Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 261510
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1110 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 1100 AM EDT...SCATTERED SHOWERS CONTINUE TO TRIGGER IN UPSLOPE
SECTIONS OF THE SRN MOUNTAINS LATE THIS MORNING...BUT THE RADAR IS
QUIET ACROSS THE REST OF THE CWFA. ATTENTION IS TURNING BACK TO THE
WEST WHERE CONVECTIVE TRIGGERING ON REMNANT OUTFLOWS IS OCCURRING
ACROSS CENTRAL AL AND ADDITIONAL COVERAGE WILL LIKELY DEVELOP ALONG
THE AL/GA LINE THROUGH THE AFTN HOURS. THE CONVECTION ALLOWING
MODELS INSIST ON THIS LATER DEVELOPMENT MAKING A RUN E/NE TOWARD THE
FORECAST AREA EARLY THIS EVENING...REACHING NE GA 22Z TO
00Z...CROSSING THE UPSTATE OF SC AND PORTIONS OF WRN NC THIS
EVENING...AND THEN GENERALLY DISSIPATING OVER OR NEAR CLT LATE
EVENING/EARLY OVERNIGHT. THIS PRESENTATION SEEMS VERY REASONABLE
GIVEN THE CURRENT ACTIVITY...SBCAPE VALUES ON THE LAPS ANALYSIS
ACROSS GA...AND STEERING FLOW. POPS AND HAVE BEEN TWEAKED
ACCORDINGLY.

OTHERWISE...THE INSTABILITY CONTINUES TO LOOK LIMITED FOR ANY STRONG
TO SEVERE CONVECTION...WITH A MARGINAL WIND THREAT WITH ANY COLD
POOLS DEVELOPING UPSTREAM POSING THE MAIN CONCERN IN SW SECTIONS
THROUGH MID EVENING. PRECIPITABLE WATER VALUES WILL CONTINUE TO
INCREASE AND ANY TRAINING OF CELLS WILL BE THE PRIMARY CONCERN FOR
ISOLD HYDRO ISSUES...ESPECIALLY IN THE SRN MTNS. LOWS TONIGHT WILL
BE AROUND 10 DEGREES ABOVE NORMAL GIVEN THE MOIST BOUNDARY LAYER AND
REDEVELOPING LOWER STRATUS.

&&

.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 /15Z TUESDAY THROUGH SATURDAY/...
AT KCLT...LIFTING AND SCATTERING OF THE MVFR CLOUDS HAS
CONTINUED...AND ANY CIGS GOING FORWARD FROM HEATING SHOULD BE AT
LOWER VFR LEVELS AS CCL HEIGHTS SLOWLY RISE. THERMAL PROFILES REMAIN
FAIRLY CAPPED...AND ANY CONVECTION MAKING A RUN AT THE AIRFIELD
WOULD HAVE TO APPROACH LATE EVENING WITH THE ACTIVITY PUSHING NE
FROM GA. THIS IS NOT EXPECTED TO REACH KCLT AT PRESENT BEFORE
DISSIPATING...BUT A PROB30 STILL SEEMS WARRANTED AFTER 03Z. MVFR
CIGS LOOKS LIKELY OVERNIGHT IN THE CONTINUED MOIST BL...WITH IFR
CIGS POSSIBLE TOWARD DAYBREAK. WINDS REMAIN SLY THROUGH THE PERIOD.

ELSEWHERE...RESTRICTIONS HAVE GENERALLY LIFTED TO LOWER END VFR
EXCEPT FOR PESKY STUBBORN STRATUS IN THE FRENCH BROAD VALLEY NEAR
KAVL. LITTLE IN THE WAY OF ANY SHRA/TSRA ACTIVITY IS EXPECTED
THROUGH THE AFTN HOURS...UNTIL UPSTREAM CONVECTION NEAR THE GA/AL
BORDER BEGINS TO MAKE A RUN NE TOWARD EVENING. WILL KEEP VFR CIGS AT
THE CCL THROUGH THE LATE DAY...WITH GENERALLY PROB30 THROUGH THE
EVENING/EARLY OVERNIGHT FOR ARRIVING TSRA. SFC WINDS WILL REMAIN S
TO SW AT 10 KT OR LESS THROUGH THE PERIOD. ANOTHER ROUND OF MVFR
CLOUDS IS LIKELY OVERNIGHT INTO WED MORNING WITH THE MOIST BL...WITH
TEMPO IFR POSSIBLE AT TIMES TOWARD DAYBREAK...ESPECIALLY NEAR
LOCATIONS WHERE RAIN FALLS.

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...

            15-21Z        21-03Z        03-09Z        09-12Z
KCLT       HIGH  98%     HIGH 100%     HIGH 100%     HIGH  80%
KGSP       HIGH  96%     HIGH 100%     HIGH 100%     HIGH  82%
KAVL       HIGH  85%     HIGH  98%     HIGH  89%     HIGH  95%
KHKY       HIGH  87%     HIGH 100%     HIGH  87%     MED   71%
KGMU       HIGH  94%     HIGH 100%     HIGH 100%     HIGH  82%
KAND       HIGH  87%     HIGH 100%     HIGH  98%     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
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...HG


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