-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 171921
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
321 PM EDT MON JUN 17 2013

.SYNOPSIS...
-- Changed Discussion --
WARM AND HUMID CONDITIONS WILL PREVAIL EARLY THIS WEEK AHEAD OF AN
APPROACHING COLD FRONT...WHICH WILL MOVE THROUGH THE AREA WEDNESDAY
NIGHT. THE FRONT MAY LINGER ACROSS PORTIONS OF SOUTH CAROLINA BEFORE
DISSIPATING. HIGH PRESSURE WILL BUILD IN FROM THE NORTH WITH A
DRYING TREND TOWARD THE END OF THE WEEK.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 315 PM MONDAY...WIDELY SCATTERED SHOWERS THIS AFTERNOON ARE
ASSOCIATED WITH A WEAK UPPER LEVEL IMPULSE MOVING FROM WEST TO EAST
ACROSS THE FORECAST AREA. OTHER CONVECTION IS FORMING ALONG THE SEA
BREEZE FRONT CLOSE TO THE COAST. NO THUNDER YET...BUT ANTICIPATE
ISOLATED CB ACTIVITY MAY DEVELOP LATER THIS AFTERNOON.

FOR THE REMAINDER OF THE NEAR TERM...BERMUDA HIGH PRESSURE OFFSHORE
WILL RETREAT TO THE EAST AS A COLD FRONT DROPS DOWN FROM THE NW.
FRONT WILL NOT BE A PLAYER IN THE NEAR TERM...BUT A PERSISTENT
THERMAL TROUGH OVER THE CAROLINA PIEDMONT WILL BE A FOCUS FOR
CONVECTION THIS AFTERNOON. THE SEA BREEZE BOUNDARY WILL BE ANOTHER
MAIN FOCUS FOR CONVECTION. IN ADDITION...A SERIES OF WEAK UPPER
LEVEL IMPULSES AND OLD OUTFLOW BOUNDARIES MOVING FROM WEST TO EAST
ACROSS THE EASTERN CAROLINAS WILL SPARK CONVECTION THIS AFTERNOON
AND OVERNIGHT. ANALYSIS OF MORNING SOUNDING DATA SHOWS A MARGINALLY
UNSTABLE ATMOSPHERE WITH P/W VALUES APPROACHING 2 INCHES...SO EXPECT
PLENTY OF OPPORTUNITY FOR SHOWERS TO FORM AS DISTURBANCES AND
BOUNDARIES MOVE ACROSS THE AREA. AN INVERSION UP AROUND 750MB HAS
KEPT A LID ON ANY STRONG CONVECTION...BUT MODEL SOUNDINGS SHOW THIS
INVERSION WILL ERODE LATER THIS AFTERNOON. STILL DO NOT EXPECT ANY
SEVERE CONVECTION THOUGH.

EXTENSIVE CLOUD COVER AND MODEST WARM SWLY FLOW WILL KEEP OVERNIGHT
TEMPERATURES A BIT ABOVE NORMAL...WITH LOWER 70S INLAND AND MID 70S
AT THE COAST FOR MINIMUMS.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
-- Changed Discussion --
AS OF 315 PM MONDAY...MOISTURE WILL BE ON THE INCREASE TUESDAY WITH
THE MAIN STEERING FROM THE WEST. PRECIPITABLE WATERS WILL PEAK ABOVE
2 INCHES AT TIMES SO THERE IS PLENTY OF MOISTURE TO WORK WITH. THERE
WILL BE HARD TO TIME IMPULSES EMBEDDED IN THE WESTERLY FLOW AS WELL
AS AN APPROACHING COLD FRONT SUPPORTING GOOD CHANCES FOR SHOWERS AND
TSTMS THROUGH MUCH OF THE PERIOD. EXPECT CLOUD COVER WILL LIMIT
HEATING/DESTABILIZATION. THUS ONLY MARGINAL INSTABILITY WILL BE
AVAILABLE WITH NO SEVERE TSTMS EXPECTED. OTHERWISE...AVERAGE
RAINFALL TOTALS ACROSS THE AREA COULD AVERAGE 1-2 INCHES. MAX TEMPS
WILL BE AT OR JUST BELOW CLIMO EACH DAY WITH THE CLOUD COVER HOLDING
TEMPS BACK A BIT. THE WIND WILL BEGIN TO VEER TO A NORTHERLY
DIRECTION WEDNEDAY NIGHT IN THE WAKE OF THE FRONT FROM A
PREDOMINANTLY SOUTHWEST DIRECTION LEADING UP TO ITS PASSAGE.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
AS OF 315 PM MONDAY...HIGH PRESSURE WILL BUILD DOWN FROM THE
NORTHEAST BEHIND COLD FRONT MAKING ITS WAY FARTHER SOUTH. THIS HIGH
OVER THE NORTHEAST ON THURS WILL MOVE EAST SHIFTING OFF THE COAST OF
NEW ENGLAND AND FURTHER OFF SHORE INTO THE ATLANTIC THROUGH THE
PERIOD BUT WILL CONTINUE TO RIDGE DOWN INTO THE CAROLINAS THROUGH
MONDAY. AS THE CENTER OF THE HIGH SHIFTS EAST THE WINDS WILL SHIFT
FROM NORTHEAST ON THURS TO EAST AND THEN SOUTHEAST THROUGH THE
WEEKEND AND SOUTHERLY BY SUNDAY NIGHT INTO MONDAY. AS THE WIND
SHIFTS AROUND TO THE SOUTHEAST SOME LINGERING MOISTURE FROM OLD
FRONTAL BOUNDARY WILL SHIFT BACK NORTH INTO OUR AREA...MAINLY
AFFECTING NORTHEAST SOUTH CAROLINA. THE LINGERING BOUNDARY WILL
WEAKEN AS IT SHIFTS BACK NORTH AND THEREFORE THERE IS SOME
UNCERTAINTY AS TO HOW MUCH OF AN EFFECT IT WILL HAVE ON CONVECTIVE
DEVELOPMENT BY THE END OF THE WEEKEND. THERE IS ALSO SOME
UNCERTAINTY AS TO HOW FAR SOUTH THE FRONT WILL GO AND THEREFORE MAY
KEEP SLIGHT POPS IN FORECAST OVER COAST AND MAINLY SOUTH CAROLINA
THROUGH THE PERIOD. IN THE MID TO UPPER LEVELS...A RIDGE WILL BUILD
UP THE EAST COAST FROM THE GULF OF MEXICO. PCP WATER VALUES DROP TO
LESS THAN AN INCH BY FRI AS THE DRY HIGH PRESSURE NOSES IN FROM THE
NORTHEAST. THERE WILL BE A TIGHT GRADIENT BETWEEN VERY DRY AIR TO
THE NORTH AND MOIST AIR TO THE SOUTH WHERE BOUNDARY REMAINS. PCP
WATER VALUES SOUTH OF THE BOUNDARY OVER THE SOUTHERN HALF OF SOUTH
CAROLINAS WILL BE CLOSER TO 1.9 INCHES. AS MENTIONED PREVIOUSLY THIS
MOISTURE WILL CREEP BACK UP INTO OUR LOCAL CWA MAINLY INTO SOUTH
CAROLINA OVER THE WEEKEND INCREASING THE CHC OF SHOWERS. ALTHOUGH
THE FORECAST REMAIN FAIRLY DRY FOR THE MOST PART...THE MOISTURE
PROFILES DO SHOW A GOOD DEAL OF UPPER LEVEL MOISTURE AND THEREFORE
MAY SEE HIGH CLOUDS STREAMING OVER THE AREA FILTERING OUT THE
SUNSHINE AT TIMES.

AS FOR TEMPS...EXPECT READINGS CLOSE TO CLIMO WITH SLIGHTLY BELOW IN
COOLER NORTHEAST FLOW EARLY IN THE PERIOD AND WARMER TEMPS IN
SOUTHERLY FLOW INTO EARLY NEXT WEEK. 850 TEMPS REMAIN FAIRLY STEADY
RIGHT AROUND 15 C WITH A SLIGHT SPIKE UP ON SATURDAY. HIGH CLOUDS
AND ANY CONVECTIVE DEVELOPMENT MAY AFFECT THE TEMPS AT TIMES BUT
OVERALL EXPECT MAX TEMPS EACH DAY REACHING THE MID 80S AND CLOSER TO
90 INLAND BY THE END OF THE WEEKEND. OVERNIGHT LOWS WILL BE IN THE
60S MOST NIGHTS AND AROUND 70 CLOSER TO THE COAST.
-- End Changed Discussion --

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...AN UPPER IMPULSE IS CURRENTLY MOVING THROUGH THE KFLO
TERMINAL AND SHOULD MOVE THROUGH THE KLBT TERMINAL OVER THE NEXT
HOUR. THIS IMPULSE WILL MOVE TO THE COASTAL TERMINALS BY MID
AFTERNOON. VCSH IS MOST LIKELY WITH THE CONFIDENCE OF THUNDERSTORMS
LOW.

A STRONGER IMPULSE WITH APPROACH THE KFLO/KLBT TERMINALS BY LATE
AFTERNOON...MOVING THROUGH THE COASTAL TERMINALS IN THE EVENING.
CONFIDENCE IS HIGHER SHOWERS/TEMPO THUNDERSTORMS WILL OCCUR WITH
THIS FEATURE. PREDOMINATE VFR SHOULD CONTINUE EXCEPT FOR TEMPO
MVFR/IFR IN THE HEAVIEST SHOWERS.

SHOULD THEN BE A LULL IN CONVECTION AS PATCHY FOG DEVELOPS MAINLY AT
INLAND TERMINALS BY MIDNIGHT REDUCING VSBYS TO MVFR/POTENTIALLY IFR.
CONVECTION WILL DEVELOP AGAIN IN THE PRE-DAWN HOURS CONTINUING
UNTIL THE END OF THE TAF VALID PERIOD.

EXTENDED OUTLOOK...SHOWERS AND THUNDERSTORMS INCREASINGLY LIKELY
TUESDAY THROUGH WEDNESDAY WITH MVFR/TEMPO IFR POSSIBLE. VFR THURSDAY
AND FRIDAY.

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM MONDAY...A STEADY SOUTHWESTERLY FLOW WILL CONTINUE
AROUND THE BACKSIDE OF THE BERMUDA HIGH OVER THE WESTERN ATLANTIC.
EXPECT NOT MUCH CHANGE FROM PRESENT CONDITIONS...WITH WINDS IN THE
15 KT RANGE THROUGH THE PERIOD...AND SEAS OF 3 TO 4 FT.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 315 PM MONDAY...SOUTHWESTERLY FLOW WILL PREVAIL THROUGH MUCH
OF THE SHORT TERM PERIOD AND THE PRESSURE GRADIENT WILL TIGHTEN
AHEAD OF A COLD FRONT ON TAP TO PASS ACROSS THE WATERS WEDNESDAY
NIGHT. THE FLOW WILL VEER TO A NORTHERLY DIRECTION IN THE WAKE OF
THE FRONT WITH SPEEDS AROUND 10 KT. SEAS WILL BUILD TO NEAR SMALL
CRAFT THRESHOLDS ACROSS THE OUTER WATERS DURING WEDNESDAY.
CONFIDENCE IS LOW AT THIS POINT THUS NO PLAN TO RAISE AN ADVISORY
THIS EARLY.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 315 PM MONDAY...AS MENTIONED PREVIOUSLY...HIGH PRESSURE
RIDGING DOWN FROM THE NORTH TO NORTHEAST THROUGH THE PERIOD WILL
FIGHT TO KEEP A FRONT TO THE SOUTH. OVERALL EXPECT STIFF NORTHEAST
WINDS BEHIND FRONT ON THURS TO WEAKEN AND VEER AROUND TO THE EAST
THROUGH SATURDAY AS HIGH SHIFTS FURTHER OFF THE NEW ENGLAND COAST
AND EVENTUALLY SETTLES OVER BERMUDA. WINDS WILL BE CLOSER TO 4 TO 5
FT IN OUTER WATERS THURS IN NE WINDS CLOSER TO 15 KTS. NEAR SHORE
SEAS SOUTH OF CAPE FEAR WILL BE BLOCKED FROM NORTHEAST WINDS AND
WILL BE LOWER...CLOSER TO 1 TO 2 FT. AS WINDS VEER AROUND AND
LIGHTEN HEADING INTO THE WEEKEND THE SEAS WILL SUBSIDE TO 1 TO 3 FT
MOST WATERS AND WILL REMAIN LOW THROUGH MOST OF THE WEEKEND AS LIGHT
WINDS 10 KTS OR SO CONTINUE TO SHIFT AROUND TO THE SOUTHEAST.
-- End Changed Discussion --

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...REK
SHORT TERM...SRP
LONG TERM...RGZ
AVIATION...MRR/REK