« Back
NWS Peachtree City, Ga » Text Product » GSP Area Forecast Discussion


Printer-friendly Version
Current Version              Previous Versions:   1  2  3  4  5  6  7  8  9  

Area Forecast Discussion

843
FXUS62 KGSP 261344
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
944 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 945 AM...THE MAIN ADJUSTMENT TO THE GOING FORECAST HAS BEEN TO
BOOST POPS IN THE SRN MOUNTAINS IN LINE WITH THE LATEST CONVECTION
ALLOWING MODEL GUIDANCE. THIS WILL PERMIT SOLID CHC TO LOW LIKELY
FOR A COUPLE OF HOURS IN THE SRLY UPSLOPE SECTIONS...THEN CHC
SHRA/TSRA ACROSS THE HIGHER TERRAIN THROUGH THE AFTN HOURS.
TEMPERATURES ARE IN LINE WITH THE FORECAST AS CLOUD COVER IS
INHIBITING INSOLATION IN MOST AREAS.

OTHERWISE...COVERAGE SHOULD DIMINISH A BIT AS THE PASSING UPPER
SUPPORT LIFTS AWAY LATE MORNING INTO THE EARLY AFTN. EXPECT QUITE A
BIT OF CLOUDINESS TO CONTINUE ACROSS THE AREA. SKIES MAY BRIEFLY
SCATTER UNTIL 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 /14Z TUESDAY THROUGH SATURDAY/...
AT KCLT...LIFTING AND SCATTERING HAS STARTED A BIT EARLIER THAN
FORECAST...MAINLY ALONG THE EAST SIDE OF THE AIRFIELD. STILL SEEING
SOME MVFR CIGS TO THE WEST AND TEMPO MVFR THROUGH 16Z IS
APPROPRIATE. ANTCIPATE LOWER CLOUDS LIFTING TO VFR AROUND NOON WITH
ANY AFTN CIGS FORMING MAINLY NEAR THE CCL. GUIDANCE CONTINUES TO
PUSH BEST CHC FOR CONVECTION OFF INTO THE EVENING...SO HAVE TRENDED
PROB30 THAT WAY AS WELL. SHOULD BE ANOTHER NIGHT WITH MVFR THEN IFR
CIGS AS SLY FLOW AND LOW LEVEL MOISTURE CONTINUE. WINDS REMAIN SLY
THRU THE PERIOD.

ELSEWHERE...RESTRICTIONS ARE STARTING TO LIFT IN MOST PLACES BUT
WITH TEMPO MVFR CIGS STILL LIKELY AT TIMES ACROSS THE MTNS AND
FOOTHILLS THROUGH LATE MORNING. SHRA WILL BE MORE LIKELY AT KAVL
THIS MORNING. 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...

            13-19Z        19-01Z        01-07Z        07-12Z
KCLT       HIGH  91%     HIGH 100%     HIGH 100%     HIGH  83%
KGSP       HIGH  95%     HIGH  97%     HIGH  98%     HIGH  93%
KAVL       HIGH  87%     HIGH  95%     HIGH  95%     HIGH  91%
KHKY       HIGH  86%     HIGH 100%     HIGH  93%     HIGH  85%
KGMU       HIGH  97%     HIGH  97%     HIGH  98%     HIGH  91%
KAND       HIGH  94%     HIGH  97%     HIGH 100%     MED   73%

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...HG/RWH
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...HG/RWH



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.