822  
FXUS62 KGSP 021459  
AFDGSP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC  
1059 AM EDT SUN AUG 2 2015  
   
SYNOPSIS
 
 
DRY HIGH PRESSURE WILL REMAIN IN PLACE ACROSS THE AREA THROUGH  
MONDAY. LOW LEVEL MOISTURE WILL GRADUALLY RETURN THROUGH THE WEEK AS  
ANOTHER COLD FRONT APPROACHES FROM THE NORTH THEN MOVES INTO THE  
AREA AND STALLS.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
AS OF 1045 AM EDT SUNDAY...DEWPOINTS ARE RUNNING A BIT LOWER THAN  
FORECAST SO HAVE MADE SOME ADJUSTMENTS ACCORDINGLY. OTHER GRIDS IN  
GOOD SHAPE FOR THE MOST PART. HRRR AND OTHER HIRES GUIDANCE DO STILL  
WANT TO DEVELOP SOME CONVECTION OVER THE MOUNTAINS THIS AFTERNOON  
DESPITE THE DRY DEWPOINTS...BUT ENOUGH LAPSE RATE ALOFT FOR SOME  
MINIMAL CAPE VALUES...SO HAVE KEPT THE SLIGHT CHANCE POPS FOR THIS  
AFTERNOON.  
 
1045 UTC UPDATED...SKY COVER HAS BEEN UPDATED TO ACCOUNT FOR CIRRUS  
CROSSING THE INTERSTATE 77 CORRIDOR AND MOVING INTO SW SN AND NE GA.  
WINDS WERE UPDATED FROM THE LATEST NAM GUIDANCE.  
 
AT 230 AM EDT SUNDAY...AN UPPER RIDGE WILL REMAIN OVER THE WESTERN  
USA TODAY AND TONIGHT...WHILE A TROUGH PERSISTS OVER THE EAST.  
WEAK...CHANNELED SHORTWAVE ENERGY WILL MOVE THROUGH BASE OF THE  
TROUGH OVER VA TODAY. AT THE SURFACE...A STATIONARY FRONT WILL  
REMAIN NEAR THE COASTS OF NC...SC AND GA. THE BULK OF MOISTURE  
ASSOCIATED WITH THIS FEATURE WILL REMAIN SOUTHEAST OF OUR AREA...AS  
WILL ASSOCIATED PRECIPITATION. MOISTURE IS EXPECTED TO INCREASE OVER  
OUR AREA HOWEVER...AND FORECAST MODEL SOUNDINGS WILL BE SUPPORTIVE  
OF CONVECTION THIS AFTERNOON AND EVENING IN THE MOUNTAINS.  
TEMPERATURES WILL SLIGHTLY ABOVE NORMAL.  
 

 
   
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
 
 
AS OF 205 AM SUNDAY...EXPECT ANOTHER QUITE DAY MONDAY BEFORE A  
PATTERN CHANGE AND A RETURN THE MORE TYPICAL DIURNAL THUNDERSTORM  
REGIME. AN UPPER TROF WILL BE OVER THE ERN US WITH DRY HIGH  
PRESSURE IN PLACE AT THE SFC. EXPECT THE DEWPOINTS TO MIX OUT ONCE  
AGAIN INTO THE 50S MOST PLACES...KEEPING INSTABILITY AT A MINIMUM.  
THE GUIDANCE SHOWS A LOW PRESSURE SYSTEM FORMING OVER THE GULF AND  
MOVING NE NEAR THE ATLANTIC COAST ALONG AN OLD FRONTAL BOUNDARY.  
HOWEVER...MOST MDLS KEEP THE LOW SOUTH AND EAST OF THE AREA WITH  
MINIMAL EFFECT OVER THE CWFA. THEREFORE...NO SIGNIFICANT CONVECTION  
IS EXPECTED. TEMPERATURES WILL BE WELL ABOVE NORMAL.  
 
THE UPPER TROF BEGINS TO LIFT TUE WITH A WLY FLOW DEVELOPING. AT THE  
SFC...A WEAK FRONTAL SYSTEM SAGS INTO THE AREA FROM THE NORTH. A  
MOIST LOW LEVEL FLOW RETURNS BRINGING INCREASE LOW LEVEL MOISTURE.  
DEWPOINTS WILL MIX OUT...BUT ONLY TO AROUND 60. THIS WILL BRING AN  
INCREASE IN INSTABILITY AND POTENTIAL FOR AFTERNOON CONVECTION.  
STILL...COVERAGE APPEARS TO BE LIMITED TO ISOLATED...AND MAINLY OVER  
NC. TEMPS WILL RISE A COUPLE OF DEGREES FROM MON.  
 

 
   
LONG TERM /WEDNESDAY THROUGH SATURDAY/
 
 
AS OF 320 AM SUNDAY...THE PATTERN CHANGE IS FULLY UNDERWAY AT THE  
BEGINNING OF THE MEDIUM RANGE. ZONAL FLOW ALOFT BRINGS A SERIES OF  
SHORTWAVES ACROSS THE AREA THRU THU. STRONGER SHORT WAVES MOVE IN  
BEGINNING FRI BRINGING A RETURN TO THE UPPER TROF TO THE EASTERN  
CONUS. ANOTHER SHORTWAVE MOVES THRU ON SAT REINFORCING THE TROF. AT  
THE SFC...A WEAK COLD FRONT SAGS SOUTH AND STALLS ACROSS THE AREA.  
THE SHORTWAVES HELP DEVELOP A SERIES OF LOW PRESSURE CENTERS WHICH  
THEN MOVE ALONG THE FRONT AND ACROSS THE AREA THRU FRI. THIS WILL  
BRING INCREASING CHANCES OF MAINLY DIURNAL CONVECTION. THAT SAID...  
CONVECTION COULD LINGER THRU THE NITE AS THE CWFA WILL BE IN THE  
PATH OF ANY POTENTIAL MCS ACTIVITY. A STRONGER LOW PRESSURE CENTER  
DEVELOPS ON SAT AND MOVES EAST OF THE AREA POSSIBLY DRAGGING THE  
FRONT SOUTH OF THE AREA. HOWEVER...THE MOIST UNSTABLE AIR MASS WILL  
LINGER...KEEPING THE CHC OF CONVECTION IN PLACE...ALTHOUGH WITH A  
LOWER RESULTING POP. TEMPS SHOW A SLOW BUT STEADY COOLING TREND THRU  
THE PERIOD...ENDING UP NEAR NORMAL BY SAT.  
 

 
   
AVIATION /15Z SUNDAY THROUGH THURSDAY/
 
 
AT KCLT...VFR. FEW TO OCCASIONALLY SCT CU GENERALLY 8-9KFT LATE THIS  
MORNING AND WILL LIKELY LOWER SOME AS MIXING INCREASES...BUT  
COVERAGE IS GENERALLY NOT EXPECTED TO BE SUFFICIENT FOR A CIG.  
INSTABILITY WILL BE TOO LIMITED FOR CONVECTION. LIGHT WINDS WILL BE  
FROM THE NE TODAY....VEERING SE TONIGHT. SOME GUIDANCE IS LEANING  
TOWARD DAYBREAK FOG MONDAY MORNING AT SURROUNDING SITES...BUT OTHER  
GUIDANCE IS LESS PESSIMISTIC.  
 
ELSEWHERE...VFR. SO FAR MOUNTAIN FOG HAS BEEN LIMITED TO VALLEYS  
WELL SW OF KAVL. HIGH VFR CIGS ARE POSSIBLE EARLY TODAY AS CIRRUS  
MOVES OVERHEAD. LOW VFR CIGS LATER TODAY WILL BE POSSIBLE IN THE NC  
MOUNTAINS WHERE CONVECTION WILL COULD OCCUR IN BETTER INSTABILITY.  
LIGHT WINDS WILL BE FROM THE NE MORNING...EXCEPT AT KAVL WHERE THEY  
WILL VEER FROM NW TO SE TODAY AND RETURN TO NW TONIGHT...AND KHKY  
WHERE THEY BACK FROM NE TO N TONIGHT. GUIDANCE IS BECOMING MORE  
SUPPORTIVE OF DAYBREAK FOG ON MONDAY...BUT THE BEST BET IS INITIALLY  
IN MOUNTAIN VALLEYS WHERE COOL AIR WILL POOL.  
 
OUTLOOK...GRADUALLY INCREASING PRECIPITATION/RESTRICTION CHANCES  
THROUGH MID WEEK AS MOIST SOUTHERLY FLOW RETURNS.  
 
CONFIDENCE TABLE...  
 
15-21Z 21-03Z 03-09Z 09-12Z  
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%  
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%  
KAVL HIGH 100% HIGH 100% HIGH 100% MED 66%  
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 94%  
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%  
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 94%  
 
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...RWH  
NEAR TERM...TDP  
SHORT TERM...RWH  
LONG TERM...RWH  
AVIATION...JAT/TDP  
 
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