Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 051043
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
643 AM EDT WED AUG 5 2015

.SYNOPSIS...
A WEAK COLD FRONT WILL DRIFT SOUTH INTO OUR AREA TODAY BECOMING
NEARLY STATIONARY. AS MOISTURE INCREASES ACROSS OUR REGION...A
STRONG DISTURBANCE WILL REACH THE WESTERN CAROLINAS AND NORTHEAST
GEORGIA THURSDAY. THIS DISTURBANCE SHOULD BE EAST OF OUR AREA ON
FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM...A BRIEF BREAK IN THE THICKER CIRRUS THIS MORNING WILL
BE SHORT LIVED AS MID AND HIGH LEVEL MOISTURE RETURN AHEAD OF AN
APPROACHING SHORT WAVE. PATCHY FOG HAS FORMED IN SOME OF THE MTN
VALLEYS AND NORMALLY MORE FOGGY SITES OUTSIDE OF THE MTNS. THIS WILL
LIFT QUICKLY AFTER DAYBREAK. OTHERWISE...GOING FCST ON TRACK WITH
UPDATES MAINLY FOR CURRENT CONDITIONS.

AS OF 320 AM...NEARLY ZONAL FLOW ALOFT WILL BRING A RELATIVELY
STRONG SHORT WAVE ACROSS THE AREA LATE THIS AFTERNOON AND EARLY
EVENING. AT THE SFC...A STALLED FRONTAL BOUNDARY ACROSS THE AREA
WILL PROVIDE A LOW LEVEL FOCUS FOR CONVECTION AS WELL. DEW POINTS
WILL MIX OUT AGAIN THIS AFTERNOON. HOWEVER...THEY WILL REMAIN IN THE
60S INSTEAD OF DROPPING INTO THE 50S. THIS COMBINED WITH STEEPENING
MID LEVEL LAPSE RATES FROM THE COOLER MID LEVEL AIR ASSOCIATED WITH
THE SHORT WAVE WILL LEAD TO MODERATE INSTABILITY ACROSS THE MTNS AND
APPROACHING MODERATE ELSEWHERE. EXPECT THE BEST COVERAGE TO BE
ACROSS THE MTNS...BUT SCT COVERAGE SHOULD DEVELOP OUTSIDE OF THE
MTNS AS WELL DURING THE LATE AFTERNOON AND EARLY EVENING AS THE
SHORT WAVE MOVES THRU. SCT COVERAGE WILL SLOWLY RETREAT TO THE MTNS
OVERNIGHT AS THE SHORT WAVE MOVES EAST AND MCS ACTIVITY APPROACHES.
ISOLATED SEVERE STORMS WILL BE POSSIBLE...ESPECIALLY ACROSS THE MTNS
WHERE INSTABILITY AND SHEAR BECOME MODERATE. WILL BE ANOTHER VERY
HOT DAY WITH HIGHS WELL INTO THE 90S OUTSIDE OF THE MTNS...AND NEAR
90 IN THE WARMER MTN VALLEYS. HEAT INDEX VALUES SHOULD REMAIN BELOW
100 EVEN WITH THE SLIGHTLY HIGHER DEW POINTS. LOWS WILL BE UP TO 5
DEGREES ABOVE NORMAL.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AT 230 AM EDT WEDNESDAY...ON THURSDAY MORNING A LOW AMPLITUDE
UPPER RIDGE WILL BE OVER THE WEST AND A LOW AMPLITUDE TROUGH WILL BE
OVER THE EAST. MEANWHILE...A WELL DEFINED SHORTWAVE WILL CROSSING
THE MID MS RIVER VALLEY. THE UPPER PATTERN STARTS TO AMPLIFY ON
THURSDAY NIGHT...WHILE THE SHORTWAVE CROSSES THE SOUTHERN
APPALACHIANS. ON FRIDAY ANOTHER...WEAKER SHORTWAVE APPROACHES THE
MOUNTAINS...WHILE THE UPPER PATTERN CONTINUES TO AMPLIFY. THIS
SECOND SHORTWAVE MOVES INTO OUR AREA LATE FRIDAY NIGHT.

AT THE SURFACE...A SLOW MOVING COLD FRONT WILL BE OVER OUR AREA ON
THURSDAY MORNING. THE FRONT SLIDES SOUTH OF OUR AREA ON THURSDAY
EVENING...BUT MOISTURE LINGERING BEHIND IT SUBSTANTIALLY DECREASE
UNTIL LATE FRIDAY. MOISTURE EVEN INCREASES FRIDAY NIGHT AS THE
SECOND SHORTWAVE ARRIVES. MOISTURE AN INSTABILITY WILL BE
SUPPORTIVE OF CONVECTION...MAINLY DURING DAYTIME HEATING. INITIALLY
LOW LEVEL FLOW WILL BE SOUTHWESTERLY...AND NOT VERY FAVORABLE FOR
UPSLOPE FLOW...BUT AS THE SECOND SHORTWAVE ARRIVES IN THE WAKE OF
THE COLD FRONT...VEERING SURFACE WINDS WILL HAVE A WEAK UPSLOPE
COMPONENT INTO THE BLUE RIDGE. TEMPERATURES WILL RUN NEAR NORMAL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AT 230 AM EDT WEDNESDAY...ON SATURDAY MORNING AND UPPER RIDGE WILL
BE OVER THE PLAINS...WHILE A TROUGH WILL BE ALONG THE EAST COAST.
THE UPPER RIDGE BROADENS AND BUILDS EAST ACROSS THE GULF STATES AND
SOUTHERN APPALACHIANS BY SUNDAY...WHILE THE COASTAL TROUGH WEAKENS.
ON MONDAY THE UPPER RIDGE RETROGRESSES AND AMPLIFIES ALONG THE EAST
SLOPES OF THE ROCKIES...WHILE THE EASTERN TROUGH RETROGRESSES AND
AMPLIFIES OVER THE EASTERN USA.

AT THE SURFACE...A COLD FRONT WILL BE SOUTH OF OUR AREA ON SATURDAY
MORNING. DESPITE THE PASSAGE OF THE FRONT...TEMPERATURES WILL
ACTUALLY WARM IN ITS WAKE AS HEIGHTS RISE ALOFT. MOISTURE WILL
INCREASE OVER THE MOUNTAINS ON MONDAY AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WEAKENS AS IT ARRIVES ON MONDAY....BUT SUBSTANTIAL
MOISTURE ASSOCIATED WITH THE REMAINS OF THE BOUNDARY WILL CROSS OUR
AREA...WITH ENOUGH INSTABILITY TO SUPPORT CONVECTION. DESPITE THE
INCREASE IN MOISTURE...WIDESPREAD HEAVY RAIN APPEARS UNLIKELY AS LOW
LEVEL FLOW IS PARALLEL TO THE BLUE RIDGE...AND STEERING FLOW SHOULD
KEEP CELLS MOVING. BY LATE TUESDAY THE BULK OF THE MOISTURE APPEARS
TO MOVE EAST OF OUR AREA.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...VFR. CIRRUS RETURNS ACROSS THE AREA THIS MORNING WITH CU
DEVELOPING FOR THE AFTERNOON AND BECOMING BKN. EXPECT THE LIGHT NLY
WINDS THIS MORNING TO BECOME SWLY FOR THE AFTERNOON AS MIXING
DEVELOPS AND LOW LEVEL FLOW SLOWLY STRENGTHENS. THAT SAID...IT COULD
OCCUR A LITTLE EARLIER. AN UPPER LEVEL SHORT WAVE MOVING INTO THE
AREA TODAY WILL BRING A BETTER CHC OF LATE AFTERNOON AND EVENING
CONVECTION. HAVE GONE WITH A PROB30...WHICH CONTINUES AFTER MIDNIGHT
AS THE SHORT WAVE MOVES THRU LATER. WIND BECOMES LIGHT TOWARD
DAYBREAK AND COULD RETURN TO ENE. CONVECTIVE DEBRIS CLOUDS WILL
CONTINUE THRU THE NITE AS WELL.

ELSEWHERE...SIMILAR CONDITIONS TO KCLT...EXCEPT FOR EARLIER CHC OF
CONVECTION AT KAVL. IN ADDITION...WINDS AT KAVL WILL ONLY BRIEFLY BE
SLY LATE THIS MORNING AND EARLY AFTERNOON...WITH NNW THE REST OF THE
TIME. CONVECTION SHOULD ALSO END EARLIER AT THE SC SITES AS BEST
FORCING WILL BE ACROSS NC. CANNOT RULE OUT SOME SPOTTY FOG TOWARD
DAYBREAK IN THE NORMALLY MORE FOGGY AREAS...BUT CHC TOO LOW TO
INCLUDE ATTM.

OUTLOOK...GRADUALLY INCREASING PRECIPITATION/RESTRICTION CHANCES ARE
EXPECTED THROUGH LATE WEEK AS MOISTURE RETURNS...A FRONT STALLS IN
OUR VICINITY...AND AN UPPER WAVE MOVES THROUGH THU NIGHT. EXPECT
SOME DRYING LATE FRI INTO THE WEEKEND.

CONFIDENCE TABLE...

            10-16Z        16-22Z        22-04Z        04-06Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH 100%     HIGH 100%     HIGH  87%
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...JAT
NEAR TERM...RWH
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH


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