384
FXUS62 KCHS 271118
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
718 AM EDT FRI MAR 27 2026
WHAT HAS CHANGED
ALL KEY MESSAGES AND SECTIONS HAVE BEEN UPDATED.
KEY MESSAGES
- 1) NEAR RECORD WARMTH TODAY.
- 2) HAZARDOUS CONDITIONS ARE LIKELY ON LAKE MOULTRIE LATE TONIGHT
INTO SATURDAY.
- 3) FIRE WEATHER WATCHES ARE IN EFFECT FOR SOUTHEAST SC AND
MOST OF SOUTHEAST GA ON SATURDAY.
- 4) DRY WITH ABOVE NORMAL TEMPERATURES NEXT WEEK.
DISCUSSION
KEY MESSAGE 1: NEAR RECORD WARMTH TODAY.
THE CENTER OF A 588 DM RIDGE WILL REMAIN OVER THE TX/MEXICO, WITH
THE H5 RIDGE EXTENDING EAST ACROSS THE SOUTHEAST U.S. AT THE SFC, A
STRONG BACKDOOR COLD FRONT IS FORECAST TO STRETCH ACROSS THE MID-
ATLANTIC STATES SOUTHWEST TO THE SOUTHERN APPALACHIANS BY 18Z. IN
ADDITION, A DEEPENING FRONTAL WAVE IS EXPECTED TO DEVELOP OVER THE
FOOTHILLS NEAR THE NC/VA LINE THIS AFTERNOON. THIS PATTERN WILL
SUPPORT WSW SFC WINDS ACROSS THE FORECAST AREA TODAY. THE RETURN
FLOW SHOULD RESULT IN H85 TEMPS TO WARM TO AROUND 15C THIS
AFTERNOON. HIGH RESOLUTION GUIDANCE INDICATES THAT A SEA BREEZE WILL
ADVANCE INLAND THIS AFTERNOON. GIVEN NEARLY FULL INSOLATION, MILD
LLVL THICKNESS, AND AFTERNOON SEA BREEZE, HIGH TEMPERATURES SHOULD
FAVOR VALUES IN THE UPPER 80S. THESE TEMPERATURES WOULD CHALLENGE
RECORD HIGHS FOR TODAY, SEE CLIMATE SECTION.
KEY MESSAGE 2: HAZARDOUS CONDITIONS ARE LIKELY ON LAKE MOULTRIE LATE
TONIGHT INTO SATURDAY.
WINDS WILL INCREASE ON LAKE MOULTRIE LATE TONIGHT INTO SATURDAY
BEHIND A STRONG SOUTHWARD MOVING COLD FRONT. CONDITIONS COULD GET
HAZARDOUS ON THE OPEN LAKE WATERS WITH WINDS REACHING AS HIGH AS 20-
25 KT WITH GUSTS UP TO 30 KT. WAVE ACTION COULD BE SIGNIFICANT WITH
WAVES REACHING 2-3 FT AT TIMES, ESPECIALLY OVER THE CENTRAL AND
SOUTHERN PORTIONS OF THE LAKE. A LAKE WIND ADVISORY IS IN EFFECT
FROM MIDNIGHT TONIGHT UNTIL EARLY SATURDAY AFTERNOON.
KEY MESSAGE 3: FIRE WEATHER WATCHES ARE IN EFFECT FOR SOUTHEAST SC
AND MOST OF SOUTHEAST GA ON SATURDAY.
A DRY COLD FRONT WILL BE FAR OFFSHORE AT DAYBREAK SATURDAY.
MEANWHILE, HIGH PRESSURE WILL BE BUILDING IN FROM THE NORTHWEST.
THE CENTER OF THIS HIGH WILL PASS FAR TO OUR NORTH LATE SATURDAY.
THE HIGH WILL USHER SIGNIFICANTLY DRIER AIR AND BREEZY WINDS INTO
OUR AREA, CREATING DANGEROUS FIRE WEATHER CONDITIONS.
AS IS TYPICAL FOR THIS TYPE OF SPRING PATTERN, MODELS ARE FAILING TO
ADEQUATELY CAPTURE JUST HOW DRY IT WILL BE. THEREFORE, WE WENT MUCH
DRIER THAN GUIDANCE, GOING WITH THE NBM10 FOR DEW POINTS, WHICH
ARGUABLY MIGHT NOT BE DRY ENOUGH. BUT IT MATCHES UP WITH MINIMUM RH
VALUES IN THE HREF. DEW POINTS WILL DROP INTO THE UPPER TEENS AND
20S ACROSS MOST INLAND AREAS, BUT REMAIN HIGHER AT/NEAR THE BEACHES.
THIS WILL CAUSE AFTERNOON RH VALUES TO DROP INTO THE MID/UPPER TEENS
VERY FAR INLAND, WHILE GENERALLY BEING IN THE LOW/MID 20S ACROSS
MOST OF OUR AREA, WITH HIGHER VALUES AT/NEAR THE BEACHES. THESE
VALUES WILL BE REACHED LATE IN THE AFTERNOON.
ADDITIONALLY, COLD AIR ADVECTION AND PRESSURE RISES FROM THE HIGH
WILL LEAD TO GUSTY NORTHERLY, THEN NORTHEASTERLY WINDS. THE
STRONGEST GUSTS WILL BE IN THE MORNING, PEAKING IN THE 25-35 MPH
RANGE ACROSS OUR SC COUNTIES AND THE 20-30 MPH RANGE ACROSS OUR GA
COUNTIES. WINDS SHOULD GRADUALLY EASE INTO THE AFTERNOON, WHICH IS
WHEN RH VALUES WILL REALLY DROP. SO THE STRONGEST WINDS AND LOWEST
RH VALUES WON'T LINE UP PERFECTLY.
HOWEVER, STATE, MILITARY, AND FEDERAL LAND MANAGEMENT AGENCIES HAVE
REPORTED SOME EXTREME FIRE BEHAVIOR WITH CONTROLLED BURNS AND A FEW
WILDFIRES OVER THE PAST FEW DAYS. THIS IS ON TOP OF THE ONGOING
DROUGHT.
PER COORDINATION WITH NEIGHBORING NWS OFFICES AS WELL AS VARIOUS
FIRE WEATHER PARTNERS, A FIRE WEATHER WATCH HAS BEEN ISSUED FOR ALL
OF OUR SC COUNTIES, AND MOST OF OUR GA COUNTIES. THE START TIME IS 8
AM, WHICH IS PROBABLY TOO EARLY FOR OUR AREA. BUT IT WAS DONE TO
ASSIST STATE MESSAGING. THE END TIME WAS INITIALLY GOING TO BE 11
PM, AGAIN FOR STATE MESSAGING. BUT THIS WAS HARD TO JUSTIFY WITH
WINDS SIGNIFICANTLY EASING AROUND SUNSET AND RH VALUES REALLY RISING
CLOSER TO THE COAST. SO THE COMPROMISED END TIME WAS ADJUSTED TO 8
PM, WHICH IS HISTORICALLY WHEN CONDITIONS IMPROVE ACROSS OUR AREA.
AN UPGRADE TO A RED FLAG WARNING WOULD BE WITH THIS AFTERNOONS
FORECAST PACKAGE.
KEY MESSAGE 4: DRY WITH ABOVE NORMAL TEMPERATURES NEXT WEEK.
MID-LEVEL RIDGING WILL PREVAIL OVER THE SOUTHEAST U.S. MOST OF NEXT
WEEK WHILE SURFACE HIGH PRESSURE IS IN THE WESTERN ATLANTIC. THIS
PATTERN WILL CONTINUE TO BRING DRY CONDITIONS TO OUR AREA. HIGH
TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL ON SUNDAY, THEN RISE
ABOVE NORMAL ON MONDAY. THE WARMING TREND CONTINUES TUESDAY THROUGH
THURSDAY.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
VFR IS EXPECTED TO PREVAIL THROUGH THE 12Z TAF PERIOD. MOS AND
FORECAST SOUNDINGS INDICATES THAT SOUTHWEST WINDS WILL DEVELOP
GUSTS AT KCHS AND KJZI THIS AFTERNOON WITH A SEA BREEZE, BOTH
TAFS WILL FEATURE GUSTS BETWEEN 15 TO 20 KTS. KSAV MAY SEE
OCCASIONAL GUSTS BETWEEN 17-20Z, HIGHLIGHTED WITH A TEMPO. WIND
GUSTS SHOULD END AROUND SUNSET. A STRONG COLD FRONT IS TIMED TO
PUSH ACROSS KCHS AND KJZI BY 8Z AND KSAV BY 10Z. GUSTS SHOULD
INCREASE TO 25 TO 30 KTS BY THE END OF THE 12Z TAFS.
EXTENDED AVIATION OUTLOOK: VFR. THERE WILL BE GUSTY WINDS BEHIND A
DRY COLD FRONT ON SATURDAY.
MARINE
ROUNDS OF SEA FOG MAY LIFT NORTH ACROSS THE NEARSHORE WATERS THIS
MORNING, GRADUALLY DISSIPATING THIS AFTERNOON. THE COASTAL WATERS
WILL REMAIN UNDER A BROAD PRESSURE GRADIENT TODAY THROUGH THIS
EVENING. THIS PATTERN SHOULD SUPPORT SOUTHWEST WINDS BETWEEN 10 TO
15 KTS WITH GUSTS NEAR 20 KTS. SEAS ARE FORECAST TO BUILD TO AROUND
3 FT THIS AFTERNOON/EVENING.
EXTENDED MARINE: A DRY COLD FRONT WILL BE WELL OFFSHORE BY DAYBREAK
SATURDAY. HIGH PRESSURE WILL THEN START BUILDING IN FROM THE
NORTHWEST EARLY SATURDAY, THEN SHIFT OFF THE MID- ATLANTIC COAST
INTO SUNDAY. THIS WILL BRING GALE CONDITIONS TO ALL OF OUR WATERS
EARLY SATURDAY, FOLLOWED BY NEAR GALE CONDITIONS LATER SATURDAY INTO
EARLY SUNDAY. WE HAVE GALE WATCHES IN EFFECT TO ACCOUNT FOR THIS.
CONDITIONS WILL FURTHER IMPROVE ON MONDAY. THOUGH, SEAS COULD STAY
ELEVATED ACROSS THE GA WATERS BEYOND 20 NM INTO MONDAY NIGHT.
HIGH SURF: BREAKING WAVE HEIGHTS COULD REACH 5-6 FT ALONG PARTS OF
THE GEORGIA COAST SUNDAY. A HIGH SURF ADVISORY MAY BE NEEDED.
CLIMATE
RECORD HIGH TEMPERATURES:
MARCH 27:
KCHS: 87/2021
KCXM: 81/2021
KSAV: 89/2021
CHS WATCHES/WARNINGS/ADVISORIES
GA...FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY
EVENING FOR GAZ087-088-099>101-114>119-137-138.
SC...FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY
EVENING FOR SCZ040-042>045-047>052.
LAKE WIND ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EDT SATURDAY
FOR SCZ045.
MARINE...GALE WATCH FROM SATURDAY MORNING THROUGH SATURDAY AFTERNOON
FOR AMZ330.
GALE WATCH FROM SATURDAY MORNING THROUGH SATURDAY AFTERNOON
FOR AMZ350-352-354.
GALE WATCH FROM SATURDAY MORNING THROUGH LATE SATURDAY NIGHT
FOR AMZ374.
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