000
FXUS62 KGSP 191927
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
327 PM EDT WED JUN 19 2013

.SYNOPSIS...
COOLER HIGH PRESSURE CENTERED NEAR NEW YORK STATE WILL RIDGE
SOUTHWARD TONIGHT AND THURSDAY. THIS HIGH WILL DRIFT TO NEAR BERMUDA
AND INTO NEXT WEEK AS AN UPPER RIDGE BUILDS IN FROM THE WEST AS
TEMPERATURES SLOWLY RISE.

&&

.NEAR TERM /THROUGH THURSDAY/...
1930 UTC UPDATE...SKY COVER HAS BEEN UPDATED FROM THE LATEST VISIBLE
SATELLITE IMAGERY. POPS WERE RAISED IN THE THE NORTHERN NC
MOUNTAINS...AND THE UPPER SAVANNAH RIVER VALLEY...PER RADAR TRENDS.

AS OF 215 PM...A WEAK SHORT WAVE TROUGH IS FORECAST TO MOVE THROUGH
THE AREA FROM NW TO SE LATE THIS AFTERNOON AND EARLY TONIGHT. THE
BEST FORCING WILL BE OVER THE FAR EASTERN AREAS. HENCE...THE MODELS
SHOW SOME LIGHT QPF RESPONSE THERE. THE LATEST HRRR SHOWS THE MOST
SHOWER COVERAGE FROM THE NORTHERN MOUNTAINS...EAST THROUGH THE
NORTHERN NC PIEDMONT. WILL MAKE A LAST MINUTE ADJUSTMENT ON THE POP
FIELD TO REFLECT THAT IDEA. WIDELY SCT SHOWERS/THUNDERSTORMS ARE
EXPECTED ELSEWHERE THROUGH THE MOUNTAINS DURING THE MID TO LATE
AFTERNOON HOURS DUE TO WEAK UPSLOPE FLOW. CAPES SHOULD GENERALLY
STAY BELOW 1000J AS SOMEWHAT LOWER DEWPOINTS CONTINUE TO ADVECT INTO
THE REGION...SO NO SEVERE THREAT. THE SHOWERS ARE EXPECTED TO
DISSIPATE DURING EVENING.

OTHERWISE...THE OVERNIGHT SHOULD BE QUIET. MODEL TIME HEIGHTS SHOW
LOW LEVEL MOISTURE INCREASING TOWARD SUNRISE AS MOISTURE FROM
ATLANTIC ADVECTS INTO THE AREA. THEREFORE...EXPECT A PERIOD OF LOW
CLOUDINESS EARLY THU...ESPECIALLY EAST OF I-26. ON THU...HIGH
PRESSURE LOCATED OFF THE NEW ENGLAND COAST WILL REMAIN RIDGED INTO
THE AREA PRODUCING AN EASTERLY WIND FLOW IN THE SOUTHERN
APPALACHIANS. THE UPSLOPE FLOW IN THE MOUNTAINS SHOULD PRODUCE
SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON HOURS.
USING A BLEND OF MODELS PRODUCES MAX TEMPS ABOUT A CATEGORY BELOW
AVERAGE ON THU.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 210 PM EDT WED...SHORT RANGE MODELS AGREE THAT THE REGION WILL
REMAIN UNDER A WEAK MID LEVEL TROUGH...WITH RIDGING ACROSS THE
SOUTHERN PLAINS AND ATLANTIC. AT THE SFC...A STATIONARY FRONT AND
POSSIBLE FRONTAL WAVE WILL REMAIN ACROSS THE COASTAL PLAIN OF THE
CAROLINAS. WEAK SFC RIDGING MAY REMAIN ACROSS THE SOUTHERN
APPALACHIAN REGION. GIVEN THE SFC PATTERN...I WILL INDICATE
PERSISTENT NE WINDS ACROSS THE FOOTHILLS AND PIEDMONT FOR FRIDAY AND
SATURDAY. A BLEND OF MODEL GUIDANCE INDICATES THAT SKY COVER WILL
REMAIN PARTLY TO MOSTLY CLOUDY THROUGH THE PERIOD. THE COMBINATION
OF NE WINDS AND CLOUD COVER SHOULD YIELD TEMPERATURES 3 TO 5 DEGREES
BELOW NORMAL. OVERALL...THE CHCS OF SHRA AND TSRA APPEARS
UNFAVORABLE WITHIN THE CORRIDOR OF DEEP NE FLOW. IN FACT...MODEL
CAPE FIELDS INDICATE LITTLE TO NO VALUES FOR SFC BASED PARCELS
BETWEEN THE EAST FACING MTN SLOPES TO THE WESTERN PIEDMONT. I WILL
INDICATE SCHC POPS FOR TS ACROSS THE EXTREME WESTERN NC MTNS ON FRI
AND SAT. BY SAT...LLVL WINDS MAY VEER NE...POSSIBLY ALLOWING WEAK
INSTABILITY ACROSS NE GA AND THE EASTERN PIEDMONT DURING THE LATE
AFTERNOON.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 240 PM EDT WED...A 591 DM H5 RIDGE WILL REMAIN DOMINANT OVER
THE SE THROUGH THE MEDIUM RANGE PERIOD. ANTICIPATE A MAINLY DIURNAL
TREND OF ISOLD TO SCATTERED AFTERNOON POPS THROUGH THE PERIOD...WITH
THE MTNS BEING THE PRIMARY FOCUS. THE GFS IS THE MOST AGGRESSIVE IN
BRINGING AN INVERTED COASTAL TROUGH BACK INLAND ALONG THE SAVANNAH
ON SATURDAY...BUT THE OTHER OPERATIONAL AND ENSEMBLE MEAN SOLUTIONS
KEEP THE SYSTEM ALONG THE IMMEDIATE COAST WITH THE RIDGE PERSISTING
OVER THE WRN CAROLINAS. THE DIURNAL PATTERN OF ISOLD TO SCT SHOWERS
AND THUNDERSTORMS SHOULD THUS CONTINUE SUN THROUGH TUE...WITH
TEMPERATURES STEADILY WARMING UNDER THE UPPER RIDGE. EXPECT MAXES TO
REACH CLIMATE NORMALS BY SUNDAY AND THEN EXCEED THEM MON AND TUE.
THE UPPER RIDGE WILL BREAK DOWN IN MID WEEK AS A UPPER TROUGH FORMS
OVER THE EAST COAST FOR THE SECOND HALF OF NEXT WEEK. THE GFS IS A
BIT MORE PROGRESSIVE IN BRINGING THE TROUGH IN SOONER BY LATE WED OR
WED NIGHT AS OPPOSED TO THUR OR FRI ON THE ECMWF. TEMPS ARE EXPECTED
TO COOL SOME AS THIS TROUGH SETS UP WITH MORE CLOUDS AND HIGHER POPS.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...SCT-BKN CU IS EXPECTED THROUGH THE AFTERNOON. CONVECTIVE
CHANCES STILL SEEM TOO LOW TO MENTION IN THE TAF. SOME SHRA
ASSOCIATED WITH A WEAK BACKDOOR FRONT WILL PROBABLY BE NOTED ON
RADAR WELL TO THE NORTH OF THE FIELD LATE THIS AFTERNOON. MOST
GUIDANCE SUGGESTS THAT STRATUS WILL ARRIVE FROM THE E-NE LATE
TONIGHT. HENCE...HAVE INTRODCUED A BKN016 BEGINNING AT 11Z. THE
STRATUS SHOULD THEN SCT BY 15Z.

ELSEWHERE...IT APPEARS CONVECTIVE CHANCES WILL BE MOSTLY LIMITED TO
WIDELY SCATTERED SHOWERS/THUDNERSTORMS OVER THE MOUNTAINS AND NC
FOOTHILLS. HOWEVER...CHANCES TOO LOW TO MENTION EXCEPT FOR A VCSH AT
KAVL LATE THIS AFTERNOON. BKN VFR CU WILL SCT THIS EVENING. GUIDANCE
IS ADVERTISING A STRATUS DECK TO ARRIVE FROM THE E-NE LATE TONIGHT
AND IS EXPECTED TO AFFECT ALL AIRFIELDS WITH AT LEAST MVFR CIGS FOR
SEVERAL HOURS EARLY THU...EXCEPT KAND.

OUTLOOK...INCREASING MOISTURE TOWARDS THE END OF THE WORK WEEK WILL
ALLOW DIURNAL CONVECTION TO DEVELOP EACH AFTERNOON....MAINLY OVER
THE MOUNTAINS. GENRALLY VFR CONDITIONS ARE EXPECTED EXCEPT SOME
EARLY MORNING STRATUS IS POSSIBLE EACH DAY. DEEP ATLANTIC  MOISTURE
WILL ARRIVE THIS WEEKEND PROMOTING MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS AND MORE RESTRICTIONS.

CONFIDENCE TABLE...

            19-01Z        01-07Z        07-13Z        13-19Z
KCLT       HIGH 100%     HIGH 100%     HIGH  86%     HIGH  91%
KGSP       HIGH  92%     HIGH 100%     HIGH  86%     HIGH  91%
KAVL       HIGH 100%     HIGH  95%     HIGH  84%     HIGH  90%
KHKY       HIGH 100%     HIGH 100%     MED   70%     HIGH  96%
KGMU       HIGH  92%     HIGH 100%     HIGH  86%     HIGH  96%
KAND       HIGH 100%     HIGH  95%     HIGH  85%     HIGH  98%

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...DEO
NEAR TERM...JAT/LG
SHORT TERM...NED
LONG TERM...DEO
AVIATION...LG