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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 220325
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1125 PM EDT MON JUL 21 2014

.SYNOPSIS...
A STATIONARY FRONT STALLED ACROSS THE INTERIOR CAROLINAS WILL SLOWLY
DISSIPATE TONIGHT AND TUESDAY. BERMUDA HIGH PRESSURE WILL BUILD INTO
THE AREA WEDNESDAY AND THURSDAY. A COLD FRONT WILL APPROACH FROM THE
NORTHWEST LATE IN THE WEEK AND STALL NORTH OF THE AREA FOR THE
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
AS OF 1100 PM MONDAY...THE SPICKET CONTINUES TO SLOWLY AND
TEMPORARILY TURN OFF ACROSS THE ILM CWA. WITH THE LOSS OF DAYTIME
HEATING...AND FORCING FROM RESIDUAL COLLIDING OUTFLOW BOUNDARIES
HAVING BEEN WORKED OVER...PCPN COVERAGE AND INTENSITY ACROSS THE
ILM CWA HAS BEEN ON THE DECLINE. MUCH OF THE PCPN ACROSS THE FA
HAS BECOME STRATIFORM IN NATURE...AND IS WELL EXHIBITED BY THE
LATEST LOCAL KLTX...AND MOSAIC RADAR TREND DISPLAYS. WILL
INITIALLY LOWER POPS TO ISOLATED OR LOW CHANCE DURING THE
REMAINDER OF THIS EVENING AND INTO THE PRE-DAWN TUE HOURS.
MODELS HINT AT RAMPING CONVECTIVE TYPE POPS BACK UPWARDS ACROSS
THE ADJACENT ATL WATERS OVERNIGHT. MODELS THEN EVENTUALLY
DRIFT/MOVE THIS PCPN PARTIALLY ONSHORE IN THE VICINITY OF THE SFC
COASTAL TROF/FRONT. HAVE ADJUSTED POPS TO ACCOMODATE THIS
POTENTIAL ACTIVITY DURING THE MID TO LATE PRE-DAWN AND EARLY
DAYLIGHT TUE HOURS.

CURRENT TEMPS ACROSS THE ILM CWA ARE UNDER THE INFLUENCE OF RAIN-
COOLED AIR...WITH WIDESPREAD 70S BEING REPORTED. LATEST MODEL MOS
GUIDANCE INDICATES TONIGHTS LOWS ARE NOT TOO FAR FROM CURRENT
VALUES...ESPECIALLY WITH SFC DEWPOINTS PROGGED TO HOLD IN THE LOW
TO MID 70S OVERNIGHT.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...DEEP MOISTURE SHOULD CONTINUE TO BE CHANNELED
INTO THE COASTAL CAROLINAS ON TUESDAY. DEEPENING UPPER LOW TO OUR
WEST WILL BE RETROGRADING SLIGHTLY WHILE RIDGE OFFSHORE BUILDS
SLIGHTLY. MODELS SHOW LONG FETCH SOUTHERLY FLOW AT THE SURFACE WITH
A COASTAL TROUGH EARLY IN THE DAY THAT MIGRATES INLAND AS THE DAY
WEARS ON. THE WRF IN PARTICULAR IMPLIES THAT CONVECTIVE COVERAGE AND
QPF PROSPECTS MAY MIRROR THOSE OF TODAY WITH FORECAST PRECIPITABLE
WATERS STAYING AS ELEVATED AS THEY ARE NOW OR EVEN INCREASING
SLIGHTLY TO 2.25" AND ALTHOUGH THE STRONGER MID LEVEL VORTS
PORTRAYED IN THE WRF HAVE THE LOOK OF CONVECTIVE FEEDBACK ANALYSIS
OF LOW LEVEL POTENTIAL VORTICITY FIELDS SHOW NO SPURIOUS DATA TO
INDICATE SUCH. WEDNESDAY IS A BIT OF A TRANSITIONAL DAY...BUT COULD
READILY SEE HOW THE AFTERNOON OFFERS UP HIGHER THAN NORMAL COVERAGE
OF STORMS ALBEIT LESSER THAN TODAY/TUESDAY. THE MAIN UPPER LOW TO
OUR WEST CONTINUES TO RETROGRADE BUT WE STILL HAVE A MID LEVEL
SOUTHERLY COMPONENT...USUALLY A GOOD INDICATOR FOR AN  ACTIVE
DAY...ESPECIALLY WITH LITTLE IMPETUS FOR LOW LEVELS TO DRY OUT MUCH.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
.
AS OF 300 PM MONDAY...LONGWAVE TROUGH EXPANDING ACROSS THE EAST WILL
CAPTURE A RETROGRADING CLOSED 500MB LOW OVER THE GULF COAST LATE IN
THE WEEK...AND SWING IT BACK TO THE NORTHEAST. THIS WILL LEAVE BROAD
TROUGHING ACROSS THE EAST THROUGH THE WKND. BENEATH THIS TROUGH...A
COLD FRONT WILL DROP SLOWLY SOUTHEAST...REPLACING THE HIGH PRESSURE
RIDGE THAT WILL BE OVER THE AREA FROM MID-WEEK. WITH STRONG MOIST
ADVECTION AHEAD OF THIS BOUNDARY...AND WAVES OF LOW PRESSURE
EXPECTED TO DEVELOP ALONG IT...THU/FRI SHOULD ONCE AGAIN FEATURE
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS...WITH TEMPS AROUND
CLIMO BOTH DAYS. THE COLD FRONT DRIFTS OFFSHORE FOR THE
WKND...LEAVING A DRIER COLUMN...BUT STILL TYPICAL SUMMERTIME
CONVECTION CHANCES AND TEMPS JUST BELOW NORMAL. BEYOND THE WEEKEND
DURING EARLY NEXT WEEK...SIGNALS POINT TO A STRONG RE-AMPLIFICATION
OF THE MID-LEVEL PATTERN WITH AN ANOMALOUSLY DEEP TROUGH ACROSS THE
EAST. THIS COULD BRING A RENEWED PERIOD OF BELOW NORMAL TEMPS AND
ABOVE NORMAL PRECIP CHANCES BEGINNING MONDAY.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...COVERAGE OF -RA IS FINALLY DIMINISHING ACROSS OUR CWA
THIS EVENING AFTER A DAY OF LOCALLY HEAVY RAINFALL. CONDITIONS RANGE
FROM VFR ALONG THE COAST TO PATCHY IFR INLAND WHERE MORE PERSISTENT
RAIN HAS CREATED IFR CIGS. TEMPO IFR CIGS MAY BRIEFLY CONTINUE
INLAND THIS EVENING...BUT CIGS SHOULD IMPROVE TO MVFR/VFR LEVELS AS
THE RAIN SUBSIDES TONIGHT. GIVEN THE MOIST GROUND CONDITIONS AND
LIGHT TO CALM WINDS OVERNIGHT...MORE FOG/STRATUS WILL LIKELY
RE-DEVELOP EARLY TUESDAY MORNING. DEBRIS CLOUDS SHOULD KEEP VSBYS
MVFR...BUT IFR STRATUS MAY BECOME AN ISSUE ESPECIALLY AT THE INLAND
TERMINALS. WILL MAINTAIN VCSH ALONG THE COAST TUESDAY MORNING AS
MORE SHOWERS ASSOCIATED WITH A COASTAL TROUGH MOVE ONSHORE. AS THIS
TROUGH PUSHES INLAND DURING THE DAY...SHOWERS/ISO TSTMS WILL
INCREASE IN COVERAGE AND WINDS WILL BECOME SOUTHEAST AOB 10 KTS.

EXTENDED OUTLOOK...CHANCE OF SHOWERS/TSTMS WILL PERSIST THROUGH THE
EXTENDED PERIOD. EXPECT PREDOMINANTLY VFR CONDITIONS WITH TEMPO
PERIODS OF MVFR/IFR CIGS/VSBYS IN STORMS.

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 1115 PM MONDAY...LOCAL BUOY REPORTS/TRENDS INDICATE A RATHER
SOLID 2 TO 3 FOOT ESE GROUND SWELL...EXHIBITING 7 TO 9 SECOND
PERIODS. THIS WILL CONTINUE TO AFFECT THE AREA WATERS OVERNIGHT
INTO DAYLIGHT TUESDAY. WITH AN OSCILLATING SFC BOUNDARY ACROSS
THE ILM COASTAL WATERS TONIGHT INTO TUE...WINDS HAVE BECOME
SOMEWHAT DIFFICULT IN IDENTIFYING A PREDOMINATE DIRECTION. THE SFC
PG ACROSS THE LOCAL WATERS REMAINS CONDUCIVE TO WIND SPEEDS AT 5
TO 10 KT. AS FOR DIRECTIONS...THE LATEST SFC PRESSURE PATTERN TO
SUPPORT E TO SE DIRECTIONS ACROSS THE AREA WATERS.

CONVECTION TO INCREASE IN AREAL COVERAGE AND INTENSITY ACROSS THE
WARM ATL COASTAL AND OFFSHORE WATERS OVERNIGHT. AND WILL HAVE A
TENDENCY TO DRIFT/MOVE TOWARD THE NW AND LIKELY PARTIALLY ONSHORE
DURING THE AM HOURS OF TUE.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...TUESDAY BRINGS A PREDOMINANTLY SOUTHEASTERLY
WIND AS A SURFACE TROUGH INITIALLY NEAR THE COAST MOVES INLAND WHILE
WEST ATLANTIC HIGH PRESSURE REMAINS NEARLY STATIONARY. SPECTRAL WAVE
BULLETINS SHOW THAT A GENERAL 3 FT DOMINANT SEA STATE TO BE A NEARLY
SINGULAR 7 SECOND WAVE SET. A MORE TYPICAL PIEDMONT TROUGH SETS UP
ON THURSDAY AND THE ATLANTIC HIGH DOES APPEAR TO FLEX WESTWARD
CLOSER TO THE COAST A BIT. THIS SHOULD BE GOOD FOR ABOUT A 5KT
INCREASE IN THE RANGE OF WAVE HEIGHTS AND SHOULD INTRODUCE A 4 FT
WIND WAVE TO MOST ZONES.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...PINCHED GRADIENT BETWEEN OFFSHORE HIGH
PRESSURE AND A SLOWLY APPROACHING COLD FRONT FROM THE NW WILL DRIVE
SW WINDS UP TO 15-20 KTS THURSDAY AND MUCH OF FRIDAY. THIS FRONT IS
EXPECTED TO CROSS OVER THE WATERS VERY LATE FRIDAY WITH A WIND SHIFT
TO THE WEST...AND A SPEED REDUCTION TO LESS THAN 10 KTS. THIS WILL
BE SHORT LIVED HOWEVER...AS THE FRONT PUSHES BACK TO THE NORTH BY
THE END OF THE PERIOD WITH A RETURN OF SW WINDS. SEAS THU/FRI WILL
RISE TO 4-5 FT AT TIMES THANKS TO THESE STRONGER WINDS AND A SE
GROUND SWELL...AND CAUTIONARY STATEMENTS MAY BE REQUIRED.
THE WATERS WILL FEATURE LOWER AMPLITUDE SEAS ON SATURDAY OF 2-3
FT.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...JDW
AVIATION...BJR