101  
FXUS62 KCHS 301803  
AFDCHS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON SC  
203 PM EDT WED JUL 30 2025  
   
SYNOPSIS
 
 
ATLANTIC HIGH PRESSURE PREVAILS OFFSHORE THROUGH THE REST OF  
THE WORK WEEK, A TROUGH OF LOW PRESSURE WILL CONTINUE TO PRESS  
INLAND. A COLD FRONT MAY STALL NEARBY THIS WEEKEND AND PROMOTE  
HEAVY TO EXCESSIVE RAINFALL ACROSS THE REGION.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
INSTABILITY IS SLOWLY BUILDING OVER THE AREA THIS AFTERNOON.  
ISOLATED TO SCATTERED CONVECTION CONTINUES TO PERCOLATE ACROSS  
PARTS OF THE CHARLESTON TRI-COUNTY ALONG SEVERAL MESOSCALE  
BOUNDARIES, BUT COVERAGE SHOULD SLOWLY RAMP UP AND REFOCUS  
INLAND AS THE AFTERNOON PROGRESSES. NBM POPS AROUND 70% ACROSS  
THE INTERIOR MAY BE A BIT HIGH BASED ON SOME OF THE LATEST CAMS,  
BUT THESE WERE MOSTLY MAINTAINED AS IT DOES NOT REALLY IMPACT  
OUR LOCAL MESSAGING THAT THE TSTM MAIN RISKS FOR THIS  
AFTERNOON/EVENING CONTINUE TO CENTER ON LOCALLY HEAVY  
RAINFALL/MINOR FLOODING AND A FEW STRONG TSTMS. NOT UNCOMMON FOR  
DEEP SUMMER, AN ISOLATED SEVERE TSTM WITH DAMAGING WINDS FROM  
WET MICROBURSTS CAN NOT BE COMPLETELY RULED OUT. CONVECTION WILL  
SLOWLY WIND DOWN THROUGH THE EVENING HOURS, BUT LINGERING  
OUTFLOW BOUNDARIES AND WARM/MOIST CONDITIONS COULD SUPPORT SOME  
DEGREE OF CONVECTION OVERNIGHT, SIMILAR TO WHAT OCCURRED LAST  
NIGHT. LOWS TONIGHT WILL RANGE FROM THE MID 70S WELL INLAND TO  
THE UPPER 70S/LOWER 80S AT THE COAST AND BEACHES.  
 
AS FOR THE HEAT ADVISORY, HEAT INDICES ARE NEARING THE 108 MARK  
ACROSS PARTS OF SOUTHEAST GEORGIA UP INTO THE BEAUFORT COUNTY  
AREA. EVEN UP IN CHARLESTON WHERE CONVECTION HAS BEEN OFF AND ON  
FOR THE PAST FEW HOURS, SOME LOCATIONS ARE ALREADY SEEING HEAT  
INDICES NEAR 110. THE HEAT ADVISORY WILL REMAIN IN EFFECT UNTIL  
8 PM AS IT IS CURRENTLY DEFINED, BUT SOME CLEARING OF COUNTIES  
MAY BE NEEDED LATER THIS AFTERNOON AS CONVECTION EXPANDS.  
 

 
   
SHORT TERM /THURSDAY THROUGH SATURDAY/
 
 
AS THIS SUBTROPICAL RIDGE WEAKENS, MULTIPLE SHORTWAVES ALOFT  
WILL CARVE OUT AN UPPER-LVL TROUGH ACROSS THE EASTERN CONUS. AT  
THE SURFACE, A REASONABLY STRONG COLD FRONT FOR EARLY AUGUST  
WILL START TO PUSH INTO THE REGION AT THE LEADING EDGE OF THIS  
AFOREMENTIONED UPPER-LVL TROUGH. AMPLE MOISTURE AND INSTABILITY  
WILL PROMOTE HEAVY TO EXCESSIVE RAINFALL IN SHOWERS AND/OR  
THUNDERSTORMS THAT COULD CAUSE LOCALIZED FLASH FLOODING. IN  
ADDITION, WPC HAS PLACED THE REGION UNDER A SLIGHT RISK FOR  
EXCESSIVE RAINFALL ON FRIDAY AND SATURDAY. IN REGARD TO  
TEMPERATURES, EXPECT HIGHS TO REACH INTO THE MID TO UPPER 90S ON  
THURSDAY AND FRIDAY WITH DEWPOINTS RANGING IN THE MID TO UPPER  
70S. A HEAT ADVISORY WAS ISSUED FOR TOMORROW (11AM TO 8PM  
EDT)FOR COUNTIES ALONG AND EAST OF I-95 AS HEAT INDICES ARE  
EXPECTED TO REACH INTO THE 108 TO 112 DEGREES RANGE. FRIDAY  
COULD WARRANT ANOTHER HEAT ADVISORY, HOWEVER SHOWERS AND/OR  
THUNDERSTORMS MIGHT LIMIT AFTERNOON HEATING. AS THIS COLD FRONT  
CONTINUES TO DROP SOUTHEASTWARD ACROSS THE REGION, TEMPERATURES  
WILL FINALLY COOL DOWN ON SATURDAY, WITH HIGHS ONLY REACHING  
INTO THE MID 80S TO LOW 90S UNDER CLOUDY SKIES. THIS WILL BE  
ENOUGH TO LIMIT HEATING SATURDAY, AND AN ADDITIONAL HEAT  
ADVISORY MAY NOT BE NEEDED.  
 

 
   
LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/
 
 
THIS WET AND UNSETTLED PATTERN WILL CONTINUE THROUGH THE EARLY  
NEXT WEEK AS THIS COLD FRONT STALLS NEARBY AND MEANDERS ALONG  
THE COASTLINE. WITH PWATS 2.0+ INCHES AND DECENT INSTABILITY  
STICKING AROUND, SCATTERED CONVECTION ACROSS THE REGION SHOULD  
BE MAINTAINED. PERIODS OF LOCALLY HEAVY RAINFALL WILL BE  
POSSIBLE WITHIN THESE SHOWERS AND/OR THUNDERSTORMS THAT TRACK  
OVER AN AREA FOR AN EXTENDED PERIOD OF TIME. CONFIDENCE STILL  
REMAINS LOW IF THE FLASH FLOODING WILL BE ENOUGH TO WARRANT A  
FLOOD WATCH. ADDITIONALLY, WPC CONTINUES TO SHOW 3 TO 5 INCHES  
OF RAINFALL ACROSS OUR AREA ON THE 7-DAY QPF FORECAST, WITH THE  
MAJORITY OF THESE VALUES FALLING SATURDAY THROUGH MONDAY. ON A  
POSITIVE NOTE, THIS PATTERN WILL ALLOW FOR A REFRESHING CHANGE  
OF COOLER TEMPERATURES THROUGH EARLY NEXT WEEK WITH HIGHS ONLY  
REACHING INTO THE LOW TO MID 80S.  
 

 
   
AVIATION /16Z WEDNESDAY THROUGH SUNDAY/
 
 
30/18Z TAF DISCUSSION:  
KCHS/KJZI: TSTMS WILL MEANDER NEAR KCHS FOR THE NEXT FEW HOURS.  
VCTS WAS HIGHLIGHTED AT BOTH TERMINALS THROUGH MID-AFTERNOON  
WITH TEMPO FOR DIRECT IMPACTS AT KCHS ROUGHLY THROUGH 20-21Z.  
VFR SHOULD PREVAIL FOR THE REMAINDER OF THE NIGHT, ALTHOUGH WITH  
MOIST/HUMID CONDITIONS HOLDING IN PLACE THROUGH SUNRISE, AN  
ISOLATED NOCTURNAL SHOWER/TSTM CAN NOT BE COMPLETELY RULED OUT.  
 
KSAV: THE TERMINAL WILL REMAIN DRY THROUGH THE REMAINDER OF THE  
AFTERNOON WITH CONVECTION EXPECTED TO CONCENTRATE TO THE WEST.  
SOME ACTIVITY COULD MEANDER INTO THE TERMINAL LATER THIS  
EVENING, WHICH WAS HANDLED WITH A VCTS 00-04Z. VFR SHOULD PREVAIL  
FOR THE REMAINDER OF THE NIGHT, ALTHOUGH WITH MOIST/HUMID  
CONDITIONS HOLDING IN PLACE THROUGH SUNRISE, AN ISOLATED  
NOCTURNAL SHOWER/TSTM CAN NOT BE COMPLETELY RULED OUT.  
 
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
 
 
TONIGHT: SOUTHERLY WINDS WILL VEER TO THE SOUTHWEST OVERNIGHT.  
SPEEDS WILL REMAIN LESS THAN 15 KT WITH SEAS 1-3 FT.  
 
THURSDAY THROUGH SUNDAY: EXPECT SOUTHERLY WINDS AT 10 TO 15 KT  
THROUGH FRIDAY, WITH WINDS TURNING TO THE NORTHEAST OVER THE  
WEEKEND AS A REASONABLY STRONG COLD FRONT FOR EARLY AUGUST  
STALLS NEARBY OVER THE WEEKEND. IT COULD BECOME GUSTY OVER THE  
WEEKEND (MAINLY ON SUNDAY AFTERNOON) ACROSS THE NEARSHORE SOUTH  
CAROLINA WATERS AS THE GRADIENT PINCHES BEHIND THE COLD FRONT.  
EXPECT SEAS TO BE 2 TO 3 FT, AND THEN BEGIN TO BUILD 3 TO 5 FT  
ON SUNDAY (MAINLY ACROSS SOUTH CAROLINA NEARSHORE WATERS).  
OTHERWISE, NO MARINE CONCERNS.  
 

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

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

 
 

 
 
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