AN
ELONGATED AREA OF HIGH PRESSURE STRETCHES DOWN TO THE SOUTHEAST FROM
NEW ENGLAND. AT THE SAME TIME...DECAYING COLD FRONT OFFSHORE WILL
WAVER JUST OUTSIDE THE WATERS...THUS PINCHING THE GRADIENT AND
CREATING 15 KT NE WINDS FRIDAY AND EARLY SATURDAY. THIS FRONT/TROUGH
OFFSHORE WILL SLOWLY WORK BACK TOWARDS THE COAST SATURDAY INTO
SUNDAY AS HIGH PRESSURE MIGRATES OFFSHORE TURNING THE PREDOMINANT
FLOW TO THE E/SE...WITH EASING SPEEDS...FALLING TO 10 KTS OR LESS.
SEAS THROUGH THE PERIOD WILL BE FORMED THROUGH A COMBINATION OF A SE
GROUND SWELL AND A WIND CHOP...NE ON FRIDAY AND SOUTHERLY SAT/SUN.
SEAS WILL BE 2-4 FT FRIDAY AND SATURDAY...FALLING TO 1-3 FT ON
SUNDAY.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR AMZ250-252.

&&

$$
NEAR TERM...CRM
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...BJR/RJD