000
FXUS62 KGSP 151845
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
245 PM EDT WED MAY 15 2013

.SYNOPSIS...
HIGH PRESSURE SITUATED OFF THE CAROLINA COAST WILL DRIVE
SOUTHWESTERLY FLOW FOR THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA... MAINTAINING A WARM AND MOIST AIRMASS THROUGHOUT THE
PERIOD. AN UPPER LEVEL DISTURBANCE WILL APPROACH ON THURSDAY AND
KEEP THE PATTERN UNSETTLED THROUGH EARLY NEXT WEEK... WITH A COLD
FRONT EXPECTED TO CROSS THE REGION BY LATE TUESDAY OR EARLY
WEDNESDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 230 PM EDT...PLEASANT WEATHER CONDITIONS CONTINUE TO PREVAIL
ACROSS THE WESTERN CAROLINAS AND NORTHEAST GEORGIA.  AMPLE SUNSHINE
AND SOUTH TO SOUTHWESTERLY FLOW AT THE SFC HAS PROPELLED
TEMPERATURES WELL INTO THE LOWER TO MID 80S WITH SOME SITES
REPORTING IN THE UPPER 80S.

OTHERWISE...UPPER LEVEL RIDGE CONTINUES TO DOMINATE THE WEATHER
ACROSS THE ENTIRE SOUTHEASTERN UNITED STATES.  A RATHER LOW
AMPLITUDE LONG WAVE TROUGH...AND AN ASSOCIATED CUTOFF 570MB LOW WERE
LOCATED OVER WESTERN OKLAHOMA AND PORTIONS OF WEST TEXAS.  WATER
VAPOR IMAGERY SHOWS A PLUME OF MOISTURE SPILLING IN ON THE EAST SIDE
OF THIS FEATURE ACROSS THE MIDSOUTH ALLOWING FOR SOME THUNDERSTORM
DEVELOPMENT.  LOCALLY...THE ABOVE MENTIONED RIDGE LOOKS TO BREAK
DOWN OVER THE NEXT 24 HOURS AS THE WHOLE PATTERN SHIFTS EASTWARD.
LOOKING AT MODEL GUIDANCE...BOTH THE NAM AND THE GFS SHOW A
DEVELOPING MCS FEATURE OVER PORTIONS OF THE OHIO VALLEY DURING THE
MID TO LATE MORNING HOURS ON THURSDAY.  AS THIS FEATURE CONTINUES TO
MOVE DOWNSTREAM IN THE NORTHWEST FLOW ALOFT...THE ATMOSPHERE WILL
CONTINUE TO DESTABILIZE OVER THE NORTH CAROLINA MOUNTAINS AND BOTH
THE SOUTH AND NORTH CAROLINA FOOTHILLS.  AS THE MCS...OR ITS
REMNANTS APPROACH THE MOUNTAINS BY EARLY AFTERNOON...CONVECTION WILL
LIKELY INCREASE IN COVERAGE.  FURTHERMORE...BY MID TO LATE
AFTERNOON...THERE IS A CHANCE THAT SHOWERS AND THUNDERSTORMS WILL
DEVELOP OVER THE PIEDMONT REGIONS OF NORTH AND SOUTH CAROLINA AS
THESE PROCESSES PROGRESS TO THE SOUTHEAST.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...THE SHORT TERM WILL FEATURE DIURNALLY
DRIVEN CONVECTION ALONG WITH A WEAK ZONAL UPPER FLOW THROUGH SAT.
THE MODELS FORECAST A COUPLE WEAK IMPULSES MOVING ACROSS THE AREA AS
WELL. ANY REMNANT CONVECTION THU EVENING SHOULD DISSIPATE BEFORE
MIDNIGHT WITH PARTLY CLOUDY AND MILD CONDITIONS PREVAILING FOR THE
OVERNIGHT. PARTLY CLOUDY CONDITIONS SHOULD THEN PREVAIL THROUGH
FRIDAY...WITH SCATTERED SHOWERS/THUNDERSTORMS DEVELOPING OVER THE
MOUNTAINS BY EARLY AFTERNOON...AND IN THE FOOTHILLS AND PIEDMONT
AREAS DURING THE MID TO LATE AFTERNOON HOURS. CONVECTION SHOULD WANE
AGAIN FRI NIGHT...THEN SCATTERED SHOWERS/STORMS SHOULD FIRE BACK UP
SAT AFTERNOON ACROSS THE FORECAST AREA. WARM LOW LEVEL THICKNESS
VALUES WILL SUPPORT ABOVE AVERAGE TEMPS ON FRI AND SAT. USED A BLEND
OF GUIDANCE SOURCES TO GENERATE TEMP FIELDS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 140 PM WEDNESDAY...WPC FAVORED A BLEND OF THE 06Z GFS/00Z ECM
ENSEMBLES FOR THE MEDIUM RANGE. THE EXPECTATION IS FOR AN AMPLIFYING
UPPER RIDGE TO DEVELOP OVER THE EASTERN U.S. THE FIRST PART OF NEXT
WEEK AS A SIGNIFICANT UPPER TROUGH DEVELOPS OVER THE CENTRAL PART OF
THE COUNTRY. THE WEEKEND LOOKS LIKE IT WILL BE QUITE UNSETTLED AS A
REMNANT VORT MAX MOVES ACROSS THE AREA SAT NIGHT INTO SUNDAY...AND A
BACKDOOR COLD FRONT APPROACHES. THE LATEST GUIDANCE DOES KEEP THE
FRONT JUST TO THE NE OF THE AREA SAT NIGHT INTO SUN. HENCE...WILL
HAVE FAIRLY ROBUST POPS IN THE SAT NIGHT/SUN TIMEFRAME WITH THE
HIGHEST VALUES OVER THE NORTHERN REACHES OF THE FORECAST AREA. AS
THE UPPER RIDGE BUILDS NEXT WEEK...THE PRECIP SHOULD BECOME MORE
DIURNAL IN NATURE WITH THE HIGHEST COVERAGE OF SHOWERS/STORMS OVER
THE CLIMATOLOGICAL FAVORED MOUNTAINS. WITH MORE IN THE WAY OF
CLOUDINESS EXPECTED...MAX TEMPS SHOULD AVERAGE NEAR NORMAL SUN AND
MON...BUT RISE TO ABOUT A CATEGORY ABOVE AVERAGE FOR TUE AND WED.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...VFR CONDITIONS WILL CONTINUE TO PREVAIL
THROUGH THE ENTIRE TAF PERIOD.  SOUTHWEST WINDS WILL DECREASE IN
MAGNITUDE DURING THE OVERNIGHT HOURS TONIGHT...BEFORE INCREASING YET
AGAIN BY LATE MORNING ON THURSDAY.  MODEL GUIDANCE CONTINUES TO
INDICATE SOME INSTABILITY ACROSS THE ENTIRE REGION...MAINLY AFTER
18Z THURSDAY SO THUNDERSTORMS ARE NOT EXPECTED BEFORE THE END OF THE
TAF PERIOD.

OUTLOOK...VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE REST OF
THE WEEK. HOWEVER...SCATTERED AFTN AND EVENING THUNDERSTORMS WILL BE
POSSIBLE FROM THURSDAY AFTERNOON THROUGH THE WEEKEND.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...LEV
NEAR TERM...CDG/PM
SHORT TERM...LG
LONG TERM...LG
AVIATION...CDG/PM