548  
FXUS62 KGSP 280442  
AFDGSP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC  
1242 AM EDT SAT JUN 28 2025  
   
SYNOPSIS
 
 
TEMPERATURES ARE FORECAST TO BE NEAR OR SLIGHTLY ABOVE NORMAL  
THROUGH THE THE FIRST HALF OF NEXT WEEK. EXPECT AFTERNOON AND  
EVENING SHOWERS AND THUNDERSTORMS EACH DAY. A WEAK COLD FRONT MAY  
REACH OUR REGION BY TUESDAY THEN DRIFT SOUTH OF OUR AREA THROUGH MID  
WEEK.  
 

 
   
NEAR TERM /THROUGH TODAY/
 
 
AS OF 1235 AM EDT SATURDAY: A FEW STUBBORN SHOWERS AND THUNDERSTORMS  
ARE CONTINUING TO POP-UP IN THE NC PIEDMONT. NOTHING SEVERE BUT  
ENOUGH TO WATCH UNTIL THEY DECAY, HOPEFULLY SOON. OTHER THAN THAT,  
NO REAL CHANGES TO THE FORECAST AT THIS TIME.  
 
EXPECT ANOTHER ROUND OF MOUNTAIN VALLEY FOG OVERNIGHT WITH SOME FOG  
POSSIBLE NEAR LAKES AND RIVERS, OR LOCATIONS WITH HEAVY RAINFALL.  
LOWS WILL BE NEAR NORMAL FOR THE MOUNTAINS AND A FEW DEGREES ABOVE  
NORMAL ELSEWHERE.  
 
HEIGHTS ARE SLIGHTLY LOWER SATURDAY AS A WEAK UPPER LOW MOVES NORTH  
INTO THE WESTERN CAROLINAS. THE ATMOS BECOMES VERY UNSTABLE AGAIN  
WITH SLIGHTLY BETTER SHEAR. DCAPE AND SFC DELTA THETA-E ARE NOT AS  
HIGH AS PREVIOUS DAYS, BUT NOT ZERO. THEREFORE, THE OVERALL THREAT  
OF SEVERE STORMS IS LOWER, BUT AN ISOLATED DAMAGING DOWNBURST IS  
POSSIBLE. PW VALUES REMAIN HIGH WITH SE STEERING FLOW AGAIN WHICH  
KEEPS A LOW END THREAT OF TRAINING OF CELLS OR ANCHORING ALONG SE  
FACING RIDGES. ISOLATED FLOODING CAN'T BE RULE OUT. HIGHS WILL BE  
NEAR NORMAL FOR THE MOUNTAINS AND A FEW DEGREES ABOVE NORMAL  
ELSEWHERE.  
 

 
   
SHORT TERM /TONIGHT THROUGH MONDAY/
 
 
AS OF 1215 PM FRIDAY: THE FORECAST CONTINUES TOMORROW NIGHT INTO  
SUNDAY WITH A BROAD BERMUDA HIGH JUST OFF THE EAST COAST AND  
BROAD/FLAT UPPER RIDGING EXTENDING ACROSS THE SOUTHERN CONUS. MORE  
ACTIVE NORTHERN STREAM FLOW WILL BE DISPLACED NORTH ALONG THE  
CANADIAN BORDER WHERE A TROUGH WILL BE SLIDING ACROSS THE NORTHERN  
PLAINS AND INTO THE GREAT LAKES REGION. A WARM AND HUMID AIRMASS  
WILL REMAIN ENTRENCHED ACROSS THE SOUTHERN APPALACHIANS WITH  
FAVORABLE CONDITIONS FOR ABOVE AVERAGE COVERAGE OF DIURNAL  
THUNDERSTORMS BOTH SUNDAY AND MONDAY. COVERAGE MAY TICK HIGHER ON  
MONDAY AS THE TROUGH DROPS TOWARDS THE OHIO VALLEY AND HEIGHTS  
GRADUALLY LOWER. AS WITH ANY SUMMERTIME CONVECTION, LOCALLY HEAVY  
RAINFALL AND A FEW WET MICROBURSTS WILL BE POSSIBLE WITH ANY STRONG  
STORMS. STEERING FLOW WILL BE WEAK AS WELL WITH VERY SLOW MOVING  
STORMS THAT COULD POSE A THREAT FOR ISOLATED FLASH FLOODING SHOULD  
SEVERAL INCHES OF RAIN QUICKLY ACCUMULATE. TEMPERATURES WILL REMAIN  
SEASONABLE.  
 

 
   
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
 
 
AS OF 1231 PM FRIDAY: PREVIOUSLY MENTIONED TROUGH WILL SWING ACROSS  
THE OHIO VALLEY AND INTO NEW ENGLAND ON TUESDAY WITH THE TROUGH AXIS  
ALSO PASSING THROUGH THE APPALACHIANS. AN ATTENDANT SURFACE COLD  
FRONT WILL ALSO DROP TOWARDS THE AREA WHICH WILL HELP SUPPORT THE  
GREATEST RAIN CHANCES OF THE PERIOD. NUMEROUS TO WIDESPREAD  
THUNDERSTORMS ARE EXPECTED AS THE FRONT MOVES INTO THE AREA DURING  
PEAK HEATING ON TUESDAY. FLOW REMAINS WEAK, HOWEVER, BUT AT LEAST  
LOOSELY ORGANIZED CONVECTIVE CLUSTERS/LINEAR SEGMENTS SHOULD BE ABLE  
TO ORGANIZE ALONG COMPOSITE COLD POOLS. THEREAFTER, FORECAST  
CONFIDENCE BEGINS TO LOWER BY MID TO LATE NEXT WEEK AS GUIDANCE  
DIVERGES WITH REGARDS TO HOW FAR SOUTH THE FRONTAL BOUNDARY MAKES  
IT. DRIER AIR BEHIND THE BOUNDARY WOULD RESULT IN A NOTABLE  
DOWNTREND IN DIURNAL CONVECTION WITH JUST ISOLATED POTENTIAL. SHOULD  
THE FRONT STALL ACROSS OR NEAR THE AREA, HOWEVER, ABOVE AVERAGE RAIN  
CHANCES COULD CONTINUE. WILL KEEP AT LEAST A SLIGHT CHANCE FOR  
CONVECTION IN THE FORECAST UNTIL GUIDANCE COMES INTO BETTER  
AGREEMENT.  
 

 
   
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
 
 
AT KCLT AND ELSEWHERE: VFR CONDITIONS EXPECTED FOR MOST TERMINALS  
THROUGH MUCH OF THE FORECAST PERIOD. A FEW ISOLATED SHOWERS AND  
STORMS ARE STILL IN THE AREA, BUT NO THREAT TO THE TERMINALS AT THIS  
TIME. OTHERWISE, EXPECT LINGERING CONVECTIVE DEBRIS ACROSS THE AREA  
THROUGH TONIGHT, WHILE REMAINING VFR. PUT 1SM AND OVC002 TAF LINE AT  
KAVL STARTING AT 09Z SATURDAY FOR MOUNTAIN VALLEY FOG/LOW STRATUS AS  
THERE IS ANOTHER GOOD CHANCE FOR THIS TO HAPPEN ONCE AGAIN JUST  
BEFORE DAYBREAK, SIMILAR TO EARLY THIS MORNING AS LONG AS CONVECTIVE  
DEBRIS SCATTERS OUT TO ALLOW FOR RADIATIONAL ENHANCEMENT.  
SOUTHWESTERLY WINDS WILL GRADUALLY SUBSIDE LATER THIS EVENING AND  
PICK BACK UP BY MID-MORNING SATURDAY AND LAST THROUGH THE REST OF  
THE PERIOD OUTSIDE OF A WIND SHIFT FROM AN OUTFLOW BOUNDARY AS  
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE DURING PEAK HEATING ON  
SATURDAY ONCE AGAIN. PLACED A PROB30 AT ALL TAF SITES FOR ANOTHER  
ROUND OF SUMMERTIME POP UP SHOWERS AND THUNDERSTORMS WITH ASSOCIATED  
RESTRICTIONS.  
 
OUTLOOK: DAILY CHANCES FOR AFTERNOON AND EVENING SHOWERS AND  
THUNDERSTORMS INTO NEXT WEEK. FOG AND/OR LOW STRATUS POSSIBLE  
EACH MORNING IN THE USUAL MOUNTAIN VALLEYS AS WELL AS NEAR LAKES  
AND RIVERS.  
 

 
   
GSP WATCHES/WARNINGS/ADVISORIES
 
 
GA...NONE.  
NC...NONE.  
SC...NONE.  
 

 
 

 
 
SYNOPSIS...DEO  
NEAR TERM...CAC/CP/RWH  
SHORT TERM...TW  
LONG TERM...TW  
AVIATION...CAC  
 
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