Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 210731
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
331 AM EDT TUE APR 21 2015

.SYNOPSIS...
DRY HIGH PRESSURE BUILDS IN TODAY...THEN SLIDES EAST OF THE AREA
WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM...AN UPPER LOW WILL CONTINUE TO SPIN NEARLY STATIONARY
OVER THE NORTHERN GREAT LAKES...WITH THE SOUTHERN EDGE OF THE
CIRCULATION OVER THE SOUTHERN APPALACHIANS. A MODEST SFC HIGH WILL
SLIDE IN FROM THE NW UNDER THE CONFLUENT FLOW ALOFT...RESULTING IN A
PLEASANT DAY IN STORE FOR THE AREA. IT SHUD BE DRY TODAY THRU
TONIGHT...WITH A FEW CU AND THIN CIRRUS THIS AFTN. TEMPS WILL BE
ABOUT A CATEGORY BELOW NORMAL WITH HIGHS IN THE 60S IN THE MTNS TO
LWR 70S ALONG AND SOUTH OF I-85. LOWS TONIGHT IN THE UPR 30S TO LWR
40S IN THE MTNS AND MAINLY MID 40S TO AROUND 50 IN THE PIEDMONT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 210 AM TUESDAY...A BROAD LOW AMPLITUDE TROF STARTS OVER THE
ERN CONUS ON WED. A SERIES OF SHORT WAVES WILL ROTATE THRU THE TROF
AND ACROSS THE AREA THRU THU. THE TROF AXIS THEN SLIDES EAST THU
NITE WITH NW FLOW SETTING UP AS RIDGING BUILDS INTO THE SRN PLAINS.
AT THE SFC...A COLD FRONT CROSSES THE AREA FROM THE NW ON WED THEN
MOVES SOUTH OF THE AREA WED NITE. THE GUIDANCE AGREES THAT THERE
WILL BE ENUF MOISTURE AND FORCING WITH THE FRONT FOR SCT SHRA ACROSS
THE MTNS AND ISOLATED SHRA ELSEWHERE. HOWEVER...THE GUIDANCE THEN
DIFFERS WITH THE GFS STALLING THE FRONT JUST SOUTH OF THE CWFA
KEEPING DRY HIGH PRESSURE AT BAY. MOISTURE THEN SLIDES BACK INTO THE
AREA FROM THE WEST ON THU...BRINGING ANOTHER ROUND OF PRECIP. THE
REST OF THE MDLS SHOW THE FRONT MOVING FARTHER SOUTH ALLOWING THE
DRY HIGH PRESSURE TO BUILD IN FROM THE NORTH. HAVE TRENDED TOWARD
THE DRIER GUIDANCE...BUT DO KEEP SOME LINGERING ISOLATED SHRA THU
MORNING. DRY FCST CONTINUES THU NITE. HIGHS WILL BE NEAR NORMAL
AHEAD OF THE FRONT WED...THEN FALLS TO AROUND 5 DEGREES BELOW NORMAL
THU. LOWS FOLLOW A SIMILAR TREND...WITH LOWS AROUND 5 DEGREES ABOVE
NORMAL WED NITE...THEN FALL TO NEAR OR JUST BELOW NORMAL THU NITE.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 325 AM TUESDAY...GUIDANCE IN GOOD AGREEMENT EARLY IN THE FCST
BUT DIVERGE SOMEWHAT BY THE END. SHORT WAVE RIDGING FRI GIVES WAY AS
A DAMPENING SHORT WAVE CROSSES THE AREA SAT AND MOVES EAST OF THE
AREA SUNDAY. AT THE SFC...DRY HIGH PRESSURE FRI GIVES WAY TO A
COMPLEX STORM SYSTEM MOVING THRU SAT THEN EAST OF THE AREA SUN.
HIGHS FRI AROUND 5 DEGREES BELOW NORMAL COOL SEVERAL DEGREES ON SAT
WITH PRECIP MOVING IN AND SOME FORM OF COLD AIR DAMMING DEVELOPING.
HIGHS RISE A FEW DEGREES ON SUN WITH PRECIP ENDING. LOWS AROUND 5
DEGREES ABOVE NORMAL COOL TO NEAR NORMAL. SHORT WAVE ENERGY MOVES
TOWARD THE AREA MONDAY THEN ACROSS THE AREA TUESDAY. THE GFS KEEPS
THE WAVE OPEN AND WEAKER WHILE THE ECMWF CLOSES OFF AN UPPER LOW AND
BRINGS IT SOUTH TOWARD THE AREA AS STRONGER SHORT WAVES ROTATE
AROUND THE LOW AND ACROSS THE AREA. AT THE SFC...THE GFS HAS DRY
HIGH PRESSURE FOR MONDAY WITH A CLIPPER TYPE SYSTEM APPROACHING FROM
THE NW. THE ECMWF HAS DRY HIGH PRESSURE OVER THE AREA MON MORNING
WITH A STRONGER AND DEEPER SFC LOW APPROACHING FROM THE WEST. GIVEN
THE UNCERTAINTY HAVE GONE WITH A MDL BLEND WHICH BRINGS IN LOW
PRECIP CHC FROM THE WEST LATE IN THE DAY. TEMPS WILL BE NEAR TO 5
DEGREES BELOW NORMAL.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AT KCLT AND ELSEWHERE...MUCH QUIETER WX FOR THE NEXT 24 HOURS...AS
DRY HIGH PRES BUILDS IN BEHIND A DEPARTING COLD FRONT. THE MAIN
CONCERN WILL BE WINDS...WITH GUIDANCE SHOWING LLVL FLOW OUT OF THE
WEST-NORTHWEST...WHILE A LEE TROF WILL SET UP AGAIN THIS
AFTN...BACKING WINDS TO SW. A FEW LOW-END GUSTS ARE EXPECTED
STARTING AROUND MIDDAY...THEN ENDING AROUND SUNSET. THERE MAY BE
ENUF MOISTURE AT TOP OF MIXED LAYER FOR FEW-SCT VFR LVL CUMULUS THIS
AFTN...ESP AT KCLT AND KHKY WITH BASES AROUND 5000 FT. DESPITE WET
SOILS FROM LAST FEW DAYS OF RAIN...EXPECT ENUF LINGERING WIND AND
DROPPING SFC DEWPTS TO LIMIT FOG POTENTIAL THIS MORNING.

OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON WEDNESDAY...WITH A
LITTLE MOISTURE. NOT EXPECTING MUCH LOW CLOUDS OR PRECIP WITH THE
FROPA. THEN ANOTHER DRY HIGH PRES SYSTEM BUILDS IN THURSDAY THRU
FRIDAY...BEFORE ANOTHER WET STORM SYSTEM IS EXPECTED TO APPROACH THE
AREA FROM THE WEST ON SATURDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
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...ARK
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK


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