889  
FXUS62 KCHS 051955  
AFDCHS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON SC  
355 PM EDT SAT JUL 5 2025  
   
SYNOPSIS  
 
TROPICAL STORM CHANTAL IS FORECAST TO APPROACH THE SOUTH  
CAROLINA COAST TONIGHT AND MOVE ONSHORE SUNDAY MORNING. HIGH  
PRESSURE WILL REBUILD INTO THE AREA NEXT WEEK.  
 
 
   
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/  
 
TROPICAL STORM CHANTAL LOCATED OFF THE SC COAST CONTINUES TO SLOWLY  
MOVE NORTH, APPROACHING THE SC COAST. THE LATEST SPC MESOANALYSIS  
INDICATES THAT PW VALUES RANGED FROM 2.3 INCHES ALONG THE COAST TO  
AROUND 2 INCHES INLAND. SBCAPE VALUES REMAINED LIMITED BY THE CLOUD  
COVER AND FREQUENT SHOWERS, VALUES RANGED BETWEEN 500-1000 J/KG,  
WITH VERY LITTLE NORMALIZED CAPE. GIVEN THE FZL NEAR 16 KFT AND  
MARGINAL INSTABILITY, THE MENTION OF THUNDERSTORMS WILL BE LIMITED  
TO A SCHC. USING THE 12 HREF GUIDANCE, POPS WILL GRADUALLY INCREASE  
THROUGH THIS EVENING AND TONIGHT, ESPECIALLY ACROSS THE CHS TRI-  
COUNTY. HIGH RESOLUTION GUIDANCE INDICATES THAT RAIN BANDS WILL  
BECOME LARGER AND GAPS BETWEEN THE BANDS DECREASES. HREF INDICATES  
THAT VALUES OF 1"/3HRS WILL PEAK BETWEEN 50-70 PERCENT BETWEEN  
CHARLESTON AND THE SOUTH SANTEE RIVER AROUND 6Z. IN ADDITION, VALUES  
OF 3"/3HR ACROSS THE SAME AREA WILL PEAK AROUND 10 PERCENT. THROUGH  
TONIGHT, RAINFALL TOTALS ARE FORECAST TO RANGE BETWEEN 1 TO 3 INCHES  
ACROSS THE CHS TRI-COUNTY, WITH THE GREATEST VALUES ACROSS BERKELEY  
AND CHARLESTON COUNTIES NEAR THE SANTEE RIVER.  
 
THE PRESSURE GRADIENT BETWEEN CHANTAL AND HIGH PRESSURE RIDGED  
ACROSS THE WESTERN CAROLINAS WILL PEAK THIS AFTERNOON, THEN MAY  
GRADUALLY DECREASE INTO THE OVERNIGHT HOURS. THE PINCHED GRADIENT  
COMBINED WITH MIXING TO 2-3 KFT HAS YIELD GUSTY CONDITIONS ACROSS  
THE REGION, ESPECIALLY ALONG THE SC COAST AND ADJACENT ATLANTIC  
WATERS. A LAKE WIND ADVISORY WILL REMAIN IN EFFECT UNTIL 8 PM. NHC  
TRACK AND WIND FORECAST FOR CHANTAL INDICATES THAT A BAND OF STRONG  
WINDS AROUND THE SYSTEM'S CENTER WILL APPROACH THE NORTHERN  
CHARLESTON COUNTY COAST LATE TONIGHT, BRINGING ANOTHER ROUND OF  
STRONGER WINDS CLOSER TO THE TRACK LINE. PLEASE SEE NHC'S LATEST  
ADVISORY.  
 
 
   
SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/  
 
SUNDAY: THE LATEST NHC FORECAST HAS TROPICAL STORM CHANTAL MAKING  
LANDFALL BY SUNDAY 12Z/8AM EDT NEAR THE MOUTH OF THE SOUTH SANTEE  
RIVER, WEAKENING TO A TROPICAL DEPRESSION AS IT MOVES ACROSS  
SOUTHWESTERN SOUTH CAROLINA. THIS WILL CONTINUE CHANCES FOR  
SCATTERED SHOWERS SHOWERS, EXPANDING SOUTHWARDS INTO SOUTHEAST  
GEORGIA THROUGHOUT THE MORNING AS THE TD CONTINUES TO WEAKEN. WHILE  
THE THREAT HAS DECREASED SLIGHTLY NOW THAT WE'RE DEPENDENT ON WRAP  
AROUND MOISTURE MAKING IT AROUND THE SURFACE LOW, PRECIPITABLE WATER  
VALUES OF 2-2.5 INCHES COMBINED WITH REPEATED/TRAINING STORMS WILL  
CONTINUE THE THREAT OF LOCALLY HEAVY RAINFALL. OTHERWISE, ASIDE FROM  
AREAS IN NORTHERN CHARLESTON COUNTY WHERE WINDS WILL BE A TOUCH  
STRONGER DUE TO PROXIMITY TO THE WEAKENING TS, EXPECT WINDS TO SWING  
AROUND FROM WEST-NORTHWESTERLY TO SOUTH-SOUTHWESTERLY THROUGHOUT THE  
DAY, WITH GUSTS INTO THE TEENS. HIGHS IN THE MID 80S TO LOWER 90S  
ARE EXPECTED, WITH PARTLY TO MOSTLY CLOUDY SKIES THROUGHOUT THE DAY.  
 
MONDAY AND TUESDAY: AS WEAK RIDGING OCCURS ALOFT, THE REMNANTS OF  
CHANTAL WILL CONTINUE TO LOSE INFLUENCE OVER THE AREA. IN ADDITION  
TO THE EXPECTED DAILY SEA-BREEZE, SOME WEAK SHORTWAVES PROPAGATING  
THROUGH THE SOUTHWESTERLY FLOW IN THE LOWER-LEVELS WILL KEEP CHANCES  
FOR LOW POPS IN THE AFTERNOON HOURS. WHILE SHEAR REMAINS WEAK AND  
THERE IS A LACK OF STRONG FORCING, CHANCES FOR SEVERE WEATHER REMAIN  
LOW, THOUGH GIVEN 1000-2000 J/KG OF CAPE THE CHANCES ARE NON-ZERO.  
MAX TEMPERATURES FOR MONDAY ARE IN THE MID 90S, RISING INTO THE MID  
TO UPPER 90S ON TUESDAY, WITH HEAT INDEX VALUES GETTING CLOSER TO  
THE HEAT ADVISORY CRITERIA OF 108 DEG F.  
 
 
   
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/  
 
WEAK FLOW WITHIN SUBTLE RIDGING ALOFT WILL PERSIST ALONG WITH NO  
DISCERNIBLE SYNOPTIC FEATURES. THE FORECAST WILL BE DOMINATED BY A  
TYPICAL SUMMERTIME SEA BREEZE PATTERN, WITH SCATTERED SHOWERS AND  
THUNDERSTORMS POSSIBLE EACH DAY ESPECIALLY IN THE AFTERNOON AND  
EARLY EVENING WHEN INSTABILITY IS MAXIMIZED. HIGHS ARE FORECAST TO  
CREEP BACK UP TO THE MID 90S INLAND OF THE COAST, WITH HEAT INDICES  
IN THE LOWER TO MID 100S.  
 
 
   
AVIATION /20Z SATURDAY THROUGH THURSDAY/  
 
05/18Z TAF DISCUSSION:  
IN THE NORTHWEST QUADRANT OF TS CHANTAL, NORTH-NORTHEAST WINDS  
ARE SUSTAINED IN THE LOWER TEENS TO LOWER 20 KNOTS RANGE, WITH  
GUSTS OF 20 TO 30 KNOTS. RADAR IS SHOWING SCATTERED RAIN BANDS  
MOVING IN FROM THE NORTHEAST, AND MVFR CIGS ACROSS PORTIONS OF  
SOUTHEASTERN SOUTH CAROLINA IMPROVING INTO VFR RANGE ACROSS  
SOUTHEASTERN GEORGIA. AS CHANTAL CONTINUES TO SLOWLY DRIFT  
NORTHEASTWARDS TOWARDS THE SOUTH SANTEE RIVER BY DAYBREAK  
SUNDAY, EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO  
CONTINUE TO REMAIN POSSIBLE, WITH WINDS REMAINING FAIRLY CONSISTENT  
FOR THE REST OF THE DAY. WINDS DECREASE OVERNIGHT AS THE  
INVERSION ATTEMPTS TO SET UP, THOUGH GUSTS INTO THE TEENS WILL  
LIKELY CONTINUE INTO THE MORNING HOURS. MVFR CIGS WILL ATTEMPT  
TO SPREAD OUT ACROSS THE REGION THIS EVENING, ESPECIALLY ACROSS  
SOUTHEASTERN SOUTH CAROLINA WHERE IFR CIGS WILL ALSO BE  
POSSIBLE, WITH COVERAGE UNCERTAIN FOR SOUTHEAST GEORGIA.  
 
EXTENDED AVIATION OUTLOOK: BRIEF CEILING/VSBY RESTRICTIONS POSSIBLE  
SUNDAY THROUGH WEDNESDAY DUE TO SCATTERED SHOWERS AND  
THUNDERSTORMS.  
 
 
   
MARINE  
 
TONIGHT, THE PRESSURE GRADIENT BETWEEN CHANTAL AND HIGH PRESSURE  
RIDGED ACROSS THE WESTERN CAROLINAS WILL PEAK THIS AFTERNOON, THEN  
MAY GRADUALLY DECREASE INTO THE OVERNIGHT HOURS. NHC TRACK AND WIND  
FORECAST FOR CHANTAL INDICATES THAT A BAND OF STRONG WINDS AROUND  
THE SYSTEM'S CENTER WILL APPROACH THE NORTHERN CHARLESTON COUNTY  
COAST LATE TONIGHT, BRINGING ANOTHER ROUND OF STRONGER WINDS CLOSER  
TO THE TRACK LINE. PLEASE SEE NHC'S LATEST ADVISORY.  
 
TROPICAL STORM WARNINGS ARE IN EFFECT FOR THE SC NEARSHORE WATERS  
WITH A TROPICAL STORM WATCH ACROSS THE CHS HARBOR. SC NEARSHORE  
WATERS SHOULD SEE NE WINDS 25-30 KT WITH GUSTS 40 KTS THROUGH LATE  
TONIGHT. AS CHANTAL TRACKS OVER THE NORTHERN CHARLESTON COUNTY  
NEARSHORE WATERS, WINDS AROUND THE CENTER MAY STRENGTHEN WITH GUSTS  
AROUND 45 KTS. AS A RESULT OF THE STRONG WINDS, SEAS WILL BUILD  
THROUGH THE NEAR TERM, REACHING 8-10 FT ACROSS THE CHARLESTON  
NEARSHORE WATERS AFTER MIDNIGHT. ELSEWHERE, CONDITIONS WILL REMAIN  
WITH SOLID SMALL CRAFT ADVISORY CONDITIONS, FEATURING GUSTS AROUND  
30 KTS AND SEAS 6 TO 7 FT. WAVE HEIGHTS WITHIN THE CHS HARBOR  
BETWEEN 1 TO 3 FT.  
 
SUNDAY THROUGH THURSDAY: CONDITIONS WILL DRASTICALLY IMPROVE ON  
SUNDAY AS THE FLOW BRIEFLY BECOMES OFFSHORE WITH THE TROPICAL SYSTEM  
LOCATED TO THE NORTH. WINDS WILL THEN SETTLE INTO A SW FLOW BY  
MONDAY AS HIGH PRESSURE REBUILDS. SEAS WILL REMAIN ELEVATED ACROSS  
THE CHARLESTON COUNTY NEARSHORE WATERS SUNDAY BEFORE LOWERING TO 3-4  
FT BY MONDAY. ELSEWHERE, SEAS 3-4 FT WILL DECREASE TO 2-3 FT BY  
MONDAY NIGHT. NO MARINE CONCERNS/HEADLINES EXPECTED BEYOND SUNDAY.  
 
RIP CURRENTS: A HIGH RISK FOR RIP CURRENTS REMAINS IN PLACE FOR ALL  
BEACHES THROUGH 8 PM THIS EVENING DUE TO A COMBINATION OF  
STRONG WINDS, BUILDING SWELL AND ONGOING RIP CURRENT REPORTS  
FROM THE VARIOUS LIFE GUARD GROUPS. A MODERATE RISK FOR RIP  
CURRENTS EXISTS FOR ALL AREA BEACHES ON SUNDAY DUE TO RESIDUAL  
SWELL, DECREASING BACK TO LOW RISK ON MONDAY.  
 
HIGH SURF: BUILDING NORTHEAST WINDS WILL PUSH SEAS OFF THE  
CHARLESTON COUNTY COAST TO 5-8 FT WITH LOCAL NWPS OUTPUT SHOWING  
BREAKING WAVES OF 4-6 FT OCCURRING BY THIS AFTERNOON AND CONTINUING  
THROUGH THE NIGHT ALONG PARTS OF THE CHARLESTON COUNTY BEACHES. THE  
BEACHES OF MOST CONCERN ARE KIAWAH ISLAND, FOLLY BEACH, SULLIVANS  
ISLAND AND DEWEES ISLAND. A HIGH SURF ADVISORY HAS BEEN POSTED FROM  
2 PM TODAY UNTIL 8 AM SUNDAY.  
 
 
   
TIDES/COASTAL FLOODING  
 
FOR THE 5 PM HIGH TIDE IN CHARLESTON, BASED TO TRENDS IN TIDAL  
DEPARTURES, WE WILL LOWER THE FORECAST TO AROUND 6.8 FT MLLW.  
THERE ARE NO CONCERNS FOR COASTAL FLOODING ALONG THE REMAINDER  
OF THE GEORGIA OR LOWER SOUTH CAROLINA COAST.  
 
 
   
CHS WATCHES/WARNINGS/ADVISORIES  
 
GA...HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR GAZ117-  
119-139-141.  
SC...TROPICAL STORM WATCH FOR SCZ050.  
HIGH RISK FOR RIP CURRENTS UNTIL 8 PM EDT THIS EVENING FOR  
SCZ048>051.  
LAKE WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SCZ045.  
HIGH SURF ADVISORY UNTIL 8 AM EDT SUNDAY FOR SCZ050.  
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR AMZ330.  
TROPICAL STORM WATCH FOR AMZ330.  
TROPICAL STORM WARNING FOR AMZ350-352.  
SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR AMZ354-374.  
 
 
 
 
 
NEAR TERM...NED  
SHORT TERM...APT  
LONG TERM...APT  
AVIATION...APT  
MARINE...APT/NED  
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