413
FXUS62 KCHS 211806
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
106 PM EST SAT FEB 21 2026
WHAT HAS CHANGED
THE KEY MESSAGES, MARINE, AND AVIATION SECTIONS HAVE ALL BEEN
UPDATED. THE GALE WATCHES HAVE BEEN UPGRADED TO WARNINGS.
KEY MESSAGES
- 1) STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON AND
EVENING.
- 2) SUB-FREEZING TEMPERATURES RETURN SUNDAY NIGHT AND PERSIST
INTO THE MID-WEEK.
DISCUSSION
KEY MESSAGE 1: STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON
AND EVENING.
A STALLED FRONT CONTINUES TO LINGER ACROSS THE REGION WHILE AN UPPER
LEVEL SHORTWAVE DEEPENS ACROSS THE MISSISSIPPI VALLEY. LATEST RADAR
IMAGERY ALREADY SHOWS ONGOING SHOWERS TO OUR NORTH AND PORTIONS OF
OUR INLAND COUNTIES. WHILE THESE SHOWERS REMAIN LARGELY ELEVATED,
EXPECT A DEVELOPING SFC LOW TO NUDGE THE AFOREMENTIONED FRONT
NORTHWARD, RESULTING IN MORE SFC BASED SHOWERS AS THE REGION BECOMES
WARM-SECTORED. DESPITE HAVING A DECENT BIT OF CLOUD COVER, THINK
THERE WILL BE ENOUGH WAA IN PLACE TO HELP DESTABILIZE THE ATMOSPHERE
AND PROMOTE A FEW STRONG TO SEVERE THUNDERSTORMS.
IN TERMS OF DYNAMICS, LATEST SOUNDINGS SUGGEST SBCAPE VALUES BETWEEN
500-1000 J/KG, WITH SOME ISOLATED AREAS APPROACHING 1,500 J/KG. WITH
PWATS NEAR 1.5 INCHES AND DEWPOINTS IN THE MID 60S TO LOWER 70S,
CERTAINLY THINK WE HAVE ENOUGH MOISTURE TO WORK WITH. 0-6 KM BULK
SHEAR VALUES ALSO REMAIN DECENT, WITH VALUES GREATER THAN 50 KT. SO,
IN REGARD TO SEVERE WEATHER, SPC'S LATEST DAY 1 OUTLOOK DOES
MAINTAIN A MARGINAL RISK (LEVEL 1 OF 5) FOR OUR AREA. AS NOTED IN
THE PREVIOUS DISCUSSION, BELIEVE THE GREATEST RISK FOR SEVERE
WEATHER WILL REMAIN FOCUSED ACROSS SOUTHEASTERN GEORGIA (ALONG/SOUTH
OF I-16) AND POSSIBLY AS FAR NORTH AS BEAUFORT AND HARDEEVILLE IN
SOUTHERN SOUTH CAROLINA BETWEEN 3 AND 9 PM. DAMAGING WIND GUSTS IN
EXCESS OF 58 MPH AND FREQUENT LIGHTNING LOOK TO REMAIN THE PRIMARY
HAZARDS, THOUGH AN ISOLATED TORNADO OR TWO CANNOT BE RULED OUT.
IN ADDITION TO SEVERE WEATHER, WILL SEE RAINFALL TOTALS RANGE
BETWEEN 0.50 TO 1.25 INCHES THIS AFTERNOON THROUGH SUNDAY MORNING.
WHILE MOST SHOWERS SHOULD REMAIN MODERATE IN INTENSITY, DO WANT TO
EMPHASIZE THAT POCKETS OF HEAVIER RAIN MAY STILL OCCUR - WHICH COULD
EASILY SUPPORT SOME SPOTS RECEIVING UPWARDS OF 0.5 INCH OVER A 6
HOUR PERIOD. THIS COULD LEAD TO BRIEF URBAN, OR POOR DRAINAGE
FLOODING, PARTICULARLY IN THE CHARLESTON AND SAVANNAH METRO AREAS.
OTHERWISE, EXPECT COVERAGE AND INTENSITY TO GRADUALLY WANE THROUGH
THE OVERNIGHT PERIOD AS THE FRONT PUSHES EASTWARD TOWARD THE
ATLANTIC. OUTSIDE OF A FEW LINGERING SHOWERS ALONG THE COAST SUNDAY
MORNING, SHOULD SEE LARGELY DRY CONDITIONS RETURN ACROSS THE REGION
BY SUNDAY AFTERNOON.
KEY MESSAGE 2: SUB-FREEZING TEMPERATURES RETURN SUNDAY NIGHT
AND PERSIST INTO THE MID-WEEK.
AS A COLD FRONT PUSHES OFF THE COASTLINE ON SUNDAY MORNING, EXPECT
COLD SURFACE HIGH PRESSURE TO BUILD INTO THE REGION BEHIND IT. THIS
WILL YIELD A CONSIDERABLY COLDER AIRMASS FOR THE EARLY NEXT WEEK
WITH WELL BELOW-NORMAL TEMPERATURES, WIDESPREAD BELOW FREEZING
TEMPERATURES MONDAY AND TUESDAY MORNINGS, AND WIND CHILLS DROPPING
INTO THE UPPER TEENS TO LOW 20S FOR SOME AREAS.
TEMPERATURES WILL FALL SUNDAY AFTERNOON WITH BREEZY NORTHWEST WINDS
AND CONTINUED COLD AIR ADVECTION THROUGH SUNDAY NIGHT. BY MONDAY
MORNING, LOWS WILL REACH THE UPPER 20S INLAND AND LOW 30S ALONG THE
COASTLINE, BUT GUSTY WINDS WILL MAKE IT FEEL LIKE LOW TO MID 20S
AREA-WIDE, WITH UPPER TEENS POSSIBLE INLAND. THEREFORE, A COLD
WEATHER ADVISORY MIGHT BE WARRANTED. HIGHS ON MONDAY WILL STRUGGLE
TO REACH 50F (MORE THAN 15 DEGREES BELOW NORMAL FOR FEB.).
THE COLDEST PERIOD IS EXPECTED MONDAY NIGHT INTO TUESDAY MORNING,
WITH LOWS IN THE LOW TO MID 20S INLAND AND UPPER 20S NEAR THE
COASTLINE. DESPITE WIND SPEEDS BEING MUCH LIGHTER, WIND CHILLS WILL
STILL FALL INTO THE LOW TO MID 20S, WITH A FEW UPPER TEENS POSSIBLE.
ANOTHER COLD WEATHER ADVISORY MAY BE WARRANTED. HIGHS ON TUESDAY
WILL MODERATE SLIGHTLY, REACHING INTO THE LOW TO MID 50S.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
18Z TAFS: SHOWERS AND THUNDERSTORMS, PERHAPS A FEW SEVERE, ARE
EXPECTED TO BLOSSOM ACROSS THE REGION THIS AFTERNOON, CAUSING CIGS
AND VSBYS TO LOWER TO MVFR TO IFR LEVELS. COULD EVEN SEE SOME BRIEF
PERIODS OF LIFR OCCUR UNDER HEAVIER DOWNPOURS. OTHERWISE, EXPECT
THESE FLIGHT LEVELS TO BECOME MORE WIDESPREAD AND PERSISTENT AFTER
SUNSET. PRECIPITATION COVERAGE AND INTENSITY THEN GRADUALLY WANE
FROM WEST TO EAST OVERNIGHT, WITH DRY CONDITIONS AND VFR LEVELS
EXPECTED TO RETURN BY LATE TOMORROW MORNING. WINDS BECOME
NORTHWESTERLY AND QUITE BREEZY IN THE WAKE OF THE FRONT, WITH GUSTS
BETWEEN 20-30 KT POSSIBLE BY THE END OF THE PERIOD.
EXTENDED AVIATION OUTLOOK: VFR.
MARINE
THROUGH THIS EVENING: A STRONGER BAND OF
SHOWERS/THUNDERSTORMS WILL MOVE THROUGH THE WATERS. THESE STORMS
COULD PRODUCE LOCALIZED WIND GUSTS IN EXCESS OF 34 KT, ISOLATED
WATERSPOUTS, AND CLOUD-TO-WATER LIGHTNING. SPECIAL MARINE
WARNINGS COULD EVENTUALLY BE NEEDED.
LOW PRESSURE WILL MOVE NORTHEAST OF OUR AREA TONIGHT, DRAGGING A
STRONG COLD FRONT WITH IT. THIS FRONT SHOULD MOVE THROUGH OUR WATERS
EARLY SUNDAY MORNING, THEN QUICKLY SHIFT OFFSHORE, CAUSING WINDS TO
SHIFT TO THE NORTHWEST. STRONG HIGH PRESSURE WILL THEN START
BUILDING IN FROM THE WEST. THE INTERACTION BETWEEN THESE TWO
SYNOPTIC FEATURES ALONG WITH STRONG COLD AIR ADVECTION WILL BRING
GALE CONDITIONS TO THE WATERS SUNDAY AFTERNOON INTO SUNDAY NIGHT.
THEREFORE, WE UPGRADED THE GALE WATCHES TO GALE WARNINGS. NORMALLY,
WE WOULD HAVE SMALL CRAFT ADVISORIES IN EFFECT BEFORE THE WARNINGS.
HOWEVER, THE WINDS RAMP UP SO RAPIDLY THAT THE ADVISORIES WOULD ONLY
BE IN EFFECT FOR 2-3 HOURS. THEREFORE, WE JUST OPTED TO START THE
WARNINGS A LITTLE EARLIER. WE ALSO HAVE A SMALL CRAFT ADVISORY FOR
THE CHARLESTON HARBOR. CONDITIONS IMPROVE ON MONDAY, AS HIGH
PRESSURE GETS CLOSER TO THE REGION. WINDS AND SEAS WILL BE
NOTICEABLY LOWER ON TUESDAY AS THE HIGH MOVES OVER OUR REGION.
CLIMATE
RECORD HIGH TEMPERATURES:
FEBRUARY 21:
KSAV: 84/2018
RECORD HIGH MINIMUM TEMPERATURES:
FEBRUARY 21:
KCHS: 62/2023
KSAV: 63/2023
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 3 PM SUNDAY TO 8 AM EST MONDAY FOR
AMZ330.
GALE WARNING FROM 3 PM SUNDAY TO 8 AM EST MONDAY FOR AMZ350.
GALE WARNING FROM 1 PM SUNDAY TO 8 AM EST MONDAY FOR AMZ352-
354.
GALE WARNING FROM 11 AM SUNDAY TO 8 AM EST MONDAY FOR AMZ374.
SST/DPB
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