Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 291315
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
915 AM EDT MON JUN 29 2015

.SYNOPSIS...
MOISTURE WILL GRADUALLY RETURN TO THE REGION STARTING TODAY WITH
THE NEXT FRONT APPROACHING BY THE MIDDLE OF THE WEEK. THIS WILL LEAD
TO INCREASED SHOWER AND THUNDERSTORM CHANCES TUESDAY AND WEDNESDAY
WITH HIGH TEMPERATURES RETURNING TO NEAR NORMAL LEVELS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM...TEMPERATURES HAVE WARMED QUICKLY FROM GENERALLY COOL
MORNING TEMPERATURES...RISING 10 TO 15 DEGREES FROM MINS. I WILL
UPDATE THE FORECAST TO ADJUST HOURLY TEMPERATURES TO OBSERVATIONS.
RECENT MESOSCALE ANALYSIS INDICATED A WEAK LOW NEAR THE NC/SC STATE
LINE OVER THE PEE DEE REGION. A WEAK FRONT ASSOCIATED WITH THE LOW
DRAPED SW ACROSS THE SC/GA ACROSS THE COASTAL PLAIN. THE DEPARTING
LOW SHOULD SUPPORT WEAK NE WINDS THROUGH MOST OF THE MORNING.
HOWEVER...RETURN SW FLOW SHOULD DEVELOP EARLY THIS AFTERNOON AND
REMAIN INTO THE EVENING. I WILL UPDATE TO ADJUST WIND TIMING AND
SPEED.

0830 UTC UPDATE...SKY COVER WAS UPDATED PER INFRARED SATELLITE
IMAGERY TO ACCOUNT FOR A THIN STREAK OF HIGH CLOUDS MOVING NORTHEAST
FROM THE GULF STATES.

AS OF 300 AM...AN ANOMALOUS HIGH AMPLITUDE UPPER TROUGH WILL BE
OVER EASTERN NORTH AMERICA TODAY AND TONIGHT. WEAK SHORTWAVE ENERGY
MOVING THROUGH THIS TROUGH WILL CROSS THE SOUTHERN APPALACHIANS THIS
EVENING AND AGAIN AROUND TUESDAY MORNING. LOW LEVEL MOISTURE
ASSOCIATED WITH THE REMAINS OF A FRONT NOW IN THE MS RIVER VALLEY
WILL REACH THE MOUNTAINS BY MIDDAY...SPREADING ACROSS THE AREA THIS
AFTERNOON...AND PERSISTING INTO TONIGHT. INSTABILITY WILL BE BEST IN
THE MOUNTAINS...CLOSEST TO THE TROUGH AXIS...AND THIS IS WHERE THE
GREATEST THUNDERSTORMS COVERAGE WILL BE CARRIED. ALTHOUGH CAPE IS
RATHER LIMITED...SOME SHEAR WILL EXIST. STEERING FLOW WILL KEEP
CELLS MOVING...AND LOW LEVEL FLOW WILL BE NEARLY PARALLEL TO THE
BLUE RIDGE...LIMITING UPSLOPE FLOW. TEMPERATURES WILL RUN SLIGHTLY
BELOW NORMAL IN A RELATIVELY COOL AIRMASS AND BELOW NORMAL HEIGHTS
ALOFT.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 130 AM MONDAY...THE AMPLIFIED PATTERN WILL LINGER THROUGH THE
PERIOD WITH MEAN L/WV TROUGH AXIS ATOP THE EASTERN CONUS.
EXPECTEDLY...THE DEEP LAYERED FLOW WILL BE UNSEASONABLY QUICK AND
AVERAGE FROM THE WSW. WITHIN THE WSW LLVL FLOW...MOISTURE RETURN AND
DESTABILIZATION WILL BE MODEST...YET STEADY...ALLOWING DAILY
DIURNALLY ENHANCED TSTMS TO INCREASE EACH DAY TO ABOVE CLIMO
VALUES. GIVEN THE ABNORMALLY AMPLIFIED FLOW FOR THIS TIME OF
THE YEAR...SFC-6 KM SHEAR VALUES WILL GIVE RISE TO POTENTIAL
FOR ORGANIZED DEEP CONVECTION EACH AFTERNOON/EVENING LEADING
TO SCATTERED SVR TSTMS. TEMPERATURES EACH DAY WILL BE CLOSE TO
PERSISTENCE AND THE LATE JUNE CLIMO.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 215 AM MONDAY...IT IS LOOKING LIKE THERE WILL BE A SLOW/TOKEN
RISE IN HEIGHTS ATOP THE REGION FOR THE LATTER HALF OF THE
WORKWEEK...PROBABLY KEEPING THE PROGGED WAVY FRONT/BAROCLINIC
ZONE EXTENDING FROM THE OHIO VALLEY TO MID-ATLANTIC OFF TO OUR
NORTH. HOWEVER...WITH SOME DEGREE OF ABNORMAL AMPLIFICATION TO
THE MEAN PATTERN TO START OFF JULY...DAILY THUNDERSTORM CHANCES
SHOULD AVERAGE HIGHER THEN CLIMO. HEADING INTO THE HOLIDAY
WEEKEND...IT REMAINS TO BE SEEN HOW FAR INTO THE SE CONUS THAT
BERMUDA HIPRES ASSERTS ITSELF...BUT AT THIS POINT...THERE/S REALLY
NO REASON TO DEVIATE FROM THE INHERITED FCST WHICH IS TYPICAL EARLY
JULY CONDITIONS.

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...
AT KCLT...VFR. THIN HIGH CLOUDS WILL MOVE BY FROM SW THE THIS
MORNING. LOW VFR CLOUDS AHEAD OF THE REMAINS OF A COLD FRONT WILL
APPROACH FROM THE WEST DURING THE DAY...BECOMING A SCATTERED LAYER
LATE TONIGHT. PRECIPITATION THIS AFTERNOON AND EVENING ASSOCIATED
THE APPROACHING SURFACE BOUNDARY AND A MID LEVEL SYSTEM WILL STAY
CLOSE TO THE MOUNTAINS IN BETTER INSTABILITY. WINDS WILL VEER FROM N
TO NE THROUGH EARLY MORNING...THEN TO S AND SW THIS AFTERNOON IN
ADVANCE OF THE ADVANCING SURFACE BOUNDARY. GUIDANCE IS NOT
SUPPORTIVE OF FOG RESTRICTIONS EITHER THIS MORNING OR TUESDAY
MORNING.

ELSEWHERE...VFR. THERE IS LIMITED GUIDANCE SUPPORT FOR A DAYBREAK
FOG RESTRICTION AT KAVL THIS MORNING AND TUESDAY MORNING...BUT THE
MODEL CONSENSUS IS VFR. LIMITED HIGH CLOUD COVERAGE MOVING UP FROM
THE SW WILL PASS OVER FOOTHILLS SITES THIS MORNING. LOW VFR CLOUDS
ASSOCIATED WITH THE REMNANTS OF A FRONT WILL START TO ARRIVE
TODAY...BECOMING A SCATTERED CLOUD LAYER TONIGHT. PRECIPITATION
ASSOCIATED WITH THE MID LEVEL SYSTEM MAY REACH ASHEVILLE...BUT BY
THE TIME IT DOES SO THIS EVENING...INSTABILITY SHOULD HAVE WANED
ENOUGH TO PRECLUDE THUNDER. IN ANY EVENT...CHANCES ARE TOO LOW FOR A
MENTION IN THE TAF. WINDS WILL VEER FORM THE N AND NE THIS MORNING
TO SE AND THEN SW THIS AFTERNOON.

OUTLOOK...A LINGERING BERMUDA HIGH COMBINED WITH AN AMPLIFYING
LONGWAVE TROF OVER THE SOUTHEAST WILL GRADUALLY INCREASE MOISTURE
AND INSTABILITY THROUGH MOST OF THE WORK WEEK. THUNDERSTORM COVERAGE
MAY INCREASE EACH DAY THROUGH WEDNESDAY...WITH SCT TO NUM DIURNAL
THUNDERSTORMS LATE IN THE WEEK. RESTRICTIONS MAY OCCUR WITH PASSING
STORMS...AND EACH MORNING OVER AREAS OF WET SOIL.

CONFIDENCE TABLE...

            13-19Z        19-01Z        01-07Z        07-12Z
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  96%
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...CSH
AVIATION...JAT


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