944  
FXUS62 KCHS 301120  
AFDCHS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON SC  
720 AM EDT WED JUL 30 2025  
   
SYNOPSIS
 
 
ATLANTIC HIGH PRESSURE WILL PREVAIL EAST OF THE AREA FOR MOST  
OF THE WEEK, ALONG WITH A TROUGH OF LOW PRESSURE INLAND. A COLD  
FRONT MAY STALL NEAR THE AREA THIS WEEKEND.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
CONVECTION HAS RE-FIRED OVER PORTIONS OF COLLETON, DORCHESTER  
AND CHARLESTON COUNTIES. EXPECT SOME AREAS WILL GET 1-2 INCHES  
OR MORE OF RAINFALL IN THE NEXT FEW HOURS. MAY NEED TO ISSUE  
FLOOD ADVISORIES. THIS CONVECTION APPEARS TO HAVE FORMED WITHIN  
THE INLAND TROUGH OF LOW PRESSURE, ESPECIALLY OVER AREAS THAT  
DIDN'T RECEIVE CONVECTION YESTERDAY, AND THEREFORE REMAIN  
UNSTABLE. CAMS GENERALLY SHOW SCATTERED CONVECTION WILL  
CONTINUE, ESPECIALLY OVER OUR SC ZONES, THROUGH THE REST OF THE  
EARLY MORNING HOURS WITHIN THE AREA OF LOW LEVEL CONVERGENCE  
ASSOCIATED WITH THE SURFACE TROUGH.  
 
BY AFTER SUNRISE AND INTO THIS AFTERNOON: CONVECTION SHOULD DIE  
DOWN SOME AFTER SUNRISE, BUT THEN REDEVELOP BY AFTERNOON WITH  
STRONG AFTERNOON HEATING AND CAPE VALUES 2000-2500 J/KG. SOME  
STORMS COULD BECOME STRONG, ESPECIALLY WHERE BOUNDARY COLLISIONS  
OCCUR. GIVEN RELATIVELY SLOW STORM MOTIONS, ALONG WITH PWS OVER  
2 INCHES, LOCALLY HEAVY RAINFALL AND MINOR FLOODING OF LOW-LYING  
AREAS WILL AGAIN BE POSSIBLE THIS AFTERNOON. DESPITE THE  
INCREASED RAIN THREAT, HAVE CONTINUED THE HEAT ADVISORY FOR THIS  
AFTERNOON, GENERALLY ALONG THE SC COAST AND ACROSS MUCH OF OUR  
GA ZONES WITH MAX HEAT INDICES OF 108-112. OF COURSE, CONVECTION  
COULD DISRUPT TEMPERATURES AND HUMIDITY, WHICH COULD IMPACT THE  
HEAT ADVISORY.  
 
TONIGHT: CONVECTION IS EXPECTED TO DECREASE IN COVERAGE.  
HOWEVER, GIVEN AMPLE MOISTURE AND PRESENCE OF INSTABILITY, IT IS  
LIKELY THAT AT LEAST ISOLATED CONVECTION WILL PERSIST MUCH OF  
THE NIGHT.  
 

 
   
SHORT TERM /THURSDAY THROUGH SATURDAY/
 
 
THURSDAY AND FRIDAY: SUBTROPICAL RIDGE BEGINS TO WEAKEN BY LATE  
WEEK, AS MULTIPLE SHORTWAVES ALOFT CARVE OUT A LONGER WAVE TROUGH  
ACROSS THE EASTERN CONUS. THIS WILL SUPPORT A CONTINUED RISK FOR  
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EACH  
AFTERNOON/EVENING. IN REGARD TO TEMPERATURES, LOOK FOR HIGHS TO  
REMAIN IN THE MID TO UPPER 90S, WITH PERHAPS A FEW LOCATIONS ACROSS  
SOUTHEASTERN GEORGIA FLIRTING WITH 100 DEGREES. SIMILAR TO DAYS  
PAST, WILL SEE HEAT INDICES PEAK BETWEEN 105-108 DEGREES INLAND TO  
108-112 DEGREES ALONG/EAST OF I-95 PRIOR TO THE ONSET OF ANY  
CONVECTION. ADDITIONAL HEAT ADVISORIES MAY BE NEEDED, BUT THESE WILL  
LARGELY BE DRIVEN BY THE TIMING AND EXTENT OF AFTERNOON CONVECTION -  
SO STAY TUNED FOR FUTURE UPDATES!  
 
SATURDAY: BROAD UPPER LEVEL TROUGH AND ITS ATTENDANT SFC COLD FRONT  
CONTINUE TO SAG SOUTHEASTWARD ACROSS THE REGION FRIDAY NIGHT,  
RESULTING IN A FAIRLY WET AND UNSETTLED PATTERN OVER THE WEEKEND.  
WHILE SHOWERS AND STORMS WILL LIKELY BE ONGOING SATURDAY MORNING,  
EXPECT THE BETTER CHANCES TO ARRIVE DURING THE AFTERNOON HOURS AS  
INSTABILITY AND MOISTURE INCREASE. TEMPERATURES DURING THIS TIME  
WILL ALSO BE NOTABLY COOLER, AS HIGHS ONLY RISE INTO THE MID 80S TO  
LOWER 90S UNDER CLOUDY SKIES.  
 

 
   
LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/
 
 
DREARY CONDITIONS CONTINUE SUNDAY AND MONDAY AS THE AFOREMENTIONED  
FRONT STALLS ALONG THE COAST. WITH PWATS GREATER THAN 2 INCHES,  
COULD CERTAINLY SEE PERIODS OF LOCALLY HEAVY RAINFALL, WHICH MAY  
RESULT IN FLASH FLOODING. AS NOTED IN THE PREVIOUS DISCUSSION,  
CONFIDENCE STILL REMAINS TOO LOW AT THIS TIME TO DETERMINE IF THE  
RISK FOR FLASH FLOODING WILL BE WIDESPREAD ENOUGH TO WARRANT A FLOOD  
WATCH. DO THINK IT'S WORTH NOTING, HOWEVER, THAT WPC'S LATEST 7 DAY  
QPF FORECAST DOES HIGHLIGHT TOTALS POTENTIALLY REACHING 3 TO 5  
INCHES ACROSS OUR AREA, WITH A BULK OF THOSE VALUES EXPECTED TO FALL  
OVER A 3 DAY PERIOD (SATURDAY THROUGH MONDAY). CERTAINLY SOMETHING  
TO KEEP AN EYE ON IN THE COMING DAYS, ESPECIALLY FOR THOSE FOLKS WHO  
HAVE OUTDOOR PLANS! OTHERWISE, LOOK FOR SEASONALLY COOL TEMPERATURES  
TO PREVAIL FOR THE REMAINDER OF THE EXTENDED PERIOD.  
 

 
   
AVIATION /11Z WEDNESDAY THROUGH SUNDAY/
 
 
KCHS AND KJZI: EXPECT CONVECTION TO REDEVELOP THIS AFTERNOON  
THEN PUSH INLAND LATER IN THE AFTERNOON/EVENING. FLIGHT  
RESTRICTIONS POSSIBLE WITH ANY SHOWERS/THUNDERSTORMS THIS  
AFTERNOON. EXPECT A RETURN TO VFR CONDITIONS AFTER 00Z 31 JULY.  
 
KSAV: VFR CONDITIONS LIKELY TO PREVAIL THROUGH THIS MORNING. BY  
AFTERNOON, SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ARE  
EXPECTED. SO, HAVE KEPT TEMPO FOR CONVECTION THROUGH MID/LATE  
AFTERNOON WITH FLIGHT RESTRICTIONS POSSIBLE. EXPECT RETURN TO  
VFR AFTER 00Z 31 JULY.  
 
EXTENDED AVIATION FORECAST: THE RISK FOR FLIGHT RESTRICTIONS DUE TO  
SHOWERS/TSTMS WILL PERSIST EACH AFTERNOON/EVENING WITH CHANCES  
RAMPING UP OVER THE WEEKEND.  
 

 
   
MARINE
 
 
NO HIGHLIGHTS ARE EXPECTED THROUGH TONIGHT. ATLANTIC HIGH  
PRESSURE WILL REMAIN CENTERED SOUTHEAST OF THE WATERS, WITH AN  
INLAND TROUGH OF LOW PRESSURE. GENERALLY SOUTHERLY WINDS OF 5-15  
KTS, STRONGEST NEAR THE COAST IN THE AFTERNOON AS THE SEABREEZE  
DEVELOPS. SEAS 2 TO 3 FEET, HIGHEST BEYOND 20 NM OFFSHORE OF THE  
GA WATERS. SCATTERED MAINLY MORNING AND LATE NIGHT SHOWERS AND  
THUNDERSTORMS.  
 
EXTENDED MARINE: SOUTHERLY WIND REGIME WILL PREVAIL THROUGH FRIDAY.  
WINDS WILL BEGIN TO TURN NORTHEAST OVER THE WEEKEND AS A COLD FRONT  
STALLS OUT NEAR THE AREA. WINDS WILL GENERALLY REMAIN 15 KT OR LESS  
THROUGH THE PERIOD, ALTHOUGH WINDS MAY GET AS HIGH AS 15- 20 KT OVER  
THE WEEKEND ACROSS MAINLY THE SOUTH CAROLINA WATERS AS THE GRADIENT  
PINCHES A BIT BEHIND THE COLD FRONT.  
 

 
   
CLIMATE
 
 
RECORD HIGH MINIMUM TEMPERATURES:  
 
JULY 30:  
KCHS: 81/2016  
KCXM: 83/2016  
 
JULY 31:  
KCHS: 80/2022  
KSAV: 80/2010  
 
AUGUST 1:  
KCHS: 81/1999  
KSAV: 79/2020  
 

 
   
CHS WATCHES/WARNINGS/ADVISORIES
 
 
GA...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING  
FOR GAZ099>101-114>119-137>141.  
SC...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING  
FOR SCZ047>052.  
MARINE...NONE.  
 

 
 

 
 
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