Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 231426
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1026 AM EDT SAT MAY 23 2015

.SYNOPSIS...
DRY CANADIAN HIGH PRESSURE WILL LINGER ATOP THE REGION THROUGH THE
HOLIDAY WEEKEND. A SOUTHERLY FLOW OF MOISTURE AROUND BERMUDA HIGH
PRESSURE WILL GRADUALLY RETURN NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM EDT SATURDAY...BEAUTIFUL DAY UNFOLDING ACROSS THE
REGION WITH TEMPERATURES SLOWLY RISING INTO THE UPPER 60S TO LOWER
70S WITH LOW RH UNDER A FEW HIGH LEVEL CIRRUS.  WINDS ARE STILL
EXPECTED TO INCREASE INTO THE 5-7KTS RANGE THIS AFTERNOON ALL THE
WHILE VEERING SOUTHEAST AS THE PRIMARY SFC RIDGE SHIFTS EAST.
THUS...CURRENT FCST LOOKS GOOD WITH NO CHANGES NEEDED/MADE WITH THIS
UPDATE.

PREVIOUS DISCUSSION...

AS OF 230 AM...AN UPPER RIDGE WILL CONTINUE TO BUILD ALONG A
NEGATIVELY-TILTED AXIS FROM FL TO TO MN. THE HEIGHT RISES ATOP THE
CWFA WILL HELP KEEP THINGS DRY WITH SUNNY TO MOSTLY SUNNY SKIES. THE
CENTER OF SFC HIGH PRESSURE WILL SHIFT FROM THE CENTRAL APPALACHIANS
THIS MORNING...TO JUST OFF THE MID ATLANTIC COAST TONIGHT. SO WITH
FLOW TURNING OUT OF THE SOUTHEAST...TEMPS WILL BE A CATEGORY OR TWO
WARMER TODAY THAN YESTERDAY...STILL ABOUT A CATEGORY BELOW NORMAL
FOR MOST LOCATIONS. LOWS TONIGHT UNDER MOSTLY CLEAR SKIES WILL BE
NEAR NORMAL.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 150 AM SATURDAY...DRY WX WILL CONTINUE ON SUNDAY AS UPPER RIDGE
AXIS CONTINUES TO BUILD ATOP THE SE CONUS. LLVL FLOW AROUND BERMUDA
HIPRES WILL STEADILY ADVECT HIGHER TEMPERATURES AND DWPTS INTO THE
SOUTHERN APPALACHIANS. TEMPS WILL BE A FEW DEGREES WARMER THAN
SATURDAY TOPPING OUT A FEW DEGREES ABOVE NORMAL. THE UPPER PATTERN
EVOLVES SLOWLY ON MONDAY WITH THE RIDGE AXIS SHARPENING AND MOVING
EAST CLOSER TO THE COAST. THIS COMBINED WITH A STEADY INCREASE IN
LOW LEVEL MOISTURE DUE TO THE INCREASING SLY FLOW AROUND THE
WEAKENING RIDGE AXIS OF THE SFC BERMUDA HIGH WILL CREATE INCREASING
INSTABILITY AND CHC OF MAINLY DIURNAL CONVECTION. BEST CHC WILL BE
ACROSS THE NC MTNS...NE GA AND UPSTATE WEST OF I-26...WITH LITTLE TO
NO CHC OVER THE I-77 CORRIDOR WHERE THE SUPPRESSIVE EFFECTS OF THE
RIDGE CONTINUE. HIGHS MON REMAIN NEARLY STEADY WEST AND RISE A
COUPLE OF DEGREES EAST.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 255 AM SAT...THE MEDIUM RANGE CONTINUES TO LOOK SUMMER-LIKE
WITH AN UPPER RIDGE AXIS ALONG THE ATLANTIC COAST AND A SFC BERMUDA
HIGH ACROSS THE SE KEEPING A GENERALLY MOIST FLOW FROM THE GULF AND
ATLANTIC AT LOW LEVELS ACROSS THE CWFA. THIS WILL FAVOR ABOVE NORMAL
TEMPS AND MAINLY DIURNAL SHOWERS AND STORMS EACH DAY. THE GFS
CONTINUES TO FORECAST THE RIDGE BREAKING DOWN LATE IN THE PERIOD
ALLOWING SHORT WAVE ENERGY AND A WEAK COLD FRONT TO MOVE INTO THE
AREA. THE ECMWF CONTINUES TO FORECAST THE UPPER RIDGE/BERMUDA HIGH
PATTERN RIGHT THRU THE FORECAST PERIOD. GIVEN THE DISCREPANCY...HAVE
TRENDED TOWARD THE MORE STEADY ECMWF FCST. CONVECTIVE COVERAGE WILL
BE HIGHER ACROSS THE MTNS AND WRN CWFA EACH DAY WHERE BETTER
MOISTURE AND INSTABILITY REMAIN FARTHER FROM THE UPPER RIDGE AXIS.
THE CHANCES FOR SEVERE THUNDERSTORMS EACH DAY LOOK MINIMAL AT THIS
POINT BECAUSE OF POOR LAPSE RATES AND RELATIVELY WEAK INSTABILITY
WITH MID LEVEL WARM AIR.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT AND ELSEWHERE...NO MAJOR CHANGES FOR THE 12Z TAFS. THE
CENTER OF DRY HIGH PRESSURE WILL SHIFT FROM THE APPALACHIANS TO THE
EAST COAST TODAY...KEEPING DRY AIR IN PLACE...BUT SHIFTING THE WINDS
FROM NE TO SE BY THIS AFTN. WINDS SHUD REMAIN LIGHT...PICKING UP TO
AROUND 5-7 KT THIS AFTN. OTHER THAN A FEW PERIODS OF CIRRUS...NOT
EXPECTING ANY OTHER CLOUDS OR FOG AT ANY OF THE TAF SITES THRU
TONIGHT.

OUTLOOK...HIGH PRESSURE WILL SHIFT EAST OFF THE EAST COAST EARLY
NEXT WEEK...ALLOWING MOISTURE TO GRADUALLY RETURN OUT OF THE SOUTH.
CONDITIONS SHOULD REMAIN GENERALLY FAIR THROUGH THE PERIOD.

CONFIDENCE TABLE...

            14-20Z        20-02Z        02-08Z        08-12Z
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...CSH
NEAR TERM...ARK/CDG
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK



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