376  
FXUS62 KCHS 302339  
AFDCHS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON SC  
739 PM EDT FRI MAY 30 2025  
   
SYNOPSIS
 
 
A COLD FRONT WILL SWEEP THROUGH OUR AREA TONIGHT. HIGH PRESSURE  
WILL BUILD IN OVER THE WEEKEND AND PREVAIL THROUGH THE MIDDLE  
OF NEXT WEEK.  
 

 
   
NEAR TERM /UNTIL 6 AM SATURDAY MORNING/
 
 
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR THE ENTIRE  
FORECAST AREA THROUGH 11PM THIS EVENING.  
 
A LARGE UPPER TROUGH WITH AN EMBEDDED SHORTWAVE WILL SLIDE  
TOWARD THE EAST COAST. A COLD FRONT IS EXPECTED TO DROP  
SOUTHEAST INTO OUR FORECAST AREA LATE THIS EVENING AND MOVE  
OFFSHORE SHORTLY AFTER MIDNIGHT. REGIONAL RADARS CURRENTLY SHOW  
A LINE OF CONVECTION NOT TOO FAR UPSTREAM, ACROSS THE SOUTH  
CAROLINA MIDLANDS, WORKING ITS WAY EAST SOUTHEAST TOWARD THE  
LOCAL CWA. WINDS WILL BE RELATIVELY PARALLEL TO THE FRONT BY  
THE TIME IT REACHES OUR AREA, SO WE STILL EXPECT SOME WEAKENING  
AT LEAST ALONG THE SOUTHERN PORTION OF THE LINE HEADED INTO  
SOUTHEAST GEORGIA. ON THE OTHER HAND, CONVECTIVE INDICES ARE  
RATHER FAVORABLE WITH 0-6 KM BULK SHEAR AROUND 40 KT AND LLVL  
LAPSE RATES AROUND 7-8C, WHILE CAPE IS SOMEWHAT LIMITED AROUND  
1500 J/KG. DAMAGING WINDS WOULD BE THE PRIMARY THREAT, SUPPORTED  
BY CAMS WHICH HAVE BEEN CONSISTENTLY SHOWING BOWING SEGMENTS IN  
SIMULATED REFLECTIVITY MOVING ACROSS PORTIONS OF THE SOUTHEAST  
SOUTH CAROLINA COUNTIES. LIFTED INDICES OF -6C WOULD SUPPORT  
SOME HAIL RISK, AND CAN'T COMPLETELY RULE OUT AN ISOLATED  
TORNADO. QUICK-MOVING STORMS WILL KEEP HEAVIER RAINS SHORT-  
LIVED, THUS WE DO NOT ANTICIPATE WIDESPREAD FLOODING ISSUES.  
 
STORMS WILL QUICKLY TRACK ACROSS THE AREA MOVING OFFSHORE AROUND  
9-10 PM. COOLER, DRIER AIR WILL SPREAD IN FROM THE WEST OVERNIGHT,  
NOTED BY DEWPOINTS DROPPING INTO THE MID TO UPPER 50S. GOOD  
RADIATIONAL COOLING CONDITIONS ARE EXPECTED LATE TONIGHT/EARLY  
THIS MORNING WITH CLEARING SKIES, AND WINDS NOT NECESSARILY  
CALM, BUT BECOMING LIGHT. OVERNIGHT LOW TEMPERATURES WILL DIP  
INTO THE UPPER 50S INLAND AND LOW TO MID 60S CLOSER TO THE  
COAST. ALONG THE BEACHES AND DOWNTOWN CHARLESTON, TEMPERATURES  
COULD REMAIN MILD, IN THE UPPER 60S.  
 

 
   
SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/
 
 
SATURDAY: NOW ON THE BACKSIDE OF THE UPPER LEVEL TROUGH AXIS AND  
SURFACE FRONT, MARGINALLY COOLER TEMPERATURES WILL RESULT IN  
AFTERNOON HIGHS IN THE LOWER TO MID 80S, WARMEST ALONG THE COAST.  
WINDS WILL REMAIN OUT OF THE WEST-NORTHWEST SUSTAINED 10 TO 15 MPH  
WITH GUSTS INTO THE LOWER 20S, WITH DEWPOINTS IN THE UPPER 50S TO  
LOWER 60S. WINDS WEAKEN OVERNIGHT AS A COLD FRONT MAY MOVE IN FROM  
THE NORTH, POTENTIALLY STALLING ACROSS THE SOUTH CAROLINA  
LOWCOUNTRY, WITH OVERNIGHT LOWS IN THE LOWER 60S TO UPPER 60S,  
WARMEST ALONG THE COAST.  
 
SUNDAY: UPPER LEVEL TROUGH DEEPENS AHEAD OF AN APPROACHING  
SHORTWAVE, WITH THE AFOREMENTIONED FRONT PUSHING NORTH THROUGHOUT  
THE DAY. THIS WILL RESULT IN TEMPERATURES AGAIN IN THE MID TO UPPER  
80S, WARMEST ALONG THE COAST. THE SHORTWAVE MOVES ACROSS THE AREA  
DURING THE EVENING AND OVERNIGHT HOURS, BRINGING OUR NEXT CHANCES  
FOR SHOWERS AND THUNDERSTORMS. NBM HAS VERY LOW AND SCATTERED POPS  
FOR THE REGION AS THIS SHORTWAVE MOVES THROUGH, WHICH ADMITTEDLY  
MATCHES UP WITH WHAT THE MODELS ARE SUGGESTING, BUT WOULD NOT BE  
SURPRISED TO SEE THAT INCREASE OVER THE NEXT COUPLE MODEL  
CYCLES.  
 
MONDAY: THE TROUGH AXIS WILL BE PUSHING OFF INTO THE ATLANTIC  
THROUGHOUT THE MORNING HOURS, WITH A SURFACE HIGH PRESSURE MOVING  
DOWN INTO THE REGION THROUGHOUT THE DAY. AN AFTERNOON SEA BREEZE MAY  
SPARK OFF A ROUND OF SHOWERS AND THUNDERSTORMS, BUT AS WE ARE UNDER  
THE AREA OF SUBSIDENCE ALOFT, PROBABILITIES REMAIN LARGELY BELOW 20  
PERCENT. AFTERNOON HIGHS IN THE MID 80S TO LOWER 90S ARE EXPECTED,  
WARMEST ACROSS SOUTHEASTERN GEORGIA.  
 

 
   
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
 
 
UPPER LEVEL RIDGING OCCURS BEHIND THE EXITING TROUGH, BRINGING DRY  
CONDITIONS BACK TO THE AREA. WITH MID TO UPPER LEVEL GEOPOTENTIAL  
HEIGHTS REMAINING ON THE HIGHER SIDE OF CLIMATOLOGY, THOUGH WELL  
BELOW THE 90TH PERCENTILE, NORMAL TO ABOVE NORMAL TEMPERATURES ARE  
EXPECTED WITH DAILY HIGHS IN THE UPPER 80S TO LOWER 90S. CHANCES FOR  
RAINFALL RETURN THURSDAY AFTERNOON AND EVENING AS MID-LEVEL MOISTURE  
INCREASES.  
 

 
   
AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
 
 
ASIDE FROM ANY LINGERING SHOWERS/STORMS THAT MAY BE CAPABLE OF BRIEF  
MVFR VISBYS AT BEST FOR THE NEXT HOUR MAYBE TWO, VFR CONDITIONS  
ARE EXPECTED FOR THE REMAINDER OF THE TAF PERIOD. WINDS WILL  
TURN FROM CURRENT SOUTHWESTERTLY TO NORTHWESTERLY BY THE EARLY  
OVERNIGHT PERIOD, DECREASING BRIEFLY BEFORE BECOMING SUSTAINED  
NEAR 10 KNOTS SATURDAY MORNING.  
 
EXTENDED AVIATION OUTLOOK: NO AVIATION CONCERNS WITH GREATER THAN  
50% CONFIDENCE.  
 

 
   
MARINE
 
 
TONIGHT: A COLD FRONT WILL PUSH OFFSHORE LATE TONIGHT, SHIFTING  
WINDS OUT OF THE WEST NORTHWEST. MARINERS SHOULD BE AWARE THAT LATE  
THIS EVENING, A LINE OF THUNDERSTORMS WILL BE QUICKLY PUSHING  
OFFSHORE AHEAD OF THE FRONT, SOME OF WHICH COULD BE STRONG TO  
SEVERE. STRONG/DAMAGING WIND GUSTS AND HAIL ARE POSSIBLE WITHIN  
STRONGER STORMS. A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED FOR  
ALL MARINE ZONES THROUGH 11PM THIS EVENING. OTHERWISE, GUSTS  
OUTSIDE OF CONVECTION WILL REACH 20 KT, EXCEPT FOR THE  
CHARLESTON COUNTY NEARSHORE WATERS WHERE SOME 25 KT GUSTS WILL  
OCCUR. AN ONGOING SMALL CRAFT ADVISORY CONTINUES FOR THE  
CHARLESTON COUNTY NEARSHORE WATERS INTO TONIGHT. WIND GUSTS IN  
THE CHARLESTON HARBOR WILL BE MARGINAL, SO WE WILL CONTINUE TO  
MONITOR TO SEE IF A SCA IS WARRANTED. SEAS WILL PEAK NO MORE  
THAN 4-5 FEET.  
 
SATURDAY WILL SEE BREEZY WEST-NORTHWESTERLY WINDS THROUGHOUT THE  
MORNING HOURS, TURNING SOUTHWESTERLY DURING THE AFTERNOON, WITH  
STRONGEST WINDS EXPECTED ALONG THE SOUTH CAROLINA NEARSHORE WATERS  
AT UP TO 20 KNOTS. WHILE WE CURRENTLY DO NOT HAVE THE WINDS REACHING  
SMALL CRAFT ADVISORY CRITERIA ON SATURDAY, MARINERS SHOULD CHECK  
BACK BEFORE HEADING OUT AS THE FORECAST MAY FAVOR STRONGER WINDS.  
WAVE HEIGHTS OF 2 TO 4 FEET ARE EXPECTED. WINDS WEAKEN OVERNIGHT  
INTO SUNDAY AS THEY BECOME WESTERLY.  
 
THE WINDS ON SUNDAY WILL REMAIN WEAK, BECOMING SOUTHWESTERLY AND  
THEN SOUTHERLY THROUGHOUT THE AFTERNOON HOURS. WAVES OF 1 TO 2 FEET  
EXPECTED. THERE IS A LOW END CHANCE FOR SCATTERED THUNDERSTORMS  
SUNDAY AFTERNOON AND EVENING, WHICH MAY BE CAPABLE OF PRODUCING  
BREEZY WINDS.  
 
MONDAY INTO WEDNESDAY: OUTSIDE OF POTENTIAL SHOWERS AND THUNDERSTORM  
ACTIVITY ON MONDAY AFTERNOON/EVENING, NO MARINE CONCERNS AT THIS  
TIME.  
 

 
   
CHS WATCHES/WARNINGS/ADVISORIES
 
 
GA...NONE.  
SC...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 3 AM EDT SATURDAY FOR AMZ350.  
 

 
 

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