798  
FXUS62 KCHS 271025  
AFDCHS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON SC  
625 AM EDT SUN JUL 27 2025  
   
SYNOPSIS
 
 
ATLANTIC HIGH PRESSURE WILL PREVAIL EARLY THIS WEEK, WHILE A  
TROUGH OF LOW PRESSURE RESIDES INLAND. A COLD FRONT COULD  
APPROACH THE REGION LATE WEEK.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
TODAY: A SIMILAR SET-UP IS ON TAP FOR TODAY WITH A PERSISTENT STRONG  
UPPER LEVEL RIDGE (H5 597 DAM) CENTERED OVER THE DEEP SOUTH. AT  
THE SURFACE, HIGH PRESSURE LIES TO THE SOUTH IN ADDITION TO A  
WEAK TROUGH OVER THE APPALACHIANS. STRONG SUBSIDENCE AND MID-  
LEVEL DRY AIR WILL SUPPRESS CONVECTION, WITH NO MENTIONABLE POPS  
IN THE FORECAST. THERE IS A VERY SMALL CHANCE A LIGHT SHOWER  
COULD DEVELOP ALONG THE SEA BREEZE LATER THIS AFTERNOON, BUT  
STRONG DOWNWARD VERTICAL MOTION WILL KEEP ANY DEVELOPMENT BRIEF.  
SIMILAR TO SATURDAY, ANOTHER HOT DAY IS FORECAST WITH MOSTLY  
SUNNY SKIES WITH THE EXCEPTION OF A FEW SHALLOW CUMULUS  
OVERHEAD.  
 
ONCE AGAIN THE MAIN CONCERN WILL BE THE EXCESSIVE HEAT AS HIGH  
TEMPERATURES PEAK BETWEEN 98-102 DEGREES MOST PLACES. EVEN  
ACROSS "COOLER" LOCATIONS, SUCH AS ALONG THE IMMEDIATE COAST AND  
THE BEACHES, HIGHS WILL PEAK IN THE MID 90S. SEE THE CLIMATE  
SECTION BELOW FOR CLIMATE SITES IN JEOPARDY OF BREAKING RECORD  
HIGHS AND/OR RECORD HIGH MINS. LIGHT, WESTERLY SURFACE FLOW WILL  
RESULT IN A SEMI-PINNED SEA BREEZE, WITH SOME INLAND  
PROGRESSION LATER IN THE AFTERNOON WHICH WILL ADVECT UPPER 70 TO  
NEAR 80 DEGREE DEW POINTS INLAND. THIS WILL RESULT IN MAXIMUM  
HEAT INDICES RANGING BETWEEN 112-116 ALONG THE COASTAL  
LOCATIONS, AND 108-112 FURTHER INLAND. AS A RESULT, AN EXTREME  
HEAT WARNING IS IN EFFECT FOR ALL COASTAL ZONES ACROSS SOUTHEAST  
SOUTH CAROLINA AND SOUTHEAST GEORGIA INCLUDING BERKELEY,  
DORCHESTER, INLAND COLLETON, INLAND JASPER, AND INLAND CHATHAM  
COUNTIES, AND A HEAT ADVISORY IS IN EFFECT FOR THE REMAINING  
COUNTIES/ZONES.  
 
TONIGHT: ANOTHER QUIET, BUT HOT AND MUGGY NIGHT EXPECTED. LITTLE  
RELIEF FROM THE HEAT IS EXPECTED AS MINIMUM TEMPERATURES ACROSS  
THE INLAND COUNTIES ONLY DIP DOWN INTO THE 78-80 DEGREE RANGE.  
CLOSER TO THE COAST, MIN TEMPS WILL REMAIN IN THE LOWER 80S.  
ONCE AGAIN, HEAT ADVISORY/EXTREME HEAT HEADLINES WILL CONTINUE  
THROUGH THE NIGHT GIVEN THE LACK OF RECOVERY FROM THE WARM  
OVERNIGHT TEMPERATURES.  
 

 
   
SHORT TERM /MONDAY/
 
 
THE ONGOING HEAT WAVE WILL CONTINUE THROUGH THE FIRST PART OF THE  
WEEK. AN EXTREME HEAT WATCH/WARNING REMAINS IN PLACE FOR MONDAY,  
WITH THE POTENTIAL FOR ADDITIONAL HEAT HEADLINES TUESDAY AND  
POSSIBLY WEDNESDAY.  
 
THE REGION WILL BECOME POSITIONED ON THE EASTERN PERIPHERY OF AN  
EXPANSIVE RIDGE CENTERED OVER THE SOUTH CENTRAL U.S MONDAY INTO MID  
WEEK, WITH MODELS CONSISTENT IN SHORTWAVE ENERGY DROPPING SOUTH  
ACROSS THE REGION. THE SURFACE PATTERN WILL LARGELY BE CHARACTERIZED  
BY HIGH PRESSURE OFFSHORE AND AN INLAND TROUGH.  
 
HOT AND HUMID CONDITIONS WILL BE THE RULE THROUGH THE PERIOD. MONDAY  
LOOKS TO BE THE HOTTEST WITH HIGHS FORECAST TO REACH AROUND 100F IN  
MANY PLACES. THESE VALUES ARE WITHIN A FEW DEGREES OF RECORDS (SEE  
CLIMATE SECTION BELOW). THE PROBABILITY FOR HEAT INDICES OF 113 OR  
GREATER (EXTREME HEAT WARNING CRITERIA) IS HIGHEST OVER THE  
CHARLESTON QUAD-COUNTY AND SOUTH ALONG THE SC AND GA COAST, SO THE  
ONGOING WARNING REMAINS IN PLACE. OPTED TO MAINTAIN THE WATCH  
ELSEWHERE FOR NOW AS IT APPEARS MORE BORDERLINE. THE HEAT REMAINS A  
CONCERN THROUGH WEDNESDAY. ADDITIONAL HEAT HEADLINES ARE POSSIBLE,  
BUT SEEMS MORE SOLIDLY IN THE ADVISORY CRITERIA VERSUS WARNING.  
 
THE POTENTIAL FLY IN THE OINTMENT WOULD BE ANY CONVECTION THAT  
DEVELOPS. ON MONDAY, IT LOOKS LIKE ANY ACTIVITY THAT MOVES IN WOULD  
BE LATER IN THE DAY. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS  
ARE THEN IN THE FORECAST BOTH TUESDAY AND WEDNESDAY AFTERNOON/  
EVENING. IT'S WORTH NOTING THAT ANY STORMS THAT DEVELOP HAVE THE  
POTENTIAL TO BE STRONG GIVEN THE AIRMASS IN PLACE, EVEN WITH  
RELATIVELY WEAK SHEAR. DAMAGING WIND GUSTS WOULD BE THE PRIMARY  
THREAT.  
 

 
   
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/
 
 
PERSISTENT MID LEVEL RIDGE WILL FINALLY WEAKEN AS WE HEAD INTO LATE  
WEEK AND THE WEEKEND AS A LARGER SCALE TROUGH SHIFTS INTO THE  
NORTHEASTERN U.S. AND A COLD FRONT APPROACHES THE REGION. IT'S  
UNCLEAR HOW MUCH SOUTHWARD PROGRESS THE FRONT MAKES, BUT REGARDLESS,  
THERE WILL BE SOME REPRIEVE FROM THE OPPRESSIVE HEAT BY THE WEEKEND  
AND INCREASED RAIN CHANCES.  
 

 
   
AVIATION /12Z SUNDAY THROUGH THURSDAY/
 
 
27/12Z TAF DISCUSSION:  
KCHS/KJZI/KSAV: VFR THROUGH SUNDAY NIGHT.  
 
EXTENDED AVIATION FORECAST: PREVAILING VFR. BRIEF FLIGHT  
RESTRICTIONS ARE POSSIBLE IN AFTERNOON SHOWERS/THUNDERSTORMS THIS  
WEEK.  
 

 
   
MARINE
 
 
TODAY AND TONIGHT: WESTERLY WINDS IN THE MORNING WILL SHIFT OUT  
OF THE SOUTH-SOUTHWEST BY THE AFTERNOON WITH SPEEDS AVERAGING  
5-10 KT. SEAS WILL RANGE FROM 1-2 FT.  
 
MONDAY THROUGH FRIDAY: NO MARINE CONCERNS ARE ANTICIPATED THROUGH  
THE WEEK. GENERALLY EXPECT SOUTHERLY FLOW WITH SPEEDS LESS THAN 15  
KNOTS. SEAS WILL AVERAGE 1-3 FEET.  
 

 
   
CLIMATE
 
 
RECORD HIGH TEMPERATURES:  
 
JULY 27:  
KCHS: 100/2005  
KSAV: 100/2010  
 
JULY 28:  
KSAV: 102/1949  
 
RECORD HIGH MINIMUM TEMPERATURES:  
 
JULY 27:  
KCHS: 80/2014  
KSAV: 80/1885  
 
JULY 28:  
KCHS: 80/2016  
KCXM: 83/1999  
KSAV: 81/1878  
 
JULY 29:  
KCHS: 80/2016  
 
JULY 30:  
KCHS: 81/2016  
KSAV: 81/1878  
 
JULY 31:  
KCHS: 80/2022  
KSAV: 80/2010  
 
AUGUST 1:  
KSAV: 79/2020  
 

 
   
CHS WATCHES/WARNINGS/ADVISORIES
 
 
GA...HEAT ADVISORY UNTIL 10 AM EDT MONDAY FOR GAZ087-088-099>101-  
114>116-137-138-140.  
EXTREME HEAT WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING  
FOR GAZ087-088-099>101-114>116-137-138-140.  
HEAT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR GAZ117>119-139-  
141.  
EXTREME HEAT WARNING FROM 10 AM THIS MORNING TO 8 PM EDT  
MONDAY FOR GAZ117>119-139-141.  
SC...HEAT ADVISORY UNTIL 10 AM EDT MONDAY FOR SCZ040-042.  
EXTREME HEAT WATCH FROM MONDAY MORNING THROUGH MONDAY EVENING  
FOR SCZ040-042.  
HEAT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR SCZ043>045-  
047>052.  
EXTREME HEAT WARNING FROM 10 AM THIS MORNING TO 8 PM EDT  
MONDAY FOR SCZ043>045-047>052.  
MARINE...NONE.  
 

 
 

 
 
NEAR TERM...BRS  
SHORT TERM...ETM  
LONG TERM...ETM  
AVIATION...BRS/ETM  
MARINE...BRS/ETM  
 
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