750  
FXUS62 KGSP 161458  
AFDGSP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC  
1058 AM EDT TUE JUL 16 2019  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER ACROSS THE AREA FOR  
MUCH OF THE WEEK, WHILE THE REMNANTS OF BARRY REMAIN TO THE WEST OF  
THE REGION. HOT AND HUMID CONDITIONS, WITH SCATTERED AFTERNOON AND  
EVENING SHOWERS AND THUNDERSTORMS CAN BE EXPECTED EACH DAY.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
AS OF 10:45AM EDT TUESDAY: FORECAST ON TRACK WITH A FEW  
THUNDERSTORMS POSSIBLE THIS AFTERNOON, PRIMARILY OVER THE  
MOUNTAINS OF WESTERN NORTH CAROLINA. CURRENT RADAR IS CLEAR, AND  
UPDATED POP TREND TO INCORPORATE LATEST HIGH-RES MODEL GUIDANCE  
WHICH HAS SHOWERS INCREASING THIS AFTERNOON.  
 
SHORT WAVE RIDGING WILL REMAIN OVER THE CAROLINAS TODAY, DOWNSTREAM  
OF THE WEAKENING CIRCULATION OF TC BARRY REMNANTS. THIS FEATURE WILL  
CONTINUE TO CREATE AN ENVIRONMENT THAT IS NOT IDEAL FOR CONVECTIVE  
INITIATION, BUT AS WAS THE CASE YESTERDAY, SUFFICIENT INSTABILITY  
AND LOW LEVEL MOISTURE WILL EXIST TO ALLOW ISOLATED TO WIDELY  
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON. THE  
HRRR WAS THE ONLY GUIDANCE SOURCE THAT ACCURATELY INITIATED  
CONVECTION ACROSS UPSTATE SC YESTERDAY AFTERNOON (AND EVEN IT DID  
NOT DEVELOP CONVECTION FAR ENOUGH TO THE NORTH), AND IT IS DOING  
SOMETHING SIMILAR AGAIN THIS AFTERNOON, IN THE VICINITY OF LINGERING  
WEAK TROUGH AXIS/SUBTLE BOUNDARY.  
 
MEANWHILE, TERRAIN DIFFERENTIAL HEATING SHOULD AGAIN WORK ITS MAGIC  
IN ALLOWING ISOLATED TO WIDELY SCATTERED CELLS TO DEVELOP NEAR THE  
PEAKS AND RIDGE TOPS DURING EARLY/MID AFTERNOON. ONE KEY INGREDIENT  
THAT IS MISSING FROM YESTERDAY IS THAT WITH THE APPROACH OF THE  
TROUGH ASSOCIATED WITH BARRY'S REMNANTS, MID-LEVEL FLOW SHOULD  
INCREASE ENOUGH TO RESULT IN MEAN CLOUD-BEARING WINDS OF 10-15 KTS.  
THEREFORE, WHILE MODEST LEVELS OF DCAPE WILL PROBABLY RESULT IN  
DEVELOPMENT OF NOT-ESPECIALLY-ACTIVE OUTFLOW BOUNDARIES, FASTER CELL  
MOTION SUGGESTS CONVECTION SHOULD HAVE BETTER SUCCESS IN MAKING IT  
OFF THE HIGH TERRAIN INTO THE NC FOOTHILLS AND PIEDMONT THIS  
AFTERNOON. ALL THAT'S TO SAY THAT WE CAN'T SEE ANY REASON WHY  
ISOLATED CONVECTION WON'T BE POSSIBLE AT ANY LOCATION ACROSS THE CWA  
LATER TODAY, AND SLIGHT CHANCE POPS ARE ADVERTISED EVERYWHERE EAST  
OF THE MTNS. CONVECTION SHOULD AGAIN DIMINISH QUICKLY THIS  
EVENING.  
 
WITH LINGERING OUTFLOW CIRRUS BECOMING INCREASINGLY THIN ACROSS THE  
AREA TODAY, AND HEIGHTS CONTINUING TO SLOWLY RISE, THE WARMING TREND  
IS EXPECTED TO CONTINUE, AND MAXES ARE EXPECTED TO TOP OUT ABOUT A  
CATEGORY ABOVE CLIMO. THIS MEANS MUCH OF THE PIEDMONT IS LIKELY TO  
SEE THE MID-90S. HOWEVER, DEWPOINTS ARE FORECAST TO MIX OUT JUST  
ENOUGH TO SEE MAXIMUM HEAT INDEX VALUES CONFINED TO THE 95-100  
RANGE, WELL BELOW ADVISORY CRITERIA OF 105.  
 

 
   
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
 
 
AS OF 230 AM TUESDAY: THE REMNANT MID-LVL TROUGH FROM BARRY WILL  
CROSS THE OHIO VALLEY ON WEDNESDAY AND INTO THE SOUTHERN  
APPALACHIANS WEDNESDAY NIGHT. THIS WILL LIKELY ENHANCE CONVECTIVE  
COVERAGE OVER THE MOUNTAINS LATE WEDNESDAY THRU THURSDAY. CONFIDENCE  
ON HOW MUCH CONVECTION EAST OF THE MOUNTAINS IS STILL LOW, AS  
GUIDANCE HAS TRENDED LESS EXCITED THAN PREVIOUS RUNS. STILL, WILL GO  
WITH CHC POPS WEDNESDAY NIGHT EVERYWHERE, WITH SOME LIKELIES NEAR  
THE TN BORDER. CONVECTIVE COVERAGE SHOULD REMAIN A LITTLE ELEVATED  
ON THURSDAY, AS PWATS NEAR 2.0" FROM BARRY WILL STILL BE OVER THE  
AREA. IT WILL BE HOT AND HUMID BOTH DAYS, WITH HIGHS MAINLY IN THE  
LOWER TO MID 90S IN THE PIEDMONT AND MIDDLE TO UPPER 80S IN THE  
MOUNTAIN VALLEYS. AS USUAL WITH SUMMERTIME CONVECTION, THERE WILL BE  
A SMALL PULSE SEVERE AND LOCALIZED FLOODING THREAT.  
 

 
   
LONG TERM /FRIDAY THROUGH MONDAY/
 
 
AS OF 300 AM TUESDAY: A MID-LEVEL RIDGE WILL BUILD AND PERSIST  
ACROSS THE EASTERN CONUS FRIDAY THRU THE WEEKEND, THEN A LONGWAVE  
TROUGH WILL BEGIN TO DIG ACROSS THE EASTERN CONUS EARLY NEXT WEEK.  
THIS WILL RESULT IN MAX TEMPS BACK TO THE MID TO POSSIBLY SOME UPPER  
90S, WITH DEWPTS IN THE 70S. THIS WILL COMBINE TO PRODUCE HEAT INDEX  
VALUES IN THE 100-105 RANGE ACROSS THE PIEDMONT EACH AFTERNOON. SOME  
LOCATIONS IN THE UPPER SAVANNAH VALLEY AND EASTERN UPSTATE MAY HAVE  
HEAT INDEX VALUES ABOVE 105 FRIDAY THRU SUNDAY. DESPITE THE UPPER  
RIDGE CENTERED NEARLY DIRECTLY OVER THE FORECAST AREA, DAILY DIURNAL  
CONVECTION IS FORECAST TO TRIGGER ACROSS THE MOUNTAINS AND ALONG A  
PERSISTENT "HEAT" PIEDMONT SFC TROUGH. GUIDANCE HAS SLIGHTLY ABOVE  
CLIMO POPS, MAINLY IN THE CHC TO LOW LIKELY RANGE EACH DAY.  
 

 
   
AVIATION /15Z TUESDAY THROUGH SATURDAY/
 
 
AT KCLT AND ELSEWHERE: LIFR CONDITIONS ARE FORECAST TO PERSIST AT  
KAVL THROUGH 13Z, AND POSSIBLY AS LATE AS 14Z. THERE HAVE BEEN BRIEF  
PERIODS OF VLIFR THROUGHOUT THE MORNING HOURS, AND WOULDN'T RULE OUT  
ADDITIONAL PERIODS OF SUCH, BUT IT'S NOT LIKELY. OTHERWISE, VFR  
CONDITIONS ARE FORECAST AT THE TERMINALS THROUGH AT LEAST THIS  
EVENING. ISOLATED TO WIDELY SCATTERED CONVECTION WILL DEVELOP OVER  
THE AREA THIS AFTERNOON, WITH THE BEST CHANCES AGAIN EXPECTED NEAR  
KAVL, WHERE VCTS/PROB30 FOR TSRA ARE CARRIED FROM MID-AFTERNOON INTO  
THE EARLY EVENING. CONVECTION IS CERTAINLY POSSIBLE AT THE OTHER  
SITES, BUT COVERAGE IS EXPECTED TO BE LIMITED ENOUGH TO PRECLUDE A  
MENTION ATTM. ANY CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING.  
FOG/LOW STRATUS WILL BE PRIMARILY A CONCERN IN THE MTN VALLEYS WEST  
OF KAVL EARLY WED MORNING, BUT IS NOT AT ALL OUT OF THE QUESTION AT  
KAVL, ESPECIALLY IF THE SITE RECEIVES ANOTHER ROUND OF RAIN THIS  
AFTERNOON (MVFR VISBY IS CARRIED THERE FOR THE TIME BEING). WINDS  
WILL INCREASE OUT OF THE SW AT 5-10 KTS BY EARLY AFTERNOON BEFORE  
BECMG LIGHT/VARIABLE AGAIN TUE EVENING.  
 
OUTLOOK: TYPICAL SCATTERED DIURNAL CONVECTION IS EXPECTED THROUGH  
THE WEEK, ESPECIALLY OVER THE MOUNTAINS. PATCHY MOUNTAIN VALLEY  
FOG AND LOW CIGS REMAIN POSSIBLE DURING THE OVERNIGHT AND EARLY  
MORNING HOURS.  
 
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% HIGH 83%  
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:  
 
WWW.WEATHER.GOV/GSP/AVIATION  
 

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

 
 

 
SYNOPSIS...ARK  
NEAR TERM...JDL/WJM  
SHORT TERM...ARK  
LONG TERM...ARK  
AVIATION...JDL  
 
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