Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 230540
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
140 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 TODAY/...
AS OF 1040 PM...THE FORECAST REMAINS IN GREAT SHAPE. I WILL MAKE
SMALL TWEAKS TO SKY TRENDS TO ACCOUNT FOR APPROACHING CIRRUS.
OTHERWISE...SMALL EDITS WILL BE MADE IN THE HRLY TEMPS AND WINDS.

AS OF 715 PM...THE FORECAST REMAINS ON TRACK. I WILL UPDATE TO
ADJUST HRLY TEMPERATURES THROUGH TONIGHT. OVERALL...TONIGHT SHOULD
BE CALM...DRY...AND PASSING BANDS OF THIN HIGH CLOUDS.

AS OF 5 PM...NICE CONDITIONS ACROSS THE REGION PROVIDE LITTLE REASON
TO UPDATE THE FORECAST. RECENT SATELLITE IMAGES AND VIEW OUT THE
WINDOWS INDICATED A PATCH OF CIRRUS/WAVE CLOUDS ACROSS THE NC/SC
STATE LINE ACROSS THE FOOTHILLS AND PIEDMONT. I WILL UPDATE THE
FORECAST TO INDICATE THAT CLOUD COVER MAY REMAIN FOR A COUPLE OF
HOURS. MINOR EDITS MADE TO HOURLY TEMP AND DEWPOINTS LATE THIS
AFTERNOON.

AS OF 200 PM EDT FRIDAY...AN APPROACHING UPPER RIDGE AXIS WILL ALLOW
HEIGHTS TO CONTINUALLY RISE THROUGH THE PERIOD.  A SURFACE RIDGE
SLIDING THROUGH THE NORTHERN OHIO VALLEY REGION WILL CONTINUE TO
ADVECT EAST TONIGHT...THROUGH THE DAY ON SATURDAY ALLOWING FOR A
WEAK BACK DOOR REINFORCING FRONT TO PUSH INTO NORTHEAST GA AND THE
WESTERN CAROLINAS.  THUS...THE ENTIRE FCST REMAINS DRY WITH BELOW
NORMAL TEMPERATURES AND LIGHT GRADUALLY VEERING WINDS HIGHLIGHTING
THE PERIOD.  EXPECTING CLEAR SKIES TO PREVAIL OVERNIGHT TONIGHT
LEADING TO ABUNDANT RADIATIONAL COOLING...THEREFORE TEMPERATURES
WERE POPULATED FROM A CONSENSUS OF RAW GUIDANCE WHICH WAS 3-5
DEGREES COOLER THAN MOSGUIDE.  EXPECTING LOWS TONIGHT IN THE UPPER
40S TO LOWER 50S OVER THE LOWER TERRAIN...WHILE SOME VALUES IN THE
LOWER/MID 30S ARE EXPECTED OVER THE HIGHER ELEVATIONS.  HIGHS ON
SATURDAY WILL BE SLIGHTLY WARMER THAN TODAY...HOWEVER STILL APPROX 3-
5 DEGREES BELOW CLIMO WITH DEWPOINTS IN THE 40S SUPPORTING LOW
HUMIDITY LEVELS.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 210 PM FRIDAY...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. MAXIMUMS WILL BE A FEW DEG F WARMER
THAN SATURDAY TOPPING OUT A BIT ABOVE CLIMO. THE UPPER PATTERN
EVOLVES SLOWLY ON MONDAY WITH THE RIDGE AXIS SHARPENING. IT IS
DEBATABLE HOW JUST FAR WEST IT/S SUPPRESSIVE EFFECTS LINGER THROUGH
SUNSET BUT THE STEADY INCREASE IN LLVL MOISTURE LEADS THE MODEL
CONSENSUS TO FAVOR AT LEAST ISOLATED DIURNAL DEEP CONVECTION IN
AND/OR NEAR THE HIGH TERRAIN. TEMPERATURES ARE SLATED TO CONTINUE TO
RISE 2-3 DEG F ABOVE SUNDAY/S READINGS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 215 PM FRI...THE MEDIUM RANGE CONTINUES TO LOOK SUMMER-LIKE
WITH AN UPPER RIDGE/ANTICYCLONE HOLDING ALONG THE SOUTHEAST COAST
AND A BERMUDA HIGH AT THE SURFACE PROVIDING A GENERALLY MOIST FLOW
FROM THE GULF/ATLANTIC AT LOW LEVELS. THIS WILL FAVOR ABOVE NORMAL
TEMPS AND MAINLY DIURNAL SHOWERS AND STORMS EACH DAY. THERE IS SOME
DISCREPANCY IN THE MODELS ON THURSDAY...FOR WHAT IT IS WORTH...IN
TERMS OF THE TIMING AND STRENGTH OF A SHORT WAVE MOVING ACROSS THE
MIDWEST/OH VALLEY. THIS FEATURE COULD PUSH A WEAK BOUNDARY INTO THE
AREA ON WEDNESDAY EVENING OR THURSDAY WHICH WOULD ENHANCE PRECIP
CHANCES MAINLY OVER THE MTNS...HENCE THE LIKELY POP OVER PARTS OF
THE MTNS BOTH DAYS. CHANCES MAY GO DOWN A BIT FOR FRIDAY IF THAT
BOUNDARY ACTUALLY MOVES THRU. 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 /06Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT AND ELSEWHERE...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.

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...

            05-11Z        11-17Z        17-23Z        23-00Z
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...NED
SHORT TERM...CSH
LONG TERM...PM
AVIATION...ARK



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