000
FXUS62 KGSP 160834
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
434 AM EDT SUN JUN 16 2013

.SYNOPSIS...
DRY HIGH PRESSURE OVER THE CAROLINAS WILL DRIFT OFF THE CAROLINA
COAST THROUGH SUNDAY AS THE NEXT COLD FRONT CROSSES THE UPPER
MISSISSIPPI AND OHIO VALLEYS. EXPECT THIS FRONT TO BRING GOOD
COVERAGE OF RAINFALL IN THE EARLY HALF OF THE WEEK. THE FRONT WILL
THEN STALL FROM WEST TO EAST JUST SOUTH OF OUR REGION AND SLOWLY
DISSIPATE LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 430 AM EDT...THE FORECAST REMAINS ON TRACK WITH MODEL PROFILES
CONTINUING TO SHOW SHALLOW MOISTURE TRAPPED BELOW AN 800 TO 700 MB
INVERSION LAYER ACROSS THE AREA. IR SATELLITE IMAGERY IS SHOWING THE
RESULTANT SCATTERED STRATOCUMULUS DEVELOPING IN THIS LAYER...AND
THESE SCATTERED CLOUDS MAY LINGER THROUGH THE MUCH OF THE DAY
DESPITE HEATING...WITH HIGHER CLOUDS THICKENING ALOFT FROM THE W.
DEEPER MOISTURE WILL SLOWLY RETURN TO PROFILES FROM THE SW
TODAY...WITH A SERIES OF SHORTWAVES MOVING FROM THE MID MS RIVER
VALLEY TO THE BASE OF THE SRN APPALACHIANS THIS EVENING THROUGH
TONIGHT. EXPECT SCATTERED CONVECTION TO BEGIN ACROSS THE NC MTNS
THIS AFTN AS LAPSE RATES STEEPEN ALOFT...WITH ISOLD TO SCT COVERAGE
SPREADING EAST INTO THE FOOTHILLS AND PIEDMONT DURING THE EVENING
HOURS. THE FOCUS FOR CONTINUED OVERNIGHT CONVECTION WILL THEN RETURN
TO THE MTNS...ESPECIALLY SRN SECTIONS...WITH IMPROVED FORCING FROM
WEAK UPPER WAVES AND LOW LEVEL SW UPSLOPE FLOW. EXPECT NEAR NORMAL
MAX TEMPS THIS AFTN...WITH MINS 1 TO 2 CATEGORIES ABOVE NORMAL
TONIGHT IN INCREASING CLOUDS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM EDT SUNDAY...NOT MUCH HAS CHANGED IN THE LAST 24 HOURS
WITH REGARDS TO WEATHER IN THE SHORT TERM.  BY MONDAY...UPPER LEVEL
RIDGE THAT IS CURRENTLY IN PLACE ACROSS THE SOUTHEAST WILL FLATTEN
OUT AND SURFACE HIGH PRESSURE WILL SHIFT EASTWARD OVER THE
ATLANTIC.  IN RESPONSE...SOUTHERLY FLOW WILL ADVECT IN A MARITIME
AIRMASS LEADING TO DEWPOINTS CLIMBING INTO THE THE UPPER 60S ACROSS
THE PIEDMONT AND MID 60S IN THE HIGHER TERRAIN.  THIS INCREASED
MOISTURE WILL LEAD TO INCREASING INSTABILITY AS EVIDENT IN FORECAST
SOUNDINGS.  BOTH NAM AND GFS SOUNDINGS ARE FAIRLY UNSTABLE WITH
SBCAPE VALUES NEAR 1000J/KG BY LATE MORNING MONDAY.  HOWEVER...BOTH
MODELS PLACE A SUBSTANTIAL CAPPING INVERSION IN THE LOW LEVELS
DURING THE MORNING HOURS.  THE CAP IS EXPECTED TO HOLD INTO THE
AFTERNOON HOURS WHERE BY THEN INCREASING SKY COVER SHOULD DAMPEN
OVERALL INSTABILITY ACROSS THE REGION.  WITH THAT SAID...THE AREA OF
GREATEST INSTABILITY ON MONDAY WILL LIE ACROSS NORTHEAST GEORGIA AND
THE CAROLINA PIEDMONTS.  IT WILL BE IN THIS REGION WHERE THE MORE
INTENSE UPDRAFTS WILL BE POSSIBLE...ALTHOUGH NOT EXPECTED TO REACH
SEVERE LIMITS.  ASIDE FROM THUNDERSTORM ACTIVITY...SHOWERS WILL
SPREAD ACROSS THE REGION ON MONDAY AFTERNOON LEADING LIKELY POPS
ACROSS MOST OF THE AREA.  TEMPERATURES ON MONDAY WILL BE NEAR NORMAL
FOR HIGHS AND SLIGHTLY ABOVE NORMAL FOR LOWS AS SKY COVER WILL BE
DENSE THROUGH MONDAY AND INTO TUESDAY.

MEANWHILE...SURFACE LOW LOCATED OVER SOUTHERN ONTARIO AND THE
NORTHEAST UNITED STATES WILL SPREAD A COLD FRONT ACROSS THE OHIO AND
TENNESSEE VALLEYS.  THIS FRONT WILL BEGIN TO PUSH INTO WESTERN NORTH
CAROLINA ON TUESDAY AFTERNOON CAUSING AN INCREASE IN SHOWER
ACTIVITY.  SOLID LIKELY POPS OVERSPREAD THE ENTIRE CWA ON TUESDAY
AFTERNOON DUE TO CONVERGENCE ALONG THE BOUNDARY AS IT MOVES
THROUGH.  INSTABILITY SHOULD BE FAIRLY LIMITED ON TUESDAY AS
CONTINUED SKY COVER LEADS TO MINIMAL HEATING AND DAYTIME HIGH
TEMPERATURES STRUGGLING TO TOP 80 IN MOST AREAS.  THEREFORE...
CONSIDERING LOW INSTABILITY COMBINED WITH MINIMAL BULK SHEAR...THE
SEVERE WEATHER THREAT LOOKS TO BE RATHER LOW AT THIS TIME THUS
LEADING TO MORE OF A GENERAL THUNDERSTORM OUTLOOK.  LATEST MODEL
GUIDANCE CONTINUES TO THE SLOW PROGRESSION OF THE FRONT INTO THE
MIDLANDS/LOW COUNTRY BY WEDNESDAY MORNING...WHICH IS A CHANGE FROM
PREVIOUS MODEL RUNS WHICH WANTED TO STALL THE FRONT ACROSS THE
UPSTATE INTO WEDNESDAY.  LOWERED POPS TO CHANCE LEVELS ACROSS THE
ENTIRE AREA AS SOME POST FRONTAL STRATIFORM PRECIPITATION COULD
LINGER ON WEDNESDAY.  ALTHOUGH THE FRONT SHOULD BE LOCATED TO THE
SOUTH...TEMPERATURES AND DEWPOINTS WONT SUFFER MUCH AS HIGHS ON
WEDNESDAY WILL BE AROUND 80 AND DEWPOINTS REMAIN IN THE MID TO UPPER
60S.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 245 AM EDT SUNDAY...ASIDE FROM HIGH TEMPERATURES...THE
EXTENDED PERIOD LOOKS RATHER NORMAL FOR THIS TIME OF YEAR.  HIGH
PRESSURE WILL BUILD IN ACROSS THE APPALACHIANS ON THURSDAY MORNING
AND IMMEDIATELY BEING PUSHING EASTWARD...EVENTUALLY SETTING UP
OFFSHORE BY THURSDAY EVENING.  IN RESPONSE...RETURNING SOUTHERLY
FLOW WILL USHER IN A GRADUAL WARMING TREND.  KEPT LOW END CHANCE
POPS IN THE FORECAST FOR THURSDAY THROUGH SATURDAY EVENING...MAINLY
DUE TO DAYTIME HEATING INDUCED CONVECTION.  HIGH TEMPERATURES
THROUGH THE PERIOD WILL START OFF BELOW NORMAL AND INCREASE TO NEAR
NORMAL LEVELS...LOWS SHOULD BE AT OR ABOVE NORMAL.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
AT KCLT...SCT STRATOCUMULUS WILL PERSIST ACROSS THE AREA TODAY WITH
MOISTURE TRAPPED JUST BELOW AN 800 TO 700 MB INVERSION.
MEANWHILE...HIGHER LEVEL CLOUDS WILL INCREASE AND THICKEN AHEAD OF
WEAK SHORTWAVES MOVING EAST FROM THE MS RIVER VALLEY. WILL KEEP THE
KCLT FORECAST DRY...BUT ISOLD TSTMS COULD MOVE EAST OFF THE MTNS
LATE IN THE DAY AND POSSIBLY APPROACH THE PIEDMONT. WINDS WILL
REMAIN SOLIDLY S TO SW AT 10 KT OR LESS THROUGH THE PERIOD.

ELSEWHERE...EXPECT THICKENING CIRRUS ABOVE SCT TO BKN STRATOCUMULUS
TRAPPED BENEATH THE 800 TO 700 MB INVERSION LAYER ACROSS THE REGION.
SCT CONVECTION WILL START ACROSS THE NC MTNS THIS AFTERNOON AS
MOISTURE INCREASES AND WEAK UPPER TRIGGERING ARRIVES FROM THE WEST.
THE CONVECTION MAY MOVE OFF THE MTNS THROUGH THE EVENING HOURS TO
APPROACH THE FOOTHILL TAF SITES...BUT CONFIDENCE IS ONLY HIGH ENOUGH
FOR A PROB30 FOR TSRA AT KAVL AT PRESENT. EXPECT S TO SW SFC WINDS
LESS THAN 10 KT.

OUTLOOK...THE CHANCES FOR SHRA/TSTMS AND ASSOCIATED FLIGHT
RESTRICTIONS WILL INCREASE MON THROUGH TUE WITH THE ARRIVAL OF A
FRONT. CONDITIONS WILL REMAIN UNSETTLED THROUGH MUCH OF THE WEEK.

CONFIDENCE TABLE...

            08-14Z        14-20Z        20-02Z        02-08Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH  94%     HIGH 100%     HIGH 100%     HIGH  94%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

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...HG
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...HG