Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 200718
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
318 AM EDT SUN APR 20 2014

.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS IN TODAY THROUGH MONDAY BEHIND...AS LOW
PRESSURE DRIFTS EAST OF THE AREA. A COLD FRONT WILL CROSS THE REGION
ON TUESDAY...FOLLOWED BY DRY HIGH PRESSURE FOR WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE REGION ON
FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 255 AM EDT...REGIONAL RADARS SHOW ONE LAST DIMINISHING BAND OF
LIGHT RAIN MOVING THROUGH THE SE SIDE OF CHARLOTTE EARLY THIS
MORNING. ALL MESOSCALE MODELS DEPICT COVERAGE SLOWLY DIMINISHING
THROUGH THE EARLY MORNING HOURS AS THE DEFORMATION ZONE DISSIPATES
AND SLIPS EAST. MEANWHILE...WATER VAPOR IMAGERY SHOWS THE SWIRLING
UPPER LOW MOVING OVER THE OFFSHORE WATERS EAST OF SAVANNAH EARLY
THIS MORNING. AS THIS UPPER VORTEX MOVES FARTHER OFFSHORE
TODAY...RIDGING WILL BUILD IN FROM THE WEST. GRADUAL SCATTERING OF
THE CLOUDS WILL ALLOW TEMPS TO REBOUND DESPITE THE LINGERING SFC
HIGH PRES RIDGE REMAINING IN PLACE. THE NAM HAS MORE EASTERLY FLOW
MOISTURE AT 850 MB TONIGHT...BUT THE PREFERRED GFS/ECM CAMP KEEP THE
MOISTURE CONFINED MORE TO THE COASTAL PLAIN. EXPECT MAXES IN THE 60S
THIS AFTN AND MINS IN THE 40S TONIGHT.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM EDT SUNDAY...THE SHALLOW UPPER RIDGE WILL MOVE MORE
SQUARELY OVER THE REGION ON MONDAY...WHILE SFC HIGH PRESSURE SLOWLY
WEAKENS. ANTICIPATE MAXES TO REBOUND TO NEAR OR SLIGHTLY ABOVE
CLIMO. THE NEXT UPSTREAM TROUGH AXIS EJECTING EASTWARD FROM THE
PLAINS WILL APPROACH THE APPALACHIANS MON NIGHT AND CROSS THE
FORECAST AREA ON TUE ALONG WITH AN ATTENDANT COLD FRONT. INSTABILITY
WILL BUBBLE UP IN PIEDMONT SECTIONS TO SUPPORT PRE/FRONTAL AFTN TSRA
TUE...BUT SHEAR PROFILES APPEAR TOO WEAK FOR MUCH OF A SEVERE
THREAT. SHOWER CHANCES WILL END QUICKLY TUE EVENING...WITH MIN TEMPS
FALLING INTO THE UPPER 30S AT SOME HIGHER RIDGE TOPS EARLY WED
MORNING. HOWEVER...NO FROST OR FREEZE IS EXPECTED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM SUNDAY...A SHARP UPR RIDGE AXIS WILL CROSS THE AREA
THURSDAY....FOLLOWED BY ANOTHER POTENT SHORTWAVE TROF...WHICH WILL
LIFT NE INTO THE GREAT LAKES ON FRIDAY. AT THE SFC...DRY HIGH PRES
BUILDS IN FROM THE NORTH WEDNESDAY AND THURSDAY...GRADUALLY SHIFTING
SOUTHEAST OF THE AREA TO ALLOW AN INCREASING RETURN FLOW ATOP THE
CWFA BY FRIDAY. LOW PRES DEEPENS OVER THE WESTERN GREAT LAKES
THURSDAY INTO FRIDAY...WITH A TRAILING COLD FRONT PUSHING ACRS THE
OH/TN VLYS. MODELS ARE IN GOOD AGREEMENT ON THE FRONT PUSHING THRU
THE CWFA ON FRIDAY WITH A LITTLE MORE INSTBY/SHEAR AND FORCING TO
WORK WITH COMPARED TO THE FRONT THAT IS EXPECTED TO CROSS ON
TUESDAY. STILL...IT DOES LOOK LIKE MOISTURE WILL STILL BE SOMEWHAT
LIMITED...AND THAT FAR OUT IN THE EXTENDED...THE SEVERE WX THREAT IS
STILL UNCERTAIN. THE FRONT SHUD PUSH THRU THE AREA BY EARLY
SATURDAY...WITH DRY WX. TEMPS LOOK TO BE A CATEGORY OR TWO COOLER
THAN TUESDAY FOR BOTH WEDNESDAY AND THURSDAY...WHICH IS NEAR NORMAL.
THEN TEMPS WARM BACK ABOVE NORMAL FOR FRIDAY AND SATURDAY.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AT KCLT...LIGHT RAIN IN THE LINGERING DEFORMATION ZONE NEAR THE
AIRFIELD WILL CONTINUE THROUGH 09Z BEFORE DISSIPATING. LOW LEVEL DRY
AIR ADVECTING IN ON NE FLOW IS KEEPING CIGS AND VSBY VFR EVEN WHILE
PRECIPITATION IS FALLING...SO WILL RIDE ON VFR THROUGH THE MORNING
HOURS. OCCASIONAL GUSTS ARE LIKELY IN THE NE FLOW...BUT WITH BETTER
GUSTS DEVELOPING THROUGH THE DAY WITH MIXING. WILL ALLOW VFR CIGS TO
SCATTER OUT BY 16Z AND THEN LEAN TOWARD LESS CLOUDS AS INDICATED ON
THE GFS/ECM THROUGH THE EVENING HOURS.

ELSEWHERE...ALL LINGERING DEFORMATION ZONE PRECIPITATION SHOULD
REMAIN EAST OF THE FOOTHILL AND MTN TAF SITES THROUGH THE EARLY
MORNING HOURS. IN ADDITION...SLIGHTLY DRIER AIR ADVECTING IN ON NE
FLOW IS KEEPING VSBY AND CIGS AT VFR LEVELS AND THIS SHOULD PERSIST.
KAVL TO KAND ARE THE SITES OF MOST CONCERN. KAVL WILL BE SHELTERED
TO THE DRIER NE FLOW...AND KAND WILL SEE SLIGHTLY LESS BOUNDARY
LAYER DRYING. THESE LOCATIONS COULD EXPERIENCE BRIEF MVFR CONDITIONS
BUT CONFIDENCE IS TOO LOW TO FEATURE THIS AT THE MOMENT. EXPECT
OCCASIONAL GUSTS ON NE FLOW AT THE UPSTATE TAF SITES
TODAY...ESPECIALLY THIS AFTN WITH MIXING.

OUTLOOK...DRY HIGH PRES WILL DEVELOP THROUGH MONDAY. A FAIRLY WET
FRONTAL SYSTEM...WITH PIEDMONT THUNDERSTORMS...IS EXPECTED ON
TUE...WITH DRYING RETURNING MID WEEK.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-07Z
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...ARK
NEAR TERM...HG
SHORT TERM...HG
LONG TERM...ARK
AVIATION...HG






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