506
FXUS62 KCHS 312244
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
644 PM EDT MON MAR 31 2025
SYNOPSIS
SHOWERS AND THUNDERSTORM WILL OCCUR THIS EVENING AHEAD OF A
COLD FRONT. THE FRONT LINGERS NEARBY MID-WEEK, BEFORE STRONGER
HIGH PRESSURE PREVAILS LATE THIS WEEK. ANOTHER COLD FRONT COULD
APPROACH LATER THIS WEEKEND.
NEAR TERM /UNTIL 6 AM TUESDAY MORNING/
EARLY EVENING: ALOFT, H5 SHORTWAVE ENERGY WILL QUICKLY MOVE
INTO GEORGIA BY MID-AFTERNOON, REACHING SOUTHERN SOUTH CAROLINA
BY EARLY EVENING. AT THE SFC, A STRONG COLD FRONT WILL CROSS THE
APPALACHIAN MOUNTAINS, APPROACHING THE REGION DURING THE
EVENING AND OVERNIGHT, KEEPING THE LOCAL AREA SOLIDLY WITHIN A
MOIST WARM-SECTOR THROUGH EARLY EVENING HOURS.
LATEST RADAR TRENDS INDICATE A LINE OF THUNDERSTORMS QUICKLY
MAKING WAY TO COASTAL COMMUNITIES EARLY THIS EVENING, LIKELY
SHIFTING OFFSHORE DURING THE NEXT HOUR. INSTABILITY HAS
DECREASED SUBSTANTIALLY DURING THE LAST HOUR AND THE BULK OF
CONVECTION IS OUT-RUNNING STRONGER SHEAR/LOW-LVL WIND FIELDS.
HOWEVER, THUNDERSTORMS WILL REMAIN CAPABLE OF PRODUCING DAMAGING
WIND GUSTS WHILE SHIFTING OFFSHORE. A SEVERE THUNDERSTORM WATCH
REMAINS IN EFFECT UNTIL 9 PM FOR AREAS EAST OF I-95 AS A
RESULT. STRATIFORM RAINS FOLLOWING THE INITIAL LINE WILL
CONTINUE FOR AN ADDITIONAL 1-2 HOURS, BEFORE ACTIVITY ENDS FOR
MOST AREAS THE REMAINDER OF THE NIGHT.
ADDITIONAL RAINFALL EAST OF I-95 UPWARDS TO 1/3 TO 2/3 INCHES IS
LIKELY, WITH LOCALIZED AMOUNTS AROUND 1 INCH OVER A SHORT PERIOD
OF TIME DURING THUNDERSTORMS. FORTUNATELY THE HIGH TIDE OCCURS A
FEW HOURS AFTER THE SQUALL LINE PASSES OFFSHORE.
LATE EVENING AND OVERNIGHT: THE TRAILING COLD FRONT IS NOT EXPECTED
TO REACH THE LOCAL AREA UNTIL LATE NIGHT, ALLOWING A FEW ADDITIONAL
SHOWERS TO PERSIST ACROSS THE LOCAL AREA UNTIL FROPA OCCURS.
SKIES SHOULD ALSO BEGIN TO CLEAR OUT LATE AND WITH RECENT RAINS/WET
GROUNDS, PATCHY FOG REMAINS A POSSIBILITY UNTIL AROUND DAYBREAK.
LOW TEMPS SHOULD GENERALLY RANGE IN THE MID 50S INLAND TO LOWER
60S CLOSER TO THE COAST.
SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/
AS A COLD FRONT DEPARTS OFFSHORE, CANADIAN HIGH PRESSURE SPREADING
SOUTH INTO THE MIDWEST WILL GRADUALLY FILTER INTO THE SOUTHEAST
TUESDAY. SURFACE HIGH PRESSURE WILL THEN CONTINUE TO BUILD ACROSS
THE FORECAST AREA THROUGH THE PERIOD AS THE CENTER SHIFTS OVER THE
NEW ENGLAND REGION AND EVENTUALLY OVER THE CENTRAL ATLANTIC.
SIMULTANEOUSLY, AN UPPER RIDGE WILL SET UP EAST OF THE FLORIDA
PENINSULA ALLOWING FOR WARMING TEMPERATURES EACH DAY. SKIES WILL
BECOME MOSTLY CLEAR TUESDAY AFTERNOON BEHIND THE FROPA WITH SOME
ADDITIONAL CLOUDS DEVELOPING FOR WEDNESDAY AND THURSDAY. VERY WEAK
SIGNALS OF SHORTWAVE ACTIVITY ALOFT COMBINED WITH MOISTURE PRESENT
WEDNESDAY COULD RESULT IN AN ISOLATED SHOWER OR THUNDERSTORM, MAINLY
FOR INLAND COUNTIES. OTHERWISE, THE FORECAST WILL BE RAIN-FREE
THROUGH THE PERIOD.
THE HIGHLIGHT OF THE FORECAST THIS WEEK WILL BE THE ABOVE NORMAL,
POSSIBLY RECORD-BREAKING TEMPERATURES (SEE CLIMATE SECTION BELOW).
NO REAL SEMBLANCE OF ANY COLD AIR ADVECTION IN THE WAKE OF THE FRONT
WILL QUICKLY SHIFT TO WAA AS FLOW SHIFTS OUT OF THE SOUTH TUESDAY
NIGHT. ALSO, TRENDS SHOW A CONTINUED PATTERN OF HIGHER THAN "NORMAL"
GEOPOTENTIAL HEIGHTS AS WE NEAR THE LATTER HALF OF THE WEEK. HIGHS
WILL REACH THE UPPER 70S TO LOW 80S ACROSS SOUTHEAST SOUTH CAROLINA
AND LOW TO MID 80S ACROSS SOUTHEAST GEORGIA TUESDAY AND A COUPLE OF
DEGREES WARMER FORECAST FOR WEDNESDAY. BY THURSDAY, MID TO UPPER 80S
ARE FORECAST EVERYWHERE WITHIN THE FORECAST AREA WITH THE EXCEPTION
OF THE IMMEDIATE COAST WHERE UPPER 70S ARE EXPECTED. IT IS POSSIBLE
SOME LOCATIONS, ESPECIALLY ACROSS INTERIOR SOUTHEAST GEORGIA, COULD
HIT THE 90 DEGREE MARK. ONSHORE FLOW WILL HELP PROMOTE A PROGRESSIVE
SEA BREEZE EACH DAY WHICH WILL AID IN COOLING AT LEAST THE COASTAL
COMMUNITIES PRIOR TO SUNSET. LOWS IN THE UPPER 50S TUESDAY NIGHT
WILL JUMP TO THE MID 60S FOR WEDNESDAY NIGHT.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
THE LONG TERM CONTINUES TO REMAIN LARGELY WARM AND DRY AS A STRONG
UPPER LEVEL RIDGE REMAINS IN PLACE JUST OFF TO OUR SOUTH. HIGHS IN
THE MID TO UPPER 80S WILL BE COMMON THROUGH THE WEEKEND, WITH
ISOLATED LOCATIONS PEAKING IN THE LOWER 90S. A STRONG UPPER LEVEL
WAVE MOVING OUT OF THE ONTARIO PROVIDENCE SUNDAY INTO MONDAY
ACCOMPANIED BY A SURFACE HIGH PRESSURE MOVING INTO THE CENTRAL
PLAINS WILL SEND A COLD FRONT TOWARDS THE REGION LATER THIS WEEKEND
INTO EARLY NEXT WEEK. SCATTERED SHOWERS ARE EXPECTED PRIOR TO THE
FRONTAL PASSAGE, WITH COOLER TEMPERATURES FORECAST FOR MONDAY IN THE
LOWER/MID 70S.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
TEMPO MVFR CIGS/VSBYS (AND PERHAPS LOWER) REMAIN IN THE
FORECAST UNTIL ROUGHLY 00-01Z THIS EVENING WITH A LINE OF
THUNDERSTORMS IMPACTING ALL TERMINALS. GUSTY WINDS UPWARDS TO
25-35 KT ARE ALSO POSSIBLE WITH THUNDERSTORMS. CIGS WILL LOWER
TO MINIMUM MVFR (AND POSSIBLY IFR) LEVELS AT ALL TERMINALS
BETWEEN 07-15Z TUESDAY, BEFORE IMPROVING BY AROUND DAYBREAK POST
FROPA, AND EVENTUALLY TO VFR BY MID-LATE MORNING TUESDAY.
EXTENDED AVIATION OUTLOOK: ASIDE FROM POSSIBLE LOW CEILINGS WITH ANY
ISOLATED SHOWER ACTIVITY ON WEDNESDAY, GENERALLY NO CONCERNS FOR
FLIGHT RESTRICTIONS THROUGH THE WEEK.
MARINE
TONIGHT: THE LOCAL AREA WILL REMAIN POSITIONED ALONG THE
WESTERN PERIPHERY OF HIGH PRESSURE CENTERED EAST OF BERMUDA
WHILE A STRONG COLD FRONT MOVES INTO THE SOUTHEAST THIS EVENING,
AND MOVES ACROSS THE LOCAL WATERS LATE NIGHT. SOUTH/SOUTHWEST
WINDS AROUND 10-15 KT WITH SOME GUSTS UP TO 20 KT ARE POSSIBLE
ACROSS THE CHARLESTON HARBOR AND NEARBY COASTAL WATERS. SEAS
WILL GENERALLY RANGE BETWEEN 3-5 FT, LARGEST NEAR 20 NM AND
FARTHER OFFSHORE ACROSS OUTER GEORGIA WATERS.
THE BIGGEST CONCERN FOR MARINERS WILL BE STRONG AND SEVERE T-STORMS
THAT OCCUR WITH A LINE OF THUNDERSTORMS PUSHING OFFSHORE EARLY THIS
EVENING, GENERALLY IMPACTING LOCAL WATERS AROUND 6-10 PM. DAMAGING
WIND GUSTS IN EXCESS OF 40 OR EVEN 50 KT CAN OCCUR, ALONG WITH
FREQUENT LIGHTNING STRIKES AND BRIEF VERY HEAVY RAINS THAT REDUCE
VISIBILITIES UNDER 1 NM AT TIMES. A SEVERE THUNDERSTORM WATCH IS
CURRENTLY IN PLACE FOR ALL NEARSHORE WATERS, INCLUDING THE
CHARLESTON HARBOR, AND SPECIAL MARINE WARNINGS WILL LIKELY BE NEEDED
DURING THIS TIME.
TUESDAY THROUGH SATURDAY: SURFACE HIGH PRESSURE WILL BUILD IN FROM
THE NORTH AS A COLD FRONT PUSHES OFFSHORE TUESDAY, WITH GENERALLY NO
MARINE CONCERNS EXPECTED THROUGH THE END OF THE WEEK. THERE IS A
SMALL CHANCE SOME PATCHY FOG OVER THE COASTAL NEARSHORE WATERS COULD
REMAIN/DEVELOP BEHIND ANY LINGERING SHOWERS EARLY TUESDAY MORNING.
CLIMATE
RECORD HIGH TEMPERATURES:
APRIL 4:
KSAV: 91/1963
APRIL 5:
KCHS: 89/1978
KSAV: 90/1988
APRIL 6:
KCHS: 90/1967
KSAV: 90/1967
RECORD HIGH MINIMUM TEMPERATURES:
MARCH 31:
KCXM: 68/1938
APRIL 2:
KCHS: 65/2012
APRIL 3:
KCHS: 67/2012
KCXM: 68/2012
KSAV: 68/2012
APRIL 4:
KCHS: 70/1974
KCXM: 69/1974
KSAV: 69/1974
APRIL 5:
KCHS: 65/2017
KCXM: 67/2023
KSAV: 66/1957
APRIL 6:
KSAV: 68/2023
EQUIPMENT
THE KCLX RADAR REMAINS OFFLINE FOR DOME MAINTENANCE THROUGH
APRIL 1, 2025. RADAR DATA WILL NOT BE AVAILABLE DURING THIS
TIME. USERS ARE URGED TO USE ADJACENT WSR-88D SITES WHICH ALSO
COVER MUCH OF SOUTHEAST SOUTH CAROLINA, SOUTHEAST GEORGIA AND
THE ADJACENT COASTAL WATERS. THESE INCLUDE:
KCAE - COLUMBIA, SC
KLTX - WILMINGTON, NC
KJAX - JACKSONVILLE, FL
KJGX - ROBBINS AFB, GA
KVAX - MOODY AFB, GA (MAY ALSO BE UNAVAILABLE DUE TO
MAINTENANCE)
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...DPB
SHORT TERM...BRS
LONG TERM...BRS
AVIATION...BRS/DPB
MARINE...BRS/DPB
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