Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 020512
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
112 AM EDT MON MAY 2 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST AN KEEP A WARM AND HUMID
AIR MASS ACROSS THE SOUTHEAST REGION THROUGH MONDAY. THIS FRONT WILL
SLOWLY PUSH EAST OF THE AREA ON TUESDAY. ANOTHER COLD FRONT WILL
CROSS THE AREA ON THURSDAY AND BRING COOLER CANADIAN AIR PERSISTING
INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1 AM MONDAY MORNING...AREA OF SHOWERS AND THUNDERSTORMS WILL
SHORTLY EXIT THE CWA EASTWARD WITH ONLY WIDELY SCATTERED SHOWERS
UPSTREAM.  PER CAM MODEL GUIDANCE...THUNDERSTORMS ARE NOT EXPECTED
UNTIL REDEVELOPMENT/INITIATION MONDAY AFTERNOON IN AN ENVIRONMENT
SIMILAR TO THE LAST 2 DAYS WITH CAPE OF AROUND 1000 J/KG AND DEEP
LAYER SHEAR OF 20 TO 35 KTS. HOWEVER...A FEW WIDELY SCATTERED
SHOWERS ARE ANTICIPATED BEFORE THEN. CURRENT PATTERN OF CONVECTIVE
ACTIVITY WITH SOUTHWESTERLY SURFACE FLOW MAINTAINING BL MOISTURE
WITH FORCING FROM A LARGE UPPER TROUGH OVER THE CENTRAL CONUS WILL
CONTINUE THROUGH MONDAY.  WARM ADVECTION PATTERN WILL KEEP AFTERNOON
HIGHS TOMORROW 5 TO 10 DEGREES ABOVE NORMAL WITH RELATIVELY HIGH RH.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT SUNDAY...THE BROAD MODEL CONSENSUS DOES NOT LEAD TO
MUCH CHANGE TO THE GOING THINKING WITH RESPECT TO THE EXPECTED
SENSIBLE WEATHER FOR TUESDAY.  UPPER LEVEL HEIGHTS ATOP THE SE CONUS
WILL CONTINUE THEIR STEADY LOWERING AND A BROAD WSW FLOW THROUGH A
DEEP LAYER REMAINS. DESPITE THE LACK OF ANY LARGER SCALE FORCING...
SCATTERED DIURNAL ENHANCED TSTMS ARE STILL PROBABLE. THE UPPER
PATTERN CONTINUES TO AMPLIFY ON WEDNESDAY BUT THE LOWER LEVEL
BAROCLINIC ZONE IS PROGGED TO TRANSLATE DOWNSTREAM OF THE CWFA
LEAVING US IN A RELATIVE LULL. ENERGY DUMBBELLING AROUND DEEPENING
UPPER LOW MAY RESULT IN MTN SHOWERS BY WED NITE.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 140 PM SUNDAY...GOOD CONFIDENCE IS HAD IN THE EXT RANGE FCST
AS THE OP MODELS ARE SHOWING GOOD AGREEMENT WITH THE ULVL PATTERN
AND THE SENSIBLE WX RESPONSE. THE GEFS MEMBERS ARE SHOWING LITTLE
SPREAD OVER THE ERN CONUS UNTIL LATE FRIDAY...MAINLY DUE TO DEEPNESS
DIFS WITH THE UPPER LOW.

THE PATTERN STILL SUGGESTS A DEVELOPING OMEGA BLOCK WITH THE ERN LOW
DEEPENING AND DROPPING SE OFF THE ATL COAST INTO THE SAT TIME
FRAME...THEN QUICKLY RISING HEIGHTS THROUGH THE REMAINDER OF THE
PERIOD. A COLD FRONT WILL BRING A SHOT OF LLVL MOISTURE TO THE FAR
WRN MTNS EARLY THU...WHICH WILL QUICKLY WANE AFTER SUNRISE. NOT
EXPECTING MUCH QPF RESPONSE FROM THIS FEATURE. THINGS WILL REMAIN
RATHER DRY AFTER THAT AS DEEP NW FLOW ENGULFS THE REGION AND A
REINFORCING SHOT OF LOW THETA/E AIR MIXES IN. THERE ARE SOME
DIFFERENCES FRI BTW THE OP MODELS WITH AN EMBEDDED S/W CREATING
SHOWERS ACROSS THE NRN ZONES...BUT GIVEN THE LARGE SCALE PATTERN AM
NOT ANTICIPATING MUCH MEASURABLE PRECIP WITH THIS SITUATION EITHER.
THE ATMOS WILL REMAIN RATHER STABLE THROUGH THE PERIOD...SO NO
THUNDER WILL BE INCLUDED IN THE GRIDS. OVERALL...THE PERIOD LOOKS TO
PRETTY NICE FOR EARLY MAY WITH MOSTLY DRY CONDS...MID/UPPER LEVEL
CLOUDS AND PLEASANT TEMPS. BELOW NORMAL HIGHS BY A CAT OR SO ARE
EXPECTED THU THRU SAT...THEN ABOVE NORMAL TEMPS PROBABLE BY SUN AS
UPPER RIDGE AXIS NEARS AND DEEP SUBS INCREASES.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...THUNDER MAY PERSIST WELL INTO THE
EVENING...WITH SOME MODELS EVEN SUGGESTING AN INCREASE AROUND
MIDNIGHT. GUIDANCE HAD VARIED ON DAYBREAK VSBY RESTRICTIONS, BUT THE
BEST BET APPEARS TO BE AT MOUNTAIN AND FOOTHILL SITES, WITH VFR AT
KCLT. CEILING ARE EXPECTED TO FALL TO MVFR BY DAWN AT SC SITES AND
BRIEFLY IFR AT KCLT. BLENDED GUIDANCE SUPPORTS LOW VFR DAYBREAK CIGS
AT KAVL AND KHKY, BUT SCATTERED LOW DECK CLOUDS WILL BE CARRIED AS WELL.
IMPROVEMENT TO VFR IS EXPECTED AFTER DAWN. THUNDER CHANCES, THOUGH
NEVER ZERO, WILL INCREASE AGAIN WITH HEATING AFTER DAWN, ESPECIALLY
IN THE MOUNTAINS. WINDS WILL GENERALLY FAVOR THE SSW.

OUTLOOK...UNSETTLED WEATHER/OCCASIONAL CONVECTION/RESTRICTIONS ARE
EXPECTED TO CONTINUE THROUGH ABOUT TUESDAY. DRYING IS EXPECTED BY
WEDNESDAY...AND THE DRY WEATHER SHOULD PERSIST THROUGH THE END OF
THE WEEK.

CONFIDENCE TABLE...

            05-11Z        11-17Z        17-23Z        23-00Z
KCLT       HIGH 100%     MED   72%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH  94%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     MED   61%     HIGH 100%     HIGH 100%
KHKY       LOW   57%     HIGH  83%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH  83%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     MED   72%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY.  COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:

WWW.WEATHER.GOV/GSP/AVIATION

&&

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

&&

$$
SYNOPSIS...SBK
NEAR TERM...WJM
SHORT TERM...CSH
LONG TERM...SBK
AVIATION...JAT



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