Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 262321
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
721 PM EDT TUE AUG 26 2014

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BRING MOSTLY DRY CONDITIONS TO THE
REGION TONIGHT INTO THURSDAY. MOISTURE AND TEMPERATURES WILL
GRADUALLY INCREASE THIS WEEKEND INTO EARLY NEXT WEEK AS A BERMUDA
HIGH PRESSURE REDEVELOPS.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 715 PM EDT TUESDAY...ASIDE FOR LIMITED HIGH LEVEL CIRRUS
STREAMING ALOFT AND PATCHY LOW LEVEL CU ACROSS PORTIONS OF THE
MOUNTAINS...SKIES REMAIN MOSTLY SUNNY.  LATEST GUIDANCE REMAINS IN
LINE WITH THE PREVIOUS FORECAST THEREFORE NO CHANGES WERE MADE.  DID
TWEAK TEMPERATURES AND DEWPOINTS IN THE EXTREME NEAR TERM TO REFLECT
LATEST OBSERVATIONAL TRENDS.

PREVIOUS DISCUSSION...

AT 200 PM EDT TUESDAY...AN UPPER RIDGE FROM THE MID ATLANTIC REGION
TO NORTHERN MEXICO WILL START TO BREAK DOWN OVER THE CAROLINAS ON
WEDNESDAY AS TROPICAL SYSTEM CRISTOBAL MOVES NORTH OFF THE EAST
COAST. DRY SURFACE HIGH PRESSURE OVER THE CAROLINAS AND GA WIL
PERSIST...BUT WEAKEN. DUE TO THE MOTION OF CRISTOBAL...SURFACE
WINDS WILL BACK FORM NE TO N OVERNIGHT...INTRODUCING A LIGHT
DOWNSLOPE FLOW IN A WEAK PRESSURE GRADIENT. MODEL TIME HEIGHTS SHOW
THE LIMITED MOISTURE NOW AROUND 900 MB LARGELY DIMINISHING BY
DAYBREAK. MINIMUM TEMPERATURES TONIGHT WILL RUN AROUND SEVEN DEGREES
BELOW NORMAL...AND MAXIMUM TEMPERATURES ON WEDNESDAY NEAR NORMAL.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS OF 215 PM TUESDAY...DRY HIGH PRESSURE WILL CONTROL THE WEATHER
OVER THE REGION WED NIGHT THROUGH THU MORNING. WITH THE AXIS OF THE
UPPER RIDGE REMAINING WEST OF THE AREA AND STRONG SHORT WAVE ENERGY
MOVING THROUGH NEW ENGLAND ON THU...A BACKDOOR FRONT WILL MAKE A RUN
AT THE AREA. THE 12Z MODEL RUNS  HAVE COME INTO BETTER AGREEMENT
THAT THE BOUNDARY WILL REACH I-40 CORRIDOR INTO SRN VA ON BY LATE
THURSDAY. ALL THE MODELS SHOW SOME QPF RESPONSE IN THE VICINITY OF
THE FRONT AND OVER THE NC MOUNTAINS AS CAPES INCREASE TO PERHAPS
1000J/KG OR MORE. HENCE...WILL CONTINUE WITH THE IDEA THAT WIDELY
SCT/SCT THUNDERSTORMS WILL DEVELOP FROM THE NC MOUNTAINS...EASTWARD
ACROSS AND NORTH OF THE I-40 CORRIDOR. WITH THE LOSS OF DAYTIME
HEATING...EXPECT CONVECTION TO WANE THU EVENING. AS THE UPPER RIDGE
RE-ASSERTS ITSELF ON FRIDAY...DRY CONDITIONS ARE EXPECTED. MAX TEMPS
WILL BE A CATEGORY OR MORE ABOVE NORMAL BOTH THURSDAY AND FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 200 PM TUESDAY...AN UPPER RIDGE WILL REMAIN OVER THE SE U.S.
THROUGH TUE BUT DE-AMPLIFY SOMEWHAT THE FIRST PART OF NEXT WEEK AS
SHORT WAVE ENERGY MOVES THROUGH THE OHIO VALLEY. AT THE SURFACE...
THE BERMUDA HIGH WILL DOMINATE. CURRENT MODEL GUIDANCE SUGGESTS THAT
SATURDAY SHOULD BE GENERALLY DRY ACROSS THE AREA WITH DEEP LAYER
HIGH PRESSURE DOMINATING. THE EXCEPTION MAY BE THE SW NC MOUNTAINS
AND NE GA MOUNTAINS WHERE UPSLOPE FLOW MAY TRIGGER SOME SCT
AFTERNOON CONVECTION. PRECIP CHANCES WILL IMPROVE ON SUNDAY AS
MOISTURE INCREASES AND UPPER HEIGHTS FALL SOMEWHAT. CURRENT GUIDANCE
SUGGESTS NUMEROUS SHOWERS/STORMS FOR THE MOUNTAINS AND SCT ELSEWHERE
ON SUNDAY. WILL ADVERTISE NEAR CLIMO POPS FOR SCT DIURNAL CONVECTION
BOTH MONDAY AND TUE AS THE BERMUDA HIGH REMAINS IN PLACE OVER THE SE
STATES. TEMPS WILL BE ABOUT A CATEGORY OR SO ABOVE AVERAGE THROUGH
THE PERIOD.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD AS HIGH
PRESSURE DOMINATES THE PATTERN.  LIGHT NORTHEASTERLY FLOW WILL
CONTINUE THROUGH THE OVERNIGHT UNDER A FEW HIGH LEVEL CIRRUS.
EXPECTING CLEAR SKIES TOMORROW WITH LIGHT NORTH/NORTHWESTERLY
DOWNSLOPING WINDS AS HURRICANE CRISTOBALS WIND FIELD WORKS TO BACK
LOW LEVEL FLOW ACROSS THE SOUTHEAST AND MIDATLANTIC.

ELSEWHERE...MUCH THE SAME AS KCLT ABOVE WITH VFR PREVAILING THROUGH
THE PERIOD WITH THE EXCEPTION OF LOW LEVEL STRATUS ASSOCIATED WITH
FOG DEVELOPMENT IN THE MOUNTAIN VALLEYS AFFECTING KAVL BY MID
MORNING.  KEPT PREVIOUS FM GROUP MENTION OF MVFR RESTRICTIONS WITH A
4HR TEMPO FOR IFR CONDITIONS.  OTHERWISE...ABOVE MENTIONED DOWNSLOPE
FLOW WILL KEEP SKIES CLEAR FOR THE MOST PART ASIDE FOR POSSIBLE LOW
VFR CU AT KAVL.  WINDS WILL REMAIN LIGHT AND NORTH/NORTHWESTERLY.

OUTLOOK...THE AIRMASS WILL MODIFY MID TO LATE WEEK TO GRADUALLY
SUPPORT RETURNING ISOLD TO SCT DIURNAL THUNDERSTORMS...ESPECIALLY
ACROSS THE MTNS. MORNING LOW CLOUDS AND FOG WILL BE POSSIBLE...
ESPECIALLY IN THE MTN VALLEYS.

CONFIDENCE TABLE...

            23-05Z        05-11Z        11-17Z        17-23Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  83%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  83%
KAVL       HIGH 100%     HIGH  85%     HIGH  86%     HIGH  83%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  83%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  83%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH  83%

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...JOH
NEAR TERM...CDG/JAT
SHORT TERM...LG
LONG TERM...LG
AVIATION...CDG






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