Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 022332
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
732 PM EDT WED SEP 2 2015

.SYNOPSIS...
A WEAK PRESSURE PATTERN WILL LINGER ATOP THE REGION FOR THE REST OF
THE WORKWEEK. LATE SUMMER WARMTH AND DAILY THUNDERSTORM CHANCES WILL
BE THE MAIN FEATURES OF INTEREST. A BACK DOOR COLD FRONT IS EXPECTED
TO PUSH ACROSS THE REGION ON FRIDAY FOLLOWED BY A COOL AND MOIST
AREA OF HIGH PRESSURE THIS WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 730 PM...STILL A COUPLE OF SHOWERS AND THUNDERSTORMS ACROSS
THE FORECAST AREA THIS EVENING...BUT COVERAGE AND INTENSITY HAS BEEN
STEADILY TRENDING DOWN OVER THE PAST COUPLE OF HOURS...AND EXPECT
LINGERING ACTIVITY TO DISSIPATE BY LATE EVENING.

AS OF 230 PM WEDNESDAY...MEAN UPPER RIDGE WILL REMAIN IN PLACE OVER
THE EASTERN HALF OF THE COUNTRY. OUR AREA IS LEFT IN WEAK NORTHWEST
FLOW ALOFT WITH INTERMITTENT SHORTWAVES RIDING DOWN THE FLOW. ONE
WILL DIVE DOWN TOWARD THE CAROLINA COASTS TONIGHT...WHILE ANOTHER
PIECE OF ENERGY FROM THE LOWER MISSISSIPPI VALLEY WILL GET PICKED UP
BY THE MEAN FLOW...TRAVERSING THE TENNESSEE VALLEY AND WORKING ITS
WAY TOWARD THE CAROLINAS EARLY THURSDAY MORNING. THIS WILL BRING
WITH IT SOME MID-LEVEL MOISTURE THAT WILL SERVE TO INCREASE CLOUD
COVER OVERNIGHT...THUS KEEPING LOWS SEVERAL DEGREES ABOVE SEASONAL
NORMALS. A VERY VERY WEAK SURFACE BOUNDARY WILL PUSH THROUGH
TOMORROW AS WELL AND DESPITE SURFACE WINDS SHIFTING AROUND TO THE
NORTHEAST...SEEMS SLIGHT TO LOW CHANCE POPS ARE WARRANTED ACROSS THE
AREA TOMORROW TO ACCOUNT FOR THE ADDITIONAL LIFT ASSOCIATED WITH THE
SHORTWAVE AND FRONT. SOME WEAK OROGRAPHIC LIFT MAY SERVE TO ENHANCE
CONVECTION ESPECIALLY ACROSS THE SOUTHERN MOUNTAINS AS WELL. DESPITE
ALL THIS...HIGHS WILL CONTINUE TO HOVER ABOVE SEASONAL NORMALS WITH
LOW 90S ACROSS THE UPSTATE AND PIEDMONT AND 80S ACROSS ALL BUT THE
HIGHEST ELEVATIONS OF THE MOUNTAINS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM WEDNESDAY...AN UPPER LEVEL HIGH WILL BEGIN TO
STRENGTHEN OVER THE NORTHEAST STATES...WHILE A RELATIVE WEAKNESS
WILL LINGER AROUND ITS WESTERN AND SOUTHERN PERIPHERY...EXTENDING
FROM THE OHIO VALLEY TO THE SOUTHEAST STATES. THIS WILL PLACE THE
CWFA WITHIN VERY WEAK MID AND UPPER LEVEL FLOW THRU THE SHORT TERM.
AT THE SFC...HIGH PRES WILL BUILD OVER NEW ENGLAND...RIDGING
SOUTHWESTWARD THRU THE CAROLINAS. A WEAK BACK DOOR COLD FRONT WILL
PUSH THRU THURSDAY NIGHT...WITH GRADUALLY INCREASING NORTHEASTERLY
TO EASTERLY LLVL FLOW FRIDAY THRU SATURDAY. GUIDANCE IS IN PRETTY
GOOD AGREEMENT ON THE FLOW TRANSPORTING INCREASING LOW-MID LVL
MOISTURE. THIS COMBINED WITH FALLING HEIGHTS ALOFT SHUD RESULT IN AN
INCREASE IN INSTBY FOR FRIDAY AND SATURDAY. THE EASTERLY FLOW WILL
ALSO ENHANCE UPSLOPE FORCING ALONG THE BLUE RIDGE FOR LIFT. SO I
WILL FCST A SHOTGUN CHC POP ON FRIDAY...WITH SLIGHTLY HIGHER VALUES
IN THE HIGH TERRAIN...AND SOLID CHC TO LOW-LIKELY POP FOR SATURDAY.
THIS IS NOT MUCH CHANGE FROM PREVIOUS FCST. FRIDAY STILL LOOKS TO
SEE ABOVE NORMAL TEMPS...AS THICKNESSES DON/T FALL MUCH UNTIL
SATURDAY. MORE CLOUD COVER AND PRECIP ON SATURDAY WILL RESULT IN
TEMPS ABOUT A CATEGORY BELOW NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 100 PM WEDNESDAY...THE LATEST MEDIUM RANGE GUIDANCE SUPPORTS
THE GOING THINKING OF SFC RIDGING CONTINUING TO NOSE SSWD INTO THE
CWFA THROUGH SUNDAY. THE PROGGED PRESSURE GRADIENT LOOKS SIMILAR TO
SATURDAY...BUT THINKING CLOUDS WILL BE A TAD THINNER WITH MAXIMUM
TEMPERATURES A HAIR WARMER. WITH SFC PRESSURES FCST TO RISE ON LABOR
DAY MONDAY...PROGRESSIVELY LESS CLOUD COVER AND MAX TEMPERATURES
CLIMBING TOWARD CLIMO IS EXPECTED. THE INHERITED CLIMO RANGE...
DIURNALLY ENHANCED DEEP CONVECTIVE CHANCES WILL REMAIN AS IS.
BACK TO MORE TYPICAL LATE SUMMER CONDITIONS ON TUESDAY FEATURING
TEMPERATURES AND POP NEAR CLIMO WITH AN INCREASE IN RETURN FLOW
PROMPTING GREATER TSTM CHANCES FOR THE NEW DAY 7.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AT KCLT AND ELSEWHERE...ISOLATED SHOWERS AND SOME TS WILL DISSIPATE
OVER THE NEXT COUPLE OF HOURS...AND SHOULD REMAIN WELL-DISPLACED
FROM THE TERMINALS DURING THIS TIME. VFR CONDITIONS ARE EXPECTED
THROUGH THE PERIOD...EXCEPT PERHAPS AT KAVL...WHERE THE POTENTIAL
WILL EXIST FOR SOME FOG AND LOW STRATUS AROUND SUNRISE. EVEN
THERE...CONFIDENCE IS PRETTY LOW...AND HAVE ONLY INCLUDED A TEMPO
FOR 5SM/SCT004 FROM 10-12Z. OTHERWISE...OCCL VFR CU OR STRATOCU IN
THE 050-070 RANGE CAN BE EXPECTED OVER THE NEXT 24 HOURS. WINDS WILL
GENERALLY BE LIGHT AND VRBL THROUGH THE PERIOD. ANOTHER ROUND OF
ISOLATED TO WIDELY SCT SHOWERS AND TS ARE EXPECTED THURSDAY.
ALTHOUGH COVERAGE IS EXPECTED TO BE A LITTLE HIGHER THAN TODAY...
STILL NOT ENOUGH CONFIDENCE TO INCLUDE A MENTION IN THE TAFS ATTM.

OUTLOOK...A PATTERN OF DIURNAL ISOLATED/WIDELY SCT SHOWERS
AND THUNDERSTORMS IS EXPECTED TO CONTINUE THRU THE END OF THE
WORK WEEK. BY THE WEEKEND...A MOIST EASTERLY FLOW IS EXPECTED TO
DEVELOP...BRINGING BETTER CHANCES FOR SHOWERS AND RESTRICTIONS. LOW
CLOUDS AND FOG WILL BE POSSIBLE EACH NIGHT IN THE MOUNTAIN VALLEYS.

CONFIDENCE TABLE...

            23-05Z        05-11Z        11-17Z        17-18Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH  83%     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

&&

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

&&

$$
SYNOPSIS...CSH
NEAR TERM...JDL/TDP
SHORT TERM...ARK
LONG TERM...CSH
AVIATION...JDL


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