Area Forecast Discussion
Issued by NWS Charleston, SC

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824
FXUS62 KCHS 221453
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1053 AM EDT FRI MAY 22 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...GRADUALLY
SHIFTING INTO THE WESTERN ATLANTIC. IT WILL REMAIN THE DOMINANT
WEATHER FEATURE THROUGH LATE NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATE THIS MORNING...NO CHANGE TO THE FORECAST THINKING FOR THE
REST OF THE DAY. COOLER AND DRIER HIGH PRESSURE CENTERED OVER THE
MID MISSISSIPPI VALLEY CONTINUES TO BRIDGE ACROSS THE APPALACHIANS
AND BUILD INTO THE REGION. THE LEADING EDGE OF THE MAIN
NORTHEASTERLY SURGE AND AIRMASS CHANGE HAS NOW PUSHED FAR ENOUGH
SOUTH TO REACH SAVANNAH AND WILL REACH THE ALTAMAHA IN THE NEXT
FEW HOURS. WE WILL LIKELY CONTINUE TO SEE PARTLY TO MOSTLY CLOUDY
SKIES INTO THE AFTERNOON UNTIL WE CAN GET ENOUGH SURFACE HEATING
TO HELP SCATTER IT OUT. HIGHS WILL BE MUCH COOLER THAN
YESTERDAY...WITH HIGHS TOPPING OUT IN THE UPPER 70S TO AROUND 80
ACROSS SOUTHEAST SOUTH CAROLINA...AND LOW 80S FOR SOUTHEAST
GEORGIA.

TONIGHT...MUCH COOLER CONDITIONS AS WINDS DECOUPLE AWAY FROM THE
BEACHES AND BARRIER ISLAND AND LOWS FALL INTO THE MID/UPPER 50S
INLAND UNDER CLEAR SKIES. MANY COASTAL AREAS EAST OF U.S. 17 WILL
FALL TO AROUND 60 WITH MILDER CONDITIONS RIGHT AT THE LAND/SEA
INTERFACE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
UNSEASONABLY DRY HIGH PRESSURE WILL SETTLE OVER THE AREA FROM THE
NORTH SATURDAY WHILE AN UPPER RIDGE STRENGTHENS OVERHEAD. THE
SURFACE HIGH WILL SHIFT INTO THE WESTERN ATLANTIC SUNDAY INTO MONDAY
THOUGH THE UPPER RIDGE WILL CONTINUE TO BUILD. WE WILL BE HARD
PRESSED TO INITIATE ANY CONVECTION SATURDAY OR SUNDAY GIVEN SUCH
MEAGER MOISTURE PROFILES AND STRONG CAPPING. WE INCLUDED A SLIGHT
CHANCE POP ACROSS FAR SOUTHWESTERN ZONES ON MONDAY WHERE PWATS
INCREASE TO AROUND 1.6" AND AFTERNOON TEMPS RISE INTO THE UPPER 80S.
COVERAGE SHOULD STILL BE QUITE LIMITED DUE TO SUCH WARM MID-LEVELS.
TEMPS WILL SHOW A WARMING TREND DURING THE PERIOD.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A STRONG DEEP LAYERED RIDGE WILL REMAIN THE DOMINANT WEATHER FEATURE
DURING THE LONG TERM PERIOD. INCREASING LOW-LEVEL THICKNESSES
SUPPORT A WARMING TREND WITH TEMPS SEVERAL DEGREES ABOVE NORMAL
THROUGH THE PERIOD. A STRONG MID-LEVEL CAP WILL MINIMIZE RAIN
CHANCES THROUGH WEDNESDAY. SOME SHORTWAVE ENERGY WILL BEGIN TO ERODE
THE RIDGE FROM THE WEST THURSDAY INTO FRIDAY...POTENTIALLY ALLOWING
FOR ISOLATED SHOWERS AND TSTMS TO MOVE INTO INLAND AREAS DURING THE
AFTERNOON HOURS.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AT KSAV...AN AREA OF MVFR LEVEL STRATOCUMULUS HAS DEVELOPED IN THE
LAST HOUR OR SO. THIS WILL PERSIST AS THE PREVAILING CONDITION
THROUGH ABOUT NOON...THEN WILL BEGIN TO LIFT AND SCATTER OUT
THEREAFTER. OTHERWISE...VFR CONDITIONS WILL PREVAIL WITH SOME
GUSTY NORTHEAST WINDS AT TIMES.

EXTENDED AVIATION OUTLOOK...MAINLY VFR.

&&

.MARINE...
THE NORTHEAST SURGE CONTINUES TO WORK ITS WAY DOWN THE COAST
ACROSS THE LOCAL WATERS THIS MORNING. THE SURGE HAS BEEN A BIT
STRONGER THAN EXPECTED...WITH SOME GUSTS INTO THE 25-27 KT RANGE
ACROSS THE NEARSHORE WATERS AT TIMES. THE STRONGEST WINDS APPEAR
TO BE ASSOCIATED WITH THE LEADING EDGE...AND THE GEORGIA WATERS
WILL LIKELY EXPERIENCE THIS STRONG PUNCH IN THE NEXT COUPLE OF
HOURS. IT STILL APPEARS THAT THE STRONGEST NORTHEAST WINDS ARE
RELATIVELY SHORT-LIVED...ON THE ORDER OF 2 HOURS...AND NO SMALL
CRAFT ADVISORIES WILL BE RAISED. INSTEAD...HAVE GONE WITH A SOLID
20 KT FOR MUCH OF THE DAY ACROSS ALL ZONES OTHER THAN THE
CHARLESTON HARBOR. GUSTS TO AROUND 25 KT WILL BE POSSIBLE THROUGH
THE EARLY AFTERNOON. CHOPPY CONDITIONS WILL EXIST WITH SEAS UP TO
4 OUT TO 20 NM...AND UP TO 5 FT BEYOND INTO THE OUTER GEORGIA
WATERS.

TONIGHT...THE TIGHTER GRADIENT WILL RESIDE OVER SOUTHERN GEORGIA
WATERS AND WITH A BETTER FETCH GEORGIA WATERS...SEAS SHOULD WAVER
FROM 4-5 FT OVER GEORGIA WATERS BEYOND 20 NM.

A LONG EAST-NORTHEAST FETCH WITH SLIGHTLY ENHANCED GRADIENT WILL
EXIST SATURDAY AND SUNDAY AS HIGH PRESSURE SHIFTS EAST FROM THE MID-
ATLANTIC REGION. WITH THE PREVAILING ONSHORE FLOW AND WARM LAND
TEMPS WE EXPECT A ROBUST AFTERNOON SEA BREEZE BOTH DAYS.
ADDITIONALLY...SEAS WILL GRADUALLY BUILD AND WE COULD SEE 6 FT SEAS
OVER OUTER PORTIONS OF THE OFFSHORE GA WATERS SATURDAY NIGHT THROUGH
SUNDAY. OTHERWISE...CONDITIONS WILL REMAIN BELOW ADVISORY LEVELS
THROUGH LATE NEXT WEEK.

&&

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

&&

$$

NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...BSH
MARINE...BSH/JRL



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