-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 190719
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
319 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 TONIGHT/...
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AS OF 3 AM WEDNESDAY...NUMEROUS SHOWERS AND SOME THUNDERSTORMS WERE
MOVING ACROSS PORTIONS OF THE FORECAST AREA JUST AHEAD OF A COLD
FRONT. THE COLD FRONT WILL SLOWLY SLIP INTO OUR NORTHERN ZONES PRIOR
TO SUNRISE...THEN SLOWLY SAG S ACROSS THE FORECAST AREA THROUGH THE
DAY. MODELS ARE STILL SHOWING WEAK WAVES OF LOW PRESSURE DEVELOPING
ALONG THE FRONT AND THIS WILL SERVE TO FURTHER SLOW ITS PROGRESS
SOUTHWARD. A RATHER POTENT MID-LEVEL SHORTWAVE WILL PASS LARGELY TO
THE SOUTH OF THE FORECAST AREA TONIGHT AS HIGH PRESSURE TO OUR N
ATTEMPTS TO WEDGE SOUTHWARD ACROSS THE CAROLINAS. WINDS ARE EXPECTED
TO SHIFT TO THE N AND THEN NE BEHIND THE FRONT TODAY...LASTLY ACROSS
MYRTLE BEACH AND GEORGETOWN LATE DAY AND THIS EVE.

PRECIPITABLE WATER VALUES WILL TOP 2 INCHES TODAY...TRENDING SLOWLY
LOWER DURING THE COURSE OF THE DAY FROM N TO S. THE DRY AIR WILL
BECOME MORE FIRMLY ESTABLISHED INLAND TONIGHT...BUT IT WILL BE MUCH
TOUGHER TO MAKE ANY SIGNIFICANT INROADS ALONG THE COAST. SIGNIFICANT
BREAKS IN THE CLOUD COVER SHOULD DEVELOP INLAND TONIGHT...ESPECIALLY
ACROSS THE NORTHERN PEE DEE THROUGH LBT AND EYF.

THICK CLOUD COVER WILL GREATLY LIMIT THE MAGNITUDE OF INSTABILITY
AND SO NO SEVERE WEATHER IS EXPECTED TODAY. HOWEVER...STORM MOTIONS
WILL BE UNDER 10 KT AND WITH SUCH A MOIST ENVIRONMENT...TORRENTIAL
DOWNPOURS ARE EXPECTED. WILL HIGHLIGHT HEAVY RAIN. WILL INDICATE THE
HIGHEST POPS ALONG AND AHEAD OF THE FRONT WITH POPS SLOWLY TRENDING
LOWER ON THE DRIER SIDE OF THE BOUNDARY. WILL CARRY POPS AS HIGH AS
LIKELY TO LOW-END CATEGORICAL TODAY. POPS WILL TREND LOWER THROUGH
THE NIGHT...BUT WILL CARRY LIKELY POPS ALONG THE COAST INTO THE EVE.
THE RISK FOR SHOWERS IS EXPECTED TO END FROM NNW TO SSE DURING THE
EVE...WITH ONLY A SMALL RISK ALONG THE COAST AND ALONG THE SOUTH
SANTEE RIVER OVERNIGHT.

HIGH TEMPERATURES SHOULD BE RATHER UNIFORM ACROSS THE AREA...LOWER
TO MID 80S WITH HIGH HUMIDITY LEVELS. DEWPOINTS SHOULD BEGIN TO
LOWER ACROSS N/NW ZONES LATER TODAY AND MORE SO TONIGHT. LOWS
TONIGHT COULD VARY MORE SIGNIFICANTLY GIVEN A DRIER AIRMASS WILL BE
MAKING ITSELF FELT ACROSS PORTIONS OF THE AREA. LOWS SHOULD REACH
THE MID 60S ACROSS MANY INLAND AREAS WITH PERHAPS LOWER 70S HANGING
ON ACROSS PORTIONS OF THE COAST.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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AS OF 3 AM WEDNESDAY...HIGH PRESSURE RIDGES DOWN THE COAST DURING
THE PERIOD WHILE COLD FRONT REMAINS JUST OFF THE COAST. FIRST HALF
OF THE PERIOD SHOULD BE DRY AS WESTERLY FLOW ALOFT IN CONJUNCTION
WITH SLOWLY BUILDING 5H RIDGE HELPS DRY THE REGION OUT. AT THIS
POINT IT LOOKS LIKE THE DEEP MOISTURE ASSOCIATED WITH THE FRONT
REMAINS JUST OFFSHORE AND FORECAST SOUNDINGS DROP PRECIPITABLE
WATER VALUES CLOSE TO 1 INCH LATE THU AFTERNOON. LOW LEVEL
NORTHEAST FLOW WILL PROVIDE SOME LOW LEVEL MOISTURE WHICH IS
LIKELY TO MANIFEST ITSELF AS A SCATTERED TO BROKEN FLAT STRATOCU
DECK IN THE AFTERNOON. CLOUD COVER ALONG WITH THE NORTHEAST FLOW
WILL KEEP HIGHS BELOW CLIMO. CANNOT RULE OUT SOME LIGHT SPRINKLES
NEAR THE COAST FROM ACTIVITY MOVING ON SHORE BUT DEEP DRY AIR
SHOULD PREVENT ANYTHING MEASURABLE.

REINFORCING SHOT OF DRY AIR ARRIVES THU NIGHT BUT IS SHORT LIVED AS
STALLED BOUNDARY MOVES CLOSER TO THE COAST FRI MORNING. LOWS WILL
BE NEAR TO SLIGHTLY BELOW CLIMO THU NIGHT WITH SKIES CLEARING AND
LIGHT NORTHEAST FLOW CONTINUING.

FORECAST SOUNDINGS SHOW A RETURN OF DEEPER MOISTURE DURING THE DAY
FRI AS THE BOUNDARY TRIES TO MOVE ONSHORE. BOUNDARY BECOMES SOMEWHAT
DIFFUSE AT THIS POINT BUT MOISTURE ASSOCIATED WITH IT MOVES ONSHORE
DURING THE AFTERNOON AND EVENING...OPENING UP THE POSSIBILITY OF
SOME ISOLATED CONVECTION. GIVEN THE PROXIMITY TO THE DRY AIR AND THE
WEAK SUBSIDENCE DO NOT THINK COVERAGE WILL BE SIGNIFICANT BUT FEEL
IT DOES WARRANT A SLIGHT CHC POP...MAINLY CONFINED TO COASTAL
COUNTIES. DESPITE CONTINUED NORTHEAST FLOW MORE SUN SHOULD LEAD
TO HIGHS A LITTLE CLOSER TO CLIMO. CLOUD COVER AND LOW LEVEL
MOISTURE ALONG THE COAST WILL CREATE A LARGER SPREAD FOR LOWS FRI
NIGHT. TEMPS WILL RANGE FROM NEAR TO SLIGHTLY ABOVE CLIMO ALONG
THE COAST TO NEAR TO SLIGHTLY BELOW CLIMO WELL INLAND.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
AS OF 3 AM WEDNESDAY...UNCERTAINTY ABOUNDS FOR THE DURATION OF THE
LONG TERM. THE DECENT AGREEMENT SEEN LAST NIGHT HAS EVAPORATED
LEAVING SEVERAL POSSIBLE SOLUTIONS TO PONDER. THESE RANGE FROM
MOSTLY DRY FOR THE WEEKEND AND START OF NEXT WEEK TO VERY WET WITH
POSSIBLE FOR WEAK LOW PRESSURE ALONG THE CAROLINA COAST. COMMON
THEME AMONG THEM IS THE EVOLUTION OF THE MID LEVEL AND SURFACE
PATTERNS AND THE PRESENCE OF LINGER SURFACE BOUNDARY OFF THE
SOUTHEAST COAST. ALL OF THE GUIDANCE SHOW MID LEVEL RIDGE BUILDING
OVER THE SOUTHEAST WHILE AT THE SURFACE BERMUDA HIGH TAKES HOLD.

THE KEY TO THE PERIOD WILL BE HOW DEFINED THE BOUNDARY REMAINS AND
HOW MUCH DEEP MOISTURE LINGERS WHEN THE BOUNDARY COMES ONSHORE AND
THEN LIFTS NORTH. THE ECMWF IS CURRENTLY THE DRIEST AND ALSO THE
SOLUTION WITH THE LEAST AMOUNT OF QUESTIONS CONCERNING ITS VALIDITY.
THE GFS APPEARS TO BE AFFECTED BY FEEDBACK WHICH MAY BE HELPING
MAINTAIN A STRONGER SURFACE BOUNDARY AND DEEPER MOISTURE. THE
CANADIAN DEVELOPS A CLOSED LOW WHICH MAY OR MAY NOT IMPACT THE
CAROLINAS...DEPENDING ON THE RUN. THIS HAS BEEN SOMEWHAT COMMON
FOR THE CANADIAN RECENTLY AS IT HAS BEEN TRYING TO TURN WEAK WAVES
ALONG STALLED COASTAL FRONTS INTO MORE SIGNIFICANT CLOSED LOWS
WITH LITTLE SUCCESS. FOR NOW WILL IGNORE ITS SOLUTION GIVEN
RECENT PERFORMANCES AND THE LACK OF CONSISTENCY. THE RESULT IS
MINIMAL CHANGES TO PREVIOUS FORECAST WITH SLIGHT CHC TO LOW CHC
POP EACH DAY AND TEMPERATURES GRADUALLY INCREASING FROM BELOW
CLIMO TO ABOVE CLIMO BY THE END OF THE PERIOD.
-- End Changed Discussion --

&&

.AVIATION /07Z 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...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM WEDNESDAY...SW WINDS WILL SHIFT TO N AND THEN NE AS A
COLD FRONT SLOWLY SAGS S ACROSS THE WATERS TODAY. THE NORTHERN
WATERS ARE EXPECTED TO SEE THE WIND SHIFT THIS MORNING THROUGH EARLY
AFTERNOON WHILE THE SOUTHERN WATERS WILL EXPERIENCE THE WIND SHIFT
DURING THE LATER AFTERNOON AND EVE HOURS. A NE SURGE WILL ACTUALLY
WORK ITS WAY DOWN THE COAST OVERNIGHT. THE STRONGEST WINDS WILL
OCCUR THIS MORNING AHEAD OF THE FRONT...MAINLY EARLY AND THEN IN THE
NE SURGE OVERNIGHT AND THU MORNING...UP TO 15 TO 20 KT ACROSS THE
NORTHERN WATERS AND NEAR 15 KT ACROSS THE SOUTHERN WATERS. SEAS WILL
TREND LOWER THROUGH THE DAY AND THEN REVERSE HIGHER OVERNIGHT. WILL
CAP SEAS AT 5 FT ACROSS THE NORTHERN WATERS AND 4 FT ACROSS THE
SOUTHERN WATERS. WILL HEADLINE SMALL CRAFT SHOULD EXERCISE CAUTION
FOR THE NORTHERN WATERS THIS MORNING WITH NO HEADLINES FOR THE
SOUTHERN WATERS. A HEADLINE MAY AGAIN BE REQUIRED LATE TONIGHT FOR
PORTIONS OF THE WATERS.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...PINCHED GRADIENT BETWEEN HIGH PRESSURE
BUILDING SOUTH AND STALLED FRONT OFF THE COAST WILL PRODUCE
NORTHEAST FLOW IN THE 15 TO 20 KT RANGE THU AND THU NIGHT. GRADIENT
STARTS TO WEAKEN LATE THU NIGHT WITH SPEEDS DROPPING TO A SOLID 15
KT BY FRI MORNING. FURTHER REDUCTION IN GRADIENT FRI WILL KEEP
NORTHEAST FLOW IN THE 10 TO 15 KT RANGE. FLOW BECOMES A LITTLE MORE
EASTERLY FRI NIGHT AS SURFACE RIDGE AXIS STARTS TO SETTLE SOUTH.
GRADIENT CONTINUES TO WEAKEN AS REMAINS OF STALLED FRONT LIFT INTO
THE AREA. AS A RESULT SPEEDS WILL DROP BELOW 10 KT BY THE END OF
THE PERIOD. SEAS 3 TO 5 FT THU IN RESPONSE TO STRONG NORTHEAST
FLOW SLOWLY SUBSIDE INTO FRI. GRADUALLY REDUCTION IN WINDS LATE
THU NIGHT AND FRI ALLOWS SEAS TO FALL TO 2 TO 3 FT BY THE END OF
THE PERIOD.

LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...WEAK COASTAL TROUGH IN THE VICINITY AND HIGH
PRESSURE WEAKLY BUILDING DOWN THE COAST DURING THE PERIOD WILL KEEP
WIND LIGHT AND VARIABLE. WINDS WILL BE FROM THE EAST AT 10 KT OR
LESS BUT COULD VARY FROM NORTHEAST TO SOUTHEAST AT ANY GIVEN
TIME...DEPENDING ON THE POSITION OF THE REMAINS OF THE SURFACE
BOUNDARY AND ANY MESOSCALE BOUNDARIES. LIGHT WIND FIELD WILL
MAINTAIN 2 TO 3 FT SEAS WITH HIGHEST SEAS SAT.
-- End Changed Discussion --

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
SC...NONE.
NC...NONE.
MARINE...NONE.
-- End Changed Discussion --

&&

$$

NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...BJR/RJD