175
FXUS62 KCHS 230729
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
229 AM EST MON FEB 23 2026
WHAT HAS CHANGED
MINOR CHANGES MADE TO KEY MESSAGE 1 IN REGARDS TO ONGOING COLD
WEATHER THIS MORNING AND RETURN TONIGHT. ADDED KEY MESSAGE 2 TO
REFLECT HAZARDOUS CONDITIONS ACROSS LAKE MOULTRIE. ADDED KEY MESSAGE
3 TO REFLECT BREEZY WINDS AND LOW RH SUPPORTIVE OF A FIRE DANGER
STATEMENT TODAY. UPDATED THE AVIATION SECTION FOR THE 06Z TAF
ISSUANCE. UPDATED TO MARINE SECTION TO REFLECT ONGOING GALE WARNINGS
AND SMALL CRAFT ADVISORIES TODAY INTO TONIGHT.
KEY MESSAGES
- 1) COLD WEATHER WITH SUB-FREEZING TEMPERATURES CONTINUES EARLY THIS
MORNING WITH ANOTHER ROUND TO RETURN TONIGHT.
- 2) GUSTY WINDS EXPECTED TO PRODUCE HAZARDOUS CONDITIONS ACROSS LAKE
MOULTRIE THIS MORNING.
- 3) BREEZY WINDS WITH LOW RELATIVE HUMIDITY VALUES ENHANCES
FIRE WEATHER CONCERNS LATE MORNING THROUGH THE EVENING.
DISCUSSION
KEY MESSAGE 1: COLD WEATHER WITH SUB-FREEZING TEMPERATURES CONTINUES
EARLY THIS MORNING WITH ANOTHER ROUND TO RETURN TONIGHT.
A MODIFIED ARCTIC AIRMASS WILL CONTINUE TO FILTER INTO THE REGION
THIS MORNING AS SPRAWLING HIGH PRESSURE BUILDS SOUTHWARD FROM SOUTH-
CENTRAL CANADA. THIS WILL YIELD WELL BELOW-FREEZING TEMPERATURES
THIS MORNING AND TOMORROW MORNING AS WIND CHILLS DROP INTO THE UPPER
TEENS TO LOW 20S SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA.
NAEFS ESAT MINIMUM TEMPERATURE ANAMOLIES HINT AT THESE BELOW-AVERAGE
TEMPERATURES WELL WITH VALUES RANGING FROM -3 TO -5 FOR THIS MORNING
THROUGH TOMORROW MORNING.
TEMPERATURES BEGAN TO FALL THIS PREVIOUS AFTERNOON AS BREEZY WEST-
NORTHWESTERLY WINDS SOARED THROUGH THE REGION, AND WILL CONTINUE TO
DROP INTO THE LOW TO MID 20S INLAND AND UPPER 20S TO LOW 30S ALONG
THE COASTLINE. THESE BREEZY WINDS WILL MAKE IT FEEL LIKE LOW TO MID
20S AREA-WIDE, WITH UPPER-TEENS INLAND. HENCE, A COLD WEATHER
ADVISORY HAS BEEN ISSUED UNTIL 8AM THIS MORNING FOR ALL OF THE SOUTH
CAROLINA LOWCOUNTRY AND SOUTHEAST GEORGIA. IT'S IMPORTANT TO NOTE
THAT IT WILL BE MARGINAL FOR THE COASTAL ZONES AS WIND CHILL VALUES
BOTTOM OUT NEAR 20F, BUT AN ADVISORY SEEMED WARRANTED CONSIDERING
THE NEAR RECORD TO RECORD WARMTH THAT HAS BEEN EXPERIENCED RECENTLY.
HIGH TEMPERATURES WILL STRUGGLE TO REACH 50F (MORE THAN 15 DEGREES
BELOW NORMAL FOR FEB.) TODAY AS THIS ARCTIC AIRMASS CONTINUES TO
FILTER INTO THE REGION. ALSO, LINGERING NORTHWESTERLY WINDS WILL
MAKE IT FEEL CLOSER TO THE UPPER 30S TO LOW 40S, WHICH IS A BIG
CHANGE COMPARED TO THE LAST COUPLE DAYS. THE COLDEST PERIOD IS
EXPECTED TONIGHT INTO TOMORROW MORNING, WITH LOWS IN THE LOW 20S
INLAND AND MID TO UPPER 20S NEAR THE COASTLINE. SIMILAR TO THIS
MORNING, WIND CHILL VALUES WILL FALL INTO THE LOW TO MID 20S, WITH A
FEW UPPER TEENS POSSIBLE ACROSS THE INLAND COUNTIES. ADDITIONALLY,
THE 01Z.NBM MINIMUM TEMPS. FORECAST FOR TOMORROW MORNING INDICATE A
IQR RANGE OF 1-2 DEGREES, REFLECTING A TIGHTLY CLUSTERED
DISTRIBUTION AND REINFORCING A HIGH DEGREE OF CONFIDENCE IN THE
FORECAST. HENCE, A COLD WEATHER ADVISORY WILL LIKELY BE WARRANTED
ACROSS THE INLAND COUNTIES FOR TONIGHT INTO TOMORROW MORNING,
HOWEVER IT WILL BE MARGINAL FOR THE COASTAL ZONES AS WIND VALUES
BOTTOM NEAR 20F AGAIN. THE NEED FOR AN ADVISORY WILL BE REASSESSED
AGAIN TODAY. HIGHS ON TUESDAY WILL MODERATE SLIGHTLY, REACHING INTO
THE LOW TO MID 50S.
KEY MESSAGE 2: GUSTY WINDS EXPECTED TO PRODUCE HAZARDOUS CONDITIONS
ACROSS LAKE MOULTRIE THIS MORNING.
COLD HIGH PRESSURE CONTINUES TO SPREAD ACROSS THE REGION EARLY THIS
MORNING WITH GUSTY NORTHWEST WINDS IN THE 20-25 KT COMMON ACROSS AND
NEARBY LAKE MOULTRIE. WATER TEMPS IN THE MID 50S WILL CONTINUE TO
PROMOTE LOW-LVL MIXING SUPPORTIVE OF GUSTS AROUND 25 KT INTO MID
MORNING HOURS TODAY, RESULTING IN A LAKE WIND ADVISORY UNTIL 9 AM.
SOME GUIDANCE SUGGESTS GUSTY WINDS CONTINUING INTO AFTERNOON HOURS
PRIOR TO THE PRESSURE GRADIENT WEAKENING LATE DAY. SHOULD TRENDS AND
SFC OBS SUPPORT HIGHER GUSTS, THE LAKE WIND ADVISORY COULD NEED TO
BE EXTENDED INTO MID-LATE AFTERNOON HOURS TODAY.
KEY MESSAGE 3: BREEZY WINDS WITH LOW RELATIVE HUMIDITY VALUES
ENHANCES FIRE WEATHER CONCERNS LATE MORNING THROUGH THE EVENING.
SUSTAINED NORTHWESTERLY WINDS OF 15 TO 20 MPH WITH GUSTS UP TO 25-30
MPH ARE EXPECTED LATE THIS MORNING THROUGH THE EVENING AS A LOW
PRESSURE SYSTEM SHIFTS FARTHER AWAY AND SURFACE HIGH PRESSURE BUILDS
INTO THE REGION. THIS DOWNSLOPE FLOW REGIME WILL CONTINUE TO USHER
IN A DRIER AIRMASS AND YIELD RELATIVE HUMIDITY VALUES BETWEEN 25-30%
THIS AFTERNOON. DESPITE THE MEASURABLE PRECIPITATION THIS PAST
WEEKEND, THESE CONDITIONS WILL SUPPORT ELEVATED FIRE WEATHER
CONCERNS TODAY. THEREFORE, A FIRE DANGER STATEMENT HAS BEEN ISSUED
FROM 11AM UNTIL 7PM (AFTER SUNSET).
AVIATION /07Z MONDAY THROUGH FRIDAY/
VFR CONDITIONS WILL PREVAIL AT CHS/JZI/SAV TERMINALS THROUGH 06Z
TUESDAY. HOWEVER, GUSTY NORTHWEST/WEST WINDS (AROUND 20-25 KT) WILL
CONTINUE AT THE TERMINALS EARLY MORNING AND AFTERNOON, BEFORE
WEAKENING EARLY EVENING.
EXTENDED AVIATION OUTLOOK: AN APPROACHING FRONT COULD BRING
FLIGHT RESTRICTIONS LATE THURSDAY INTO FRIDAY.
MARINE
TODAY AND TONIGHT: COLD HIGH PRESSURE WILL CONTINUE TO SPREAD ACROSS
COASTAL WATERS, WITH SUFFICIENT LOW-LVL MIXING INTO 35-40 KT 1000MB
GEOSTROPHIC WINDS SUPPORTING FREQUENT GUSTS TO GALE FORCE ACROSS
NEARSHORE SC/GA WATERS AND OFFSHORE GA WATERS. A GALE WARNING
REMAINS IN EFFECT UNTIL 9 AM AS A RESULT, BEFORE WINDS SLOWLY
DECREASE LATE MORNING THROUGH THE AFTERNOON. A PERIOD OF SMALL CRAFT
ADVISORIES WILL FOLLOW GALE WARNINGS AS WELL, AND COULD PERSIST
THROUGH MUCH OF TONIGHT WITH WINDS STILL GUSTING TO AROUND 25 KT
ACROSS NEARSHORE AND OFFSHORE WATERS. SEAS WILL SUBSIDE WITH A
CONTINUED OFFSHORE FLOW PRESENT, EVENTUALLY REACHING THE 2-4 FT
RANGE ACROSS NEARSHORE WATERS BY SUNSET WHILE HOLDING IN THE 4-6 FT
RANGE ACROSS OFFSHORE GA WATERS FOR MUCH OF THE NIGHT.
IN THE CHARLESTON HARBOR, A SMALL CRAFT ADVISORY WILL REMAIN IN
EFFECT UNTIL EARLY AFTERNOON, ALTHOUGH COULD NEED TO BE EXTENDED
INTO LATE EVENING SHOULD GUSTY WINDS PERSIST AROUND THE HARBOR INTO
MID-LATE AFTERNOON HOURS.
TUESDAY THROUGH FRIDAY: HIGH PRESSURE WILL PREVAIL ACROSS LOCAL
WATERS THROUGH MID-WEEK WITH NO MARINE CONCERNS EXPECTED. HOWEVER,
WINDS AND SEAS SHOULD INCREASE/BUILD WITH THE APPROACH OF A COLD
FRONT EARLY WEEKEND, WHICH COULD SUPPORT SMALL CRAFT ADVISORIES
ACROSS A MAJORITY OF LOCAL WATERS THURSDAY AND FRIDAY. HIGH PRESSURE
SHOULD THEN RETURN DURING THE WEEKEND.
CHS WATCHES/WARNINGS/ADVISORIES
GA...COLD WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR GAZ087-
088-099>101-114>119-137>141.
SC...COLD WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ040-
042>045-047>052.
LAKE WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ330.
GALE WARNING UNTIL 9 AM EST THIS MORNING FOR AMZ350-352-354-
374.
DENNIS/DPB
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