-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCHS 141058
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
658 AM EDT FRI JUN 14 2013

.SYNOPSIS...
A COLD FRONT WILL DROP THROUGH THE AREA EARLY THIS MORNING. HIGH
PRESSURE WILL BUILD OVER THE WEEKEND AND PERSIST INTO EARLY NEXT
WEEK. A COLD FRONT WILL APPROACH FROM THE NORTHWEST BY THE MIDDLE
OF NEXT WEEK AND POSSIBLY STALL OVER THE REGION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
THE COLD FRONT IS MOVING STEADILY SOUTH AND WILL CLEAR THE
ALTAMAHA RIVER IN A FEW MORE HOURS. AREAS ALONG AND SOUTH OF THE
FRONT WILL HAVE THE BEST CHANCES FOR ANY SHOWERS/TSTM ACTIVITY
BEFORE THE BOUNDARY CLEARS THE FORECAST AREA. WILL CARRY 20-30
PERCENT POPS TO HOLD...ALTHOUGH THE REMNANT CAPPING INVERSION
NOTED ON THE 14/00Z CHS RAOB WILL LIKELY PREVENT TOO MUCH
CONVECTION FROM FIRING. DRIER AIR WILL ADVECT IN FROM THEN NORTH
WITH DEWPOINTS STEADILY DROPPING THROUGHOUT THE DAY. IT WILL BE
NOTICEABLY LESS HOT AND HUMID AS A RESULT WITH HIGHS ONLY RISING
INTO THE UPPER 80S/AROUND 90 COMPARED TO MID-UPPER 90S THAT HAVE
BEEN COMMON OVER THE PAST SEVERAL DAYS. SKIES WILL GRADUALLY CLEAR
WITH MOSTLY SUNNY TO PARTLY CLOUDY SKIES DOMINATING AS WINDS TIP
FROM NORTHWEST...TO NORTH AND EVENTUALLY NORTHEAST.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
TONIGHT...HIGH PRESSURE WILL BUILD STEADILY SOUTH INTO THE AREA
TONIGHT AS UPPER RIDGING TAKES HOLD ALOFT. CLEAR SKIES...LIGHT
WINDS AND FAIRLY LOW DEWPOINTS WILL PROMOTE MODEST RADIATIONAL
CONDITIONS YIELDING SOME FAIRLY COOL LOWS COMPARED TO WHAT HAS
BEEN OBSERVED OF LATE. LOWS WILL RANGE FROM THE LOWER 60S WELL
INLAND TO THE LOWER 70S AT THE BEACHES WHERE INFLUENCES FROM THE
WARMER ATLANTIC WATERS AND WEAK ONSHORE FLOW WILL HELP KEEP
TEMPERATURES SOMEWHAT ELEVATED.

SATURDAY AND SUNDAY...SURFACE HIGH PRESSURE WILL STEADILY DESCEND
INTO THE REGION FROM THE NORTHWEST AND SETTLE INTO THE ATLANTIC OVER
THE WEEKEND...WHILE UPPER LEVEL RIDGING BUILDS INTO THE SOUTHEAST
STATES. THIS PATTERN WILL SUPPORT LARGE SCALE SUBSIDENCE THAT WILL
EFFECTIVELY SUPPRESS CONVECTIVE DEVELOPMENT SATURDAY AND SUNDAY
ACROSS THE FORECAST AREA. HAVE THUS INDICATED ZERO RAIN CHANCES BOTH
DAYS UNDER MOSTLY CLEAR TO PARTLY CLOUDY SKIES. THICKNESS VALUES
AGREE FAIRLY WELL WITH MODEL GUIDANCE REGARDING HIGH
TEMPERATURES...AND EXPECT TEMPERATURES TO PEAK IN THE UPPER 80S TO
AROUND 90 DEGREES AWAY FROM THE LOCALLY COOLER COASTLINE.

MONDAY...HIGH PRESSURE AT THE SURFACE AND ALOFT WILL BEGIN TO
RETREAT AS THE DAY PROGRESSES...AHEAD OF SHORTWAVE ENERGY AND AN
ASSOCIATED SURFACE TROUGH APPROACHING FROM THE WEST. WILL
REINTRODUCE A SLIGHT CHANCE OF THUNDERSTORMS MAINLY ACROSS INLAND
AREAS...DUE TO UPSTREAM ACTIVITY POTENTIALLY SLIPPING INTO THE
WESTERN ZONES. THE MAJORITY OF THE FORECAST AREA COULD REMAIN
UNDER RESIDUAL CAPPING DURING THE DAYTIME HOURS. HIGH TEMPERATURES
WILL REACH THE UPPER 80S TO LOWER 90S WITHIN INCREASING WARM
SOUTHERLY FLOW.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE PATTERN WILL BECOME MORE UNSETTLED EARLY NEXT WEEK AND THROUGH
MUCH OF THE EXTENDED FORECAST PERIOD. MEDIUM RANGE FORECAST
MODELS SUGGEST THAT A BROAD UPPER TROUGH DEVELOPING OVER THE EAST
COAST STATES WILL ALLOW A SERIES OF SHORTWAVES TO MOVE THROUGH THE
REGION...SUPPORTING THE EVENTUAL PROGRESSION OF A BACKDOOR COLD
FRONT INTO THE AREA BY THE MIDDLE OF NEXT WEEK. THE FRONT COULD
STALL OVER THE FORECAST AREA AS IT BECOMES MORE PARALLEL TO FLOW
ALOFT WEDNESDAY AND THURSDAY. IF THIS SCENARIO OCCURS...THEN
THUNDERSTORM POTENTIAL WILL INCREASE FROM SLIGHT CHANCE MONDAY
NIGHT AND EARLY TUESDAY INTO PERSISTENT 30 TO 40 PERCENT CHANCES
FROM LATER TUESDAY THROUGH AT LEAST THURSDAY. PREFERRED TO REMAIN
SOMEWHAT GENERIC THIS FAR IN ADVANCE...AND WILL REFINE DETAILS AS
MODEL SOLUTIONS COME INTO BETTER AGREEMENT. HIGH TEMPERATURES WILL
RANGE FROM THE UPPER 80S TO THE LOWER 90S AWAY FROM THE LOCALLY
COOLER COASTLINE EACH AFTERNOON.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR.

EXTENDED AVIATION...NO CONCERNS.

&&

.MARINE...
TODAY...SOUTHWEST WINDS WILL TURN NORTH AND EVENTUALLY NORTHEAST
TODAY IN THE WAKE OF A COLD FRONT. ELEVATED WINDS EARLY THIS
MORNING AHEAD OF THE FRONT WILL SUBSIDE AS THE LOW-LEVEL JET
PUSHES FARTHER EAST INTO THE OPEN ATLANTIC. BOTH WINDS AND SEAS
ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA.

TONIGHT...EAST TO NORTHEAST WINDS WILL DOMINATE THROUGH TONIGHT
WITH BOTH WINDS AND SEAS REMAINING WELL BELOW ADVISORY THRESHOLDS.

SATURDAY THROUGH TUESDAY...BENIGN CONDITIONS ARE EXPECTED OVER
ALL COASTAL WATERS THROUGH THE WEEKEND...AS ATLANTIC HIGH PRESSURE
BUILDS BEHIND A COLD FRONT SHIFTING FAR OUT TO SEA. WINDS WILL
QUICKLY VEER FROM EAST TO SOUTHEAST ON SATURDAY...BECOMING
PREVAILING SOUTH/SOUTHEAST THROUGH EARLY NEXT WEEK. WINDS AND SEAS
WILL THEN STEADILY INCREASE/BUILD OVER ALL WATERS BY LATE
MONDAY...AS THE PRESSURE GRADIENT TIGHTENS BETWEEN LOW PRESSURE
ADVANCING TO THE NORTHEASTERN UNITED STATES AND HIGH PRESSURE OVER
THE WESTERN ATLANTIC. CONDITIONS SHOULD STILL REMAIN BELOW SMALL
CRAFT ADVISORY LEVELS THROUGH THE PERIOD...WITH WINDS PEAKING
BETWEEN 15 TO 20 KT AND SEAS UP TO 4 TO 5 FT...HIGHEST BEYOND 10
NM FROM THE COAST.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST/WMS