Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 261105
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
705 AM EDT SUN JUL 26 2015

.SYNOPSIS...
WEAK BERMUDA HIGH PRESSURE WILL REMAIN OVER THE AREA WITH TYPICAL
SUMMERTIME CONDITIONS TODAY. THE CENTER OF A STRONG MID LEVEL RIDGE
WILL SLIDE WEST THROUGH THE WEEK. A WEAK COLD FRONT WILL APPROACH
THE REGION BY THE END OF THE WORK WEEK...WITH INCREASE CHANCES FOR
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS FRIDAY AND SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM EDT...FOG AND LOW CLOUDS HAVE SET UP OVER THE MOUNTAIN
RIVER VALLEYS THIS MORNING AND WILL LIKELY LINGER UNTIL MID MORNING
BEFORE SCATTERING. OTHERWISE...A PROMINENT RIDGE WILL PERSIST OVER
TX AND THE SRN PLAINS TODAY...WITH A WEAK LOBE OF 500 MB VORTICITY
LIKELY CROSSING THE SOUTHERN APPALACHIANS LATE TODAY IN THE NW FLOW
ALOFT EAST OF THE RIDGE. ISOLATED TO SCATTERED CONVECTIVE COVERAGE
SHOULD BE CONFINED MAINLY TO THE MTNS THIS AFTN AND EVENING WHERE
LOW LEVEL CONVERGENCE AND WEAK UPSLOPE FLOW WILL CONTINUE IN
ADDITION TO THE UPPER SUPPORT. WARM PROFILES ALOFT AND MIXING OUT OF
SURFACE DEWPOINTS WILL CONTINUE TO MAKE COVERAGE SPARSE OVER THE
PIEDMONT...WHILE ISOLD SHOWERS OR TSTMS COULD ADVECT INTO THE
FOOTHILLS FROM THE MTNS GIVEN THE STEERING FLOW ALOFT. MAX TEMPS
SHOULD GAIN ANOTHER DEGREE OR TWO OVER SATURDAY VALUES IN MOST AREAS.

ANY EVENING ACTIVITY SHOULD WANE FAIRLY QUICKLY IN AND NEAR THE
MTNS...WITH DRY CONDITIONS OVERNIGHT. PATCHY STRATOCUMULUS MAY FAN
OUT ONCE AGAIN TONIGHT WITH MOISTURE TRAPPED BELOW A WEAK MID LEVEL
INVERSION IN THE PROFILES. ANOTHER ROUND OF LOW CLOUDS AND FOG IS
EXPECTED ACROSS THE MOUNTAIN VALLEYS...WITH MILD MIN TEMPS
THROUGHOUT.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
AS OF 230 AM SUNDAY...ON MONDAY...THE CENTER OF THE H5 RIDGE WILL
REMAIN OVER THE SOUTHERN PLAINS AS THE LONGWAVE TROUGH AXIS REMAINS
NEAR THE EAST COAST. SHORT RANGE MODELS INDICATE THAT LLVL FLOW WILL
REMAIN LIGHT AND VARIABLE...WITH SPEEDS LESS THAN 10 KTS BELOW H7.
GIVEN THE WEAK FLOW AND SW DIRECTION...THE POTENTIAL FOR A LEE SFC
TROF APPEARS LOW FOR MONDAY. FORECAST SOUNDINGS AND PLAIN MODEL VIEW
OF CAPE INDICATES THAT VALUES SHOULD RANGE FROM 800 TO 1500 J/KG.
THE ENVIRONMENT SHOULD SUPPORT SCT TSRA ACROSS THE HIGH PEAKS BY
EARLY AFTERNOON...DRIFTING SLOWLY EAST DURING THE MID TO LATE
AFTERNOON. I WILL FORECAST CHC POPS ACROSS THE MTNS WITH SCHC EAST.
HIGH TEMPERATURES ARE FORECAST TO RANGE 2 TO 3 DEGREES ABOVE NORMAL.

ON TUESDAY...THE ENVIRONMENT ACROSS THE REGION WILL CHANGE VERY
LITTLE FROM MONDAY. HOWEVER...WEAK RETURN FLOW SHOULD YIELD DEWPOINTS
A DEGREE OR TWO HIGHER THAN MONDAY. MODELS INDICATE PRIMARILY MTN
CONVECTION DURING THE MID AND LATE AFTERNOON. WEAK
SHEAR...INSTABILITY...AND HIGH WBZ SHOULD SUPPORT ONLY GENERAL TSRA
BOTH DAYS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...WEDNESDAY THROUGH SATURDAY...THE CENTER OF A MID
LEVEL HIGH WILL REMAIN OVER THE DESERT SW AS A LONGWAVE TROUGH
LINGERS OVER THE ATLANTIC COAST. MEDIUM RANGE MODELS SHOW THE
POTENTIAL FOR A MID LEVEL LOW DEVELOPING OVER NRN FL/SRN GA LATE IN
THE PERIOD. MODEL AGREEMENT AND CONSISTENCY WITH THE MID LEVEL LOW
REMAINS WEAK. LIGHT LLVL WINDS...WEAK INSTABILITY...AND ABSENT
TRIGGERS SHOULD YIELD DIURNAL MTN TSRAS WED AND THURS. FRI AND
SAT...A COLD FRONT SHOULD SLIDE NW TO SE ACROSS THE SRN
APPS...POSSIBLY BECOMING STATIONARY EAST OF THE MTNS. I WILL
FORECAST CHC POPS ACROSS THE CWA...HIGHER VALUES OVER THE MTNS ON
FRI...SHIFTING EAST OF THE MTNS ON SAT. THE PERIOD SHOULD BEGIN WITH
HIGHS SLIGHTLY ABOVE NORMAL ON WED TO SLIGHTLY BELOW NORMAL ON SAT.

&&

.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
AT KCLT...MORNING VFR STRATOCUMULUS CIGS SHOULD SCATTER THROUGH THE
DAY...WITH LITTLE TO NO CONVECTIVE CHANCES GIVEN DEWPOINTS MIXING
WELL IN THE LOWER 60S...IF NOT THE 50S. WINDS WILL REMAIN LIGHT FROM
THE SE THROUGH THE PERIOD.

ELSEWHERE...SCT TO BKN VFR STRATOCUMULUS IS EXPECTED ACROSS THE
FOOTHILL TAF SITES THROUGH THE MORNING HOURS...WHILE TEMPO IFR TO
LIFR RESTRICTIONS WILL OCCUR AT KAVL...WITH TEMPO IFR FOG AT KHKY
FOR A COUPLE OF HOURS. AFTN AND EVENING CONVECTION SHOULD BE LIMITED
TO THE MTNS TODAY...WITH WARM TEMPS ALOFT AND MIXED SURFACE
DEWPOINTS INHIBITING DEEP CONVECTION EAST OF THE MTNS. WILL FEATURE
VCTS AT KAVL AFTER 18Z. EXPECT LIGHT SE TO S WINDS THROUGHOUT DURING
THE PERIOD.

.OUTLOOK...MAINLY AFTN SCATTERED SHRA/TSRA ARE EXPECTED OVER THE
MTNS MON...WITH SMALLER CHANCES EAST. EARLY MORNING FOG/STRATUS WILL
ALSO BE POSSIBLE EACH DAY MAINLY IN THE MTN VALLEYS. PRECIPITATION
CHANCES GRADUALLY INCREASE THROUGH THE WORK WEEK.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  94%     HIGH 100%     HIGH 100%     MED   66%
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...NED
NEAR TERM...HG
SHORT TERM...NED
LONG TERM...NED
AVIATION...HG


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