Area Forecast Discussion
Issued by NWS Charleston, SC

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FXUS62 KCHS 011137
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
737 AM EDT WED JUL 1 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL RESIDE ACROSS THE AREA WHILE A TROUGH
OF LOW PRESSURE PERSISTS INLAND.

&&

.NEAR TERM /THROUGH TONIGHT/...
A RELATIVELY ZONAL FLOW WILL EXIST TODAY BEHIND A DEPARTING
SHORTWAVE. THIS DEEP WESTERLY FLOW WILL PRODUCE BROAD SUBSIDENCE
AND MAINTAIN A DRIER COLUMN FOR AT LEAST THE FIRST PART OF THE
DAY. FAIRLY UNSEASONABLE PWATS BELOW 1.5" WILL SUPPORT MOSTLY
SUNNY SKIES THIS MORNING AND LITTLE TO NO PRECIPITATION. LATER IN
THE AFTERNOON A SHORTWAVE WILL DROP INTO GA/SC FROM THE NW. LOW
AND MID LEVEL FLOW WILL BACK IN ADVANCE OF THE WAVE...PRODUCING
SOMEWHAT MORE FAVORABLE CONDITIONS FOR SURFACE-BASED CONVECTION.
EVEN SO...THE SEA BREEZE WILL REMAIN PINNED NEAR THE COAST BY THE
WESTERLY FLOW. THUS ANY CONVECTION WOULD LIKELY BE LATE IN THE
AFTERNOON OR EARLY THIS EVENING ONCE THE SHORTWAVE GETS CLOSER TO
THE AREA AND POTENTIALLY INTERACTS WITH THE SEA BREEZE. HIGH
TEMPERATURES ARE EXPECTED TO REACH THE LOW TO MIDDLE 90S WITH
LITTLE RELIEF ALONG THE IMMEDIATE COAST UNTIL LATE DAY WHEN THE
SEA BREEZE CREEPS INLAND. WE KEPT POPS FAIRLY LOW TODAY...MAINLY
20 TO 30 PERCENT WITH HIGHEST VALUES ACROSS SOUTHEAST GA AND THE
COASTAL WATERS.

DUE TO THE SHORTWAVE IN THE PROXIMITY THIS EVENING...SOME
CONVECTION COULD LINGER AFTER DARK. HOWEVER WITH THE LOSS OF
DAYTIME HEATING...THE BOUNDARY LAYER SHOULD STABILIZE RELATIVELY
QUICKLY AND BRING PRECIPITATION TO AN END OVER LAND AREAS. SOME
SHOWERS OR THUNDERSTORMS COULD LINGER OVER THE COASTAL WATERS
HOWEVER. LOWS WILL BE IN THE LOWER 70S.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY AND THURSDAY NIGHT...THE REGION WILL BE POSITIONED ALONG
THE EASTERN PERIPHERY OF A BROAD UPPER LEVEL TROUGH WHILE AT THE
SURFACE A PIEDMONT TROUGH WILL BE LOCATED NORTHWEST OF THE AREA AS
HIGH PRESSURE BUILDS IN FROM THE WESTERN ATLANTIC. DEEPENING
MOISTURE PROFILES DUE TO A SOUTHWEST FLOW COMBINED WITH A
DISTURBANCE ROUNDING THE BASE OF THE UPPER TROUGH WILL SUPPORT A
GOOD CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA...MAINLY
DURING THE MID-AFTERNOON TO EARLY EVENING. THERE IS THE POTENTIAL
FOR A FEW OF THE STORMS TO BECOME SEVERE...AS IT APPEARS THAT SOME
ORGANIZED CONVECTION COULD TRANSLATE INTO THE AREA AHEAD OF THE
UPPER DISTURBANCE. THE PRIMARY THREAT APPEARS TO BE DAMAGING WIND
GUSTS AND MENTION WILL BE ADDED TO THE HAZARDOUS WEATHER OUTLOOK.
HIGHS WILL GENERALLY BE IN THE LOWER 90S WITH LOWS IN THE LOWER TO
MID 70S INLAND FROM THE IMMEDIATE COAST.

FRIDAY AND FRIDAY NIGHT...A LACK OF STRONG FORCING FOR ASCENT WILL
LIMIT THE COVERAGE OF SHOWERS AND THUNDERSTORMS...BUT CONTINUED DEEP
MOISTURE PROFILES...THE SEA BREEZE AND THE NEARBY PROXIMITY OF THE
PIEDMONT TROUGH WILL STILL SUPPORT ISOLATED TO SCATTERED CONVECTION
ACROSS THE AREA. THE BEST COVERAGE SHOULD BE UP IN THE CHARLESTON
TRI-COUNTY AREA. WHILE CONVECTION WILL BE MOST LIKELY DURING THE
AFTERNOON AND EARLY EVENING...CANNOT RULE OUT ISOLATED COVERAGE
PERSISTING WELL INTO THE NIGHT...WITH A GREATER FOCUS OVER THE
ADJACENT COASTAL WATERS.  TEMPERATURES SHOULD WARM INTO THE LOWER TO
MID 90S FOR HIGHS...WITH LOWS IN THE LOWER TO MID 70S.

SATURDAY...THE SEA BREEZE APPEARS TO BE THE PRIMARY FOCUS FOR ANY
CONVECTION...WITH THE STRONGEST LOW LEVEL CONVERGENCE EXPECTED
ACROSS THE CHARLESTON TRI-COUNTY AREA WHERE SCATTERED SHOWERS AND
THUNDERSTORMS ARE FORECAST DURING THE AFTERNOON AND EARLY EVENING.
ELSEWHERE...CONVECTION APPEARS TO BE ISOLATED IN COVERAGE AT BEST.
HIGHS WILL BE IN THE LOWER 90S FOR MOST AREAS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE END OF THE WEEKEND WILL CONTINUE TO FEATURE AN INLAND TROUGH AS
HIGH PRESSURE CONTINUES TO BUILD IN FROM THE ATLANTIC. COVERAGE OF
SHOWERS AND THUNDERSTORMS SHOULD BE RATHER MINIMAL ON SUNDAY WITH
LITTLE IN THE WAY OF STRONG FORCING FOR ASCENT. BY EARLY NEXT
WEEK...MODELS ARE TRENDING A BIT WETTER AS THEY INDICATE MORE IN THE
WAY OF TROUGHING ALOFT. THIS WILL NOT ONLY SUPPORT AT LEAST
SCATTERED SHOWERS AND THUNDERSTORMS EACH DAY...BUT COULD ALSO RESULT
IN SLIGHTLY COOLER TEMPERATURES THAN WHAT IS CURRENTLY FORECAST.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV THROUGH 12Z THURSDAY.
THE POTENTIAL FOR TSTMS APPEARS FAIRLY LOW TODAY THOUGH THE BEST
CHANCE WOULD BE LATE AFTERNOON OR EARLY EVENING ACROSS KSAV.

EXTENDED AVIATION OUTLOOK...BRIEF FLIGHT RESTRICTIONS ARE POSSIBLE
IN MAINLY AFTERNOON/EARLY EVENING ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS. OTHERWISE...VFR CONDITIONS ARE GENERALLY EXPECTED TO
PREVAIL.

&&

.MARINE...
THROUGH MONDAY...ATLANTIC HIGH PRESSURE WILL GENERALLY DOMINATE
THE WEATHER PATTERN OVER THE COASTAL WATERS WITH A PIEDMONT TROUGH
SITUATED INLAND. A TIGHTENED PRESSURE GRADIENT BETWEEN THE TWO
FEATURES WILL KEEP WINDS FAIRLY ELEVATED THROUGH THE PERIOD. IN
FACT...IT APPEARS THAT CONDITIONS COULD REACH MARGINAL SMALL CRAFT
ADVISORY CRITERIA OVER A PORTION OF THE WATERS FRIDAY AFTERNOON
INTO FRIDAY NIGHT. OTHERWISE...SEA BREEZE CIRCULATIONS AND
NOCTURNAL LOW LEVEL JETTING WILL ALLOW SOUTH/SOUTHWEST WINDS TO
PEAK NEAR 15-20 KTS...WITH 25 KTS LOCALLY AT TIMES IN FAVORED
LOCATIONS. SEAS WILL BE 2-4 FEET ON AVERAGE...BUT COULD REACH 5 FT
IN THE OUTER PORTIONS OF THE WATERS DURING NOCTURNAL SURGES.

&&

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

&&

$$

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



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