777  
FXUS62 KCHS 181956  
AFDCHS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON SC  
356 PM EDT THU JUL 18 2019  
   
SYNOPSIS
 
 
INTO EARLY NEXT WEEK, THE AREA WILL REMAIN HOT AND HUMID  
BETWEEN AN INLAND TROUGH OF LOW PRESSURE AND ATLANTIC HIGH  
PRESSURE. A COLD FRONT IS EXPECTED TO STALL OVER OR CLOSE TO  
THE REGION BY THE MIDDLE OF NEXT WEEK, BRINGING HIGHER RAIN  
CHANCES AND SOMEWHAT COOLER TEMPERATURES.  
 

 
   
NEAR TERM /UNTIL 6 AM FRIDAY MORNING/
 
 
UNTIL SUNSET: RADAR SHOWS THUNDERSTORMS FAR INLAND AND ALONG  
PORTIONS OF THE SEA BREEZE. SPC MESOSCALE ANALYSIS CONTINUES TO  
SHOW MLCAPES GETTING UP TO 2,500-3,000 J/KG AND DCAPES  
APPROACHING 1,200 J/KG. THIS COULD LEAD TO SOME MARGINALLY  
SEVERE PULSE STORMS WITH DAMAGING WINDS. STEERING WINDS ALOFT  
ARE FAIRLY LIGHT, WHICH IS CAUSING SLOW STORM MOVEMENTS. WITH  
DEEP MOISTURE IN PLACE (PWATS AROUND 2"), VERY HEAVY RAINFALL IS  
A CONCERN WITH LOCAL FLOODING POSSIBLE IN LOW-LYING AND POORLY  
DRAINED AREAS. CAMS CONTINUE TO BE IN GOOD AGREEMENT SHOWING THE  
THUNDERSTORMS DIMINISHING AROUND SUNSET.  
 
TONIGHT: OUR AREA WILL REMAIN BETWEEN ATLANTIC HIGH PRESSURE  
AND TROUGHING INLAND. BOTH THE SYNOPTIC MODELS AND THE CAMS ARE  
IN GOOD AGREEMENT SHOWING LAND AREAS RELATIVELY DRY WHILE THERE  
IS A SMALL RISK OF LATE NIGHT SHOWERS OVER THE COASTAL WATERS.  
TEMPERATURES WILL REMAIN MILD.  
 

 
   
SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/
 
 
FRIDAY THROUGH SUNDAY: OUTSIDE ANY THUNDERSTORMS, HEAT INDEX VALUES  
WILL TOP OUT IN THE 105-109F RANGE AT MANY LOCATIONS, AND HEAT INDEX  
VALUES COULD BRIEFLY TOP OUT AROUND 110F AT SOME LOCATIONS NEAR THE  
COAST/JUST INLAND FROM THE BEACHES AS THE SEA BREEZE PUSHES INLAND.  
 
GUIDANCE DEPICTS ABOVE NORMAL POPS FRIDAY AFTERNOON/EARLY EVENING,  
ESPECIALLY ACROSS SOUTHEAST GA, DUE IN PART TO AN ENHANCED WEAKNESS  
IN THE UPPER RIDGE OVER THE REGION. CAPPED MAXIMUM POPS AROUND 50  
PERCENT ACROSS SE GA, BUT LOCALLY GREATER POPS COULD EVENTUALLY BE  
REQUIRED. IN TYPICAL FASHION FOR MID-JULY, A COUPLE OF PULSE  
THUNDERSTORMS COULD BRIEFLY BECOME SEVERE WITH DAMAGING WIND GUSTS.  
 
SATURDAY AND SUNDAY: PER LATEST GUIDANCE, ONLY SUBTLE CHANGES IN THE  
CONFIGURATION OF THE UPPER RIDGE AND INLAND SURFACE TROUGH COULD  
TRANSLATE TO REDUCED COVERAGE OF DIURNAL/AFTERNOON INTO EVENING  
THUNDERSTORMS AS COMPARED WITH FRIDAY AFTERNOON/EVENING. THE RISK  
FOR BRIEF/ISOLATED DAMAGING WIND GUSTS WILL CONTINUE EACH  
AFTERNOON/EVENING.  
 

 
   
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/
 
 
MODERATE CONFIDENCE THIS PERIOD. THE LOW-LEVEL LEE-SIDE TROUGH LOOKS  
TO PERSIST EARLY IN THE WEEK BEFORE DEEPER TROUGHING LIKELY MOVES  
INTO THE AREA FOR MID WEEK. THIS WILL MEAN INCREASING RAIN CHANCES  
AND LOWER TEMPERATURES, ALTHOUGH HESITATE TO BE TOO AGGRESSIVE WITH  
RAIN CHANCES SO FAR OUT GIVEN THE RARITY OF SUMMERTIME COLD FRONTS  
IN THIS PART OF THE COUNTRY. HEAT INDICES COULD STILL BE NEAR 110  
DEGREES THROUGH MONDAY BUT THE RISK FOR HEAT ADVISORIES WILL LIKELY  
BE OVER STARTING TUESDAY.  
 

 
   
AVIATION /20Z THURSDAY THROUGH TUESDAY/
 
 
18Z TAFS: VFR FOR MUCH OF THE AFTERNOON. THUNDERSTORMS ARE  
EXPECTED ACROSS PORTIONS OF THE AREA FROM LATE THIS AFTERNOON  
THROUGH EARLY THIS EVENING. THE MOST LIKELY TIMES THESE WILL  
OCCUR NEAR THE TAF SITES IS COVERED BY VCTS. THERE IS A HIGH  
LEVEL OF DIFFICULTY DETERMINING PRECISE FLIGHT RESTRICTIONS AND  
TIMING. AMENDMENTS MAY BE MADE LATER BASED ON RADAR TRENDS AND  
POSSIBLY TO ADD TEMPO GROUPS. THE THUNDERSTORMS WILL DISSIPATE  
BY LATER THIS EVENING, ALLOWING VFR TO PREVAIL.  
 
EXTENDED AVIATION OUTLOOK: VFR MUCH OF THIS PERIOD. BRIEF FLIGHT  
RESTRICTIONS AND GUSTY/SHIFTING WINDS COULD OCCUR WITHIN/NEAR  
THUNDERSTORMS, ESPECIALLY DURING THE AFTERNOON/EVENING HOURS.  
THE CHANCE FOR THUNDERSTORMS/ASSOCIATED FLIGHT RESTRICTIONS COULD BE  
GREATEST FRIDAY AFTERNOON/EVENING AND STARTING TUESDAY AS A COLD  
FRONT APPROACHES THE REGION.  
 

 
   
MARINE
 
 
TONIGHT: THE SYNOPTIC PATTERN WILL CONSIST OF HIGH PRESSURE IN  
THE ATLANTIC AND A TROUGH INLAND. THE SURFACE PRESSURE GRADIENT  
WILL BECOME ELEVATED THE FIRST HALF OF THE NIGHT, CAUSING THE  
LOW LEVEL JET TO SET UP. EXPECT S TO SW WINDS UP TO 15-20 KT  
WITH HIGHER GUSTS THROUGH MIDNIGHT. WINDS WILL GRADUALLY EASE  
DURING THE SECOND HALF OF THE NIGHT, AS THE GRADIENT LOWERS  
SLIGHTLY. SEAS WILL BE IN THE 2-4 FT RANGE.  
 
FRIDAY THROUGH TUESDAY: A TYPICAL SUMMER PATTERN FEATURING A TROUGH  
OF LOW PRESSURE INLAND AND OFFSHORE HIGH PRESSURE WILL SUPPORT A  
CONTINUATION OF SOUTH/SOUTHWEST WINDS THROUGH THE PERIOD. WIND  
SPEEDS WILL BE ENHANCED NEAR THE COAST DURING THE AFTERNOON/EVENING  
FROM THE SEA BREEZE AND ACROSS COASTAL WATERS DURING THE OVERNIGHT.  
THROUGH THIS WEEKEND, WINDS SHOULD REMAIN CAPPED AROUND 20 KNOTS AND  
SEAS SHOULD;D AVERAGE 2-4 FEET, BELOW SMALL CRAFT ADVISORY LEVELS.  
EARLY NEXT WEEK, A COLD FRONT WILL APPROACH THE REGION, AND THE  
PROBABILITY FOR LOCAL SCA CONDITIONS COULD INCREASE.  
 

 
   
CHS WATCHES/WARNINGS/ADVISORIES
 
 
GA...NONE.  
SC...NONE.  
MARINE...NONE.  
 

 
 

 
NEAR TERM...  
SHORT TERM...  
LONG TERM...RJB  
AVIATION...  
MARINE...  
 
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