Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 261205
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
805 AM EDT TUE MAY 26 2015

.SYNOPSIS...
A BERMUDA HIGH PATTERN WILL PERSIST ACROSS THE SOUTHEAST STATES
THROUGH THE END OF THE WEEK. THIS WILL PRODUCE A MOIST SOUTHERLY
FLOW WITH INCREASED CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS
EACH DAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 AM...SHRA SCATTERING OUT...BUT LINGERING ACROSS THE MTNS.
EXPECT THE SHRA TO BECOME ISOLATED THRU THE MORNING...BUT LINGER
INTO THE AFTERNOON. STILL EXPECT BEST CHC OF CONVECTION TO DEVELOP
FROM WEST TO EAST DURING THE LATE AFTERNOON AND LINGER INTO THE
OVERNIGHT HOURS. FCST GENERALLY ON TRACK WITH UPDATES MAINLY FOR
CURRENT CONDITIONS.

AS OF 300 AM...SHORT WAVE CROSSING THE AREA THIS MORNING IS
COMBINING WITH THE MOIST UPSLOPE FLOW OVER THE AREA TO PRODUCE
SHOWERS AND ISOLATED TSRA ACROSS THE MTNS OF THE CAROLINAS AND NE
GA. THIS WAVE AND UPSLOPE FLOW WILL WEAKEN AFTER DAYBREAK BRINGING
AND END TO THE FORCING AND ALLOWING COVERAGE TO DIMINISH TO
ISOLATED. EXPECT QUITE A BIT OF CLOUDINESS TO CONTINUE ACROSS THE
AREA THIS MORNING EVEN OUTSIDE OF PRECIP WITH THE MOIST UPSLOPE
FLOW. SKIES MAY BRIEFLY SCATTER CONVECTIVE CU DEVELOPS AND BRINGS
WIDESPREAD CLOUDS BACK OVER THE AREA. CONVECTION WILL RETURN FROM
THE WEST LATE IN THE AFTERNOON AND SPREAD ACROSS THE CWFA. THE
CONVECTION WILL CONTINUE WELL INTO THE NITE AS ANOTHER SHORT WAVE
AND QUITE A BIT OF UPPER DIVERGENCE MOVE INTO THE AREA...ESPECIALLY
WRN SECTIONS. THE CONVECTION ALLOWING GUIDANCE IS IN GOOD AGREEMENT
ON THESE TRENDS...SO HAVE TRIED TO FOLLOW THIS IN THE GRIDS. BEST
INSTABILITY DEVELOPS DURING THE EARLY EVENING...AND MAINLY ALOFT
WHEN MID LEVEL TEMPS COOL AS THE SHORT WAVE MOVES IN. MODERATE
INSTABILITY AND SHEAR DEVELOP...SO CANNOT RULE OUT A SEVERE STORM OR
TWO...BUT THEY SHUD REMAIN ISOLATED. LOOKS TO BE A BETTER CHC OF
HEAVY RAIN AS PW VALUES INCREASE TO 1.5 STANDARD DEVIATIONS ABOVE
NORMAL. MBE VELOCITY VECTORS ARE ALSO SHORT INDICATING SLOW MOVING
STORMS. THERE COULD BE QUITE A BIT OF TRAINING ECHOES AS WELL WHICH
COULD ALLOW PRECIP AMOUNTS TO QUICKLY MOUNT. THAT SAID...CHC IS LOW
ENUF AND UNCERTAINTY HIGH ENUF TO PRECLUDE ANY FLOOD WATCHES ATTM...
BUT HEAVY RAIN WOULD LIKELY FAVOR THE WRN CWFA. HIGHS TODAY WILL BE
NEAR NORMAL WEST AND A LITTLE ABOVE NORMAL EAST. LOWS TONIGHT AROUND
10 DEGREES ABOVE NORMAL.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 245 AM TUESDAY...THE FCST ON WEDNESDAY MAY BE TRICKY...AS
MODELS HAVE CONVERGED ON NUMEROUS SHWRS AND TSTMS OVERNIGHT TUESDAY
NIGHT...LEAVING PLENTY OF CLOUD COVER OVER THE AREA THAT MAY LIMIT
RECOVERY FOR DIURNAL CONVECTION WED AFTN. NEVERTHELESS...GIVEN THE
VERY MOIST AIR MASS IN PLACE...EVEN A BRIEF BREAK IN THE CLOUDS SHUD
BE ENUF FOR ANOTHER ROUND OF CONVECTION...AS MODEL CONSENSUS SHOWS.
SO WILL ADVERTISE LIKELY TO CATEGORY POP ACRS MOST OF THE
CWFA...LOWEST EAST OF I-77 AND HIGHEST IN THE NC MTNS. TEMPS WILL
HELD IN THE 70S TO LWR 80S (AT OR BELOW NORMAL)...UNDER THE CLOUDS
AND PRECIP. POPS REMAIN ELEVATED OVERNIGHT WEDNESDAY NIGHT WITH
TEMPS WELL ABOVE NORMAL. WITH PWATS STILL VERY HIGH...SOME POTENTIAL
FOR SLOW-MOVING STORMS...THERE WILL BE AN ISOLD HEAVY RAIN THREAT.

ON THURSDAY...A SHORTWAVE TROF WILL GET SHEARED OUT AS IT TRIES TO
BREAK DOWN THE WESTERN EDGE OF THE LARGE ATLANTIC RIDGE. THE FLOW
THRU THE COLUMN WILL BE VERY WEAK AND PROFILES REMAIN MOIST. SO
EXPECT ANOTHER ROUND OF SHWRS AND TSTMS THURSDAY AFTN...WITH
SLOW-MOVING HEAVY RAIN PRODUCERS STILL THE PRIMARY THREAT. STORMS
SHUD WANE WITH LOSS OF HEATING. TEMPS WILL REMAIN NEAR NORMAL FOR
HIGHS AND SEVERAL CATEGORIES ABOVE NORMAL FOR LOWS.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...MODELS IN GOOD AGREEMENT THAT THE UPPER RIDGE
REASSERTS ITSELF SOMEWHAT BACK INTO THE SOUTHEAST STATES FOR FRIDAY
THRU THE WEEKEND. THE RESULT WILL BE A SUMMER-LIKE PATTERN OF
DIURNALLY-DRIVEN ISOLATED TO SCATTERED CONVECTION EACH DAY WITH
ABOVE NORMAL TEMPS. POPS INCREASE BACK TO HIGH-END CHC TO LIKELY ON
MONDAY...AS A DEEP SHORTWAVE TROF PUSHES INTO THE TN
VALLEY...INCREASING INSTBY AND MOISTURE INTO THE REGION.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AT KCLT...SURROUNDING SITES ARE MVFR AND EXPECT MVFR...AND POSSIBLY
TEMPO IFR...THERE AS WELL THIS MORNING. SHUD LIFT TO LOW VFR BY NOON
AND MAY EVEN SCATTER OUT BRIEFLY BEFORE CONVECTIVE CU RETURN FOR THE
AFTERNOON. GUIDANCE CONTINUES TO PUSH BEST CHC FOR CONVECTION OFF
INTO THE EVENING...SO HAVE TRENDED PROB30 THAT WAY AS WELL. SHUD BE
ANOTHER NIGHT WITH MVFR THEN IFR CIGS AS SLY FLOW AND LOW LEVEL
MOISTURE CONTINUE. WINDS REMAIN SLY THRU THE PERIOD.

ELSEWHERE... SIMILAR TO KCLT...EXCEPT THAT RESTRICTIONS ARE ALREADY
IN PLACE...AND SHRA WILL BE MORE LIKELY AT KAVL. AFTERNOON
CONVECTION ALSO LIKELY TO START EARLIER...BUT STILL SHUD HOLD OFF
UNTIL LATE AFTERNOON. RESTRICTIONS RETURN OVERNIGHT WITH CONVECTION
LINGERING THRU THE NITE. SLY WINDS THRU THE PERIOD.

OUTLOOK...S TO SW FLOW MOISTURE WILL CONTINUE TO STREAM ACROSS THE
TERMINAL FORECAST AREA THROUGH THE WEEK. EXPECT INCREASED MORNING
STRATUS TO RESULT...WITH BETTER THAN CLIMATOLOGICAL CHANCES OF
AFTN/EVENING SHRA/TSRA EACH DAY. HOWEVER...PASSING UPPER LEVEL
DISTURBANCES COULD GENERATE A FEW TSTMS AT OTHER TIMES OF THE DAY.

CONFIDENCE TABLE...

            12-18Z        18-24Z        00-06Z        06-12Z
KCLT       HIGH  93%     HIGH 100%     HIGH 100%     HIGH  84%
KGSP       HIGH  98%     HIGH  96%     HIGH  98%     HIGH  90%
KAVL       HIGH  89%     HIGH  95%     HIGH  96%     HIGH  88%
KHKY       HIGH  85%     HIGH 100%     HIGH  94%     HIGH  87%
KGMU       HIGH  94%     HIGH  96%     HIGH  98%     HIGH  88%
KAND       HIGH  94%     HIGH  95%     HIGH 100%     MED   75%

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...RWH
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...RWH



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