344
FXUS62 KCHS 210700
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
200 AM EST SAT FEB 21 2026
WHAT HAS CHANGED
KEY MESSAGES HAVE BEEN UPDATED TO REFLECT SEVERE WEATHER POTENTIAL
THIS AFTERNOON/EVENING AND COLD TEMPERATURES EARLY NEXT WEEK. THE
AVIATION SECTION HAS BEEN UPDATED FOR THE 06Z TAF ISSUANCE. THE
MARINE SECTION HAS BEEN UPDATED TO REFLECT GALE WATCHES SUNDAY
AFTERNOON INTO MONDAY MORNING.
KEY MESSAGES
- 1) STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON AND EVENING.
- 2) SUB-FREEZING TEMPERATURES RETURN ON SUNDAY NIGHT AND PERSIST
INTO THE MID-WEEK.
DISCUSSION
KEY MESSAGE 1: STRONG TO SEVERE STORMS POSSIBLE THIS AFTERNOON
AND EVENING.
A STALLED FRONT WILL LINGER ACROSS PORTIONS OF SOUTH CAROLINA TODAY
AS A SHORTWAVE TROUGH LOCATED OVER THE MISSISSIPPI VALLEY DEEPENS
AND SHIFTS INTO THE REGION. SIMULTANEOUSLY, A SURFACE LOW WILL
DEVELOP ALONG THE STALLED FRONT IN THE NORTH-CENTRAL GULF AND THEN
TRANSLATE ACROSS SOUTH CAROLINA BY THE AFTERNOON. AS THE UPPER-LVL
TROUGH STRENGTHENS, THIS LOW IS EXPECTED TO DEEPEN WHILE TRACKING
EASTWARD AND EVENTUALLY OFFSHORE BY EARLY SUNDAY MORNING. INCREASING
LARGE-SCALE ASCENT AND LOW-LVL MOISTURE WILL SUPPORT SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEASTERN GEORGIA AND
SOUTHEASTERN SOUTH CAROLINA THROUGHOUT TODAY AND INTO TONIGHT, WITH
SOME POTENTIAL FOR DAMAGING WIND GUSTS AND A BRIEF WEAK TORNADO.
ELEVATED THUNDERSTORMS COULD BE ONGOING ALONG THE FRONT IN THE EARLY
MORNING AS MODEST HEATING TRIES TO DEVELOP SOUTH OF THIS FRONT. AS
THIS SURFACE LOW DEVELOPS, IT SHOULD PUSH THE FRONT NORTHWARDS
THROUGHOUT THE DAY AND MOST OF SOUTHEAST GEORGIA AND SOUTHEAST SOUTH
CAROLINA SHOULD BE SITUATED IN THE WARM SECTOR, HOWEVER SOME
UNCERTAINTY REMAINS ON HOW QUICKLY THIS FRONT LIFTS NORTHWARD.
THEREFORE, IF THE FRONT STRUGGLES TO QUICKLY LIFT NORTHWARD, THE
CHARLESTON TRI-COUNTY COULD WRESTLE TO PRODUCE ANY REASONABLE
INSTABILITY FOR THUNDERSTORM DEVELOPMENT. HOWEVER, MODERATE
INSTABILITY SHOULD BUILD THROUGHOUT THE DAY AS DEWPOINTS CLIMB INTO
THE MID TO UPPER 60S. EXPECT SBCAPE VALUES TO RANGE FROM 500 TO 1000
J/KG ACROSS THE REGION WITH SOME POCKETS ABOVE 1000 J/KG POSSIBLE
ACROSS SOUTHEAST GEORGIA (ESP. IN THE AFTERNOON HOURS). FORECAST
HODOGRAPHS DEPICT ELONGATED, RELATIVELY STRAIGHT PROFILES LARGELY
PARALLEL TO THE FRONT, YIELDING THE POTENTIAL FOR ORGANIZED LINE
SEGMENTS, OR CLUSTERS TO FORM. HOWEVER, A BRIEF WEAK TORNADO (MAINLY
IN SOUTHEAST GEORGIA) CANNOT BE RULED OUT NEAR THE BREAKS OF A QLCS
AND/OR BOWING LINE SEGMENTS AS 0-6KM BULK SHEAR ON THE ORDER OF 50
TO 70 KT WILL BE PRESENT. THE RISK FOR SEVERE WEATHER REMAINS
HIGHEST ACROSS SOUTHEAST GEORGIA BETWEEN 2PM TO 9PM, ROUGHLY
ALONG/SOUTH OF I-16 (AWAY FROM THE IMMEDIATE COASTLINE), AND
POSSIBLY AS FAR NORTH AS BEAUFORT AND HARDEEVILLE IN SOUTHERN SOUTH
CAROLINA. TO REFLECT THIS SEVERITY, SPC HAS HIGHLIGHTED THE REGION
IN MARGINAL RISK FOR SEVERE THUNDERSTORMS TODAY. THE MAIN
UNCERTAINTY WILL BE CENTERED AROUND HOW MUCH INSTABILITY CAN DEVELOP
IN THE WARM SECTOR, AS THIS WILL DETERMINE IF THE SEVERE WEATHER
RISK WILL NEED TO BE INCREASED.
ALONG WITH THE SEVERE WEATHER RISK, EXPECT RAINFALL VALUES FROM 0.50
TO 1.25 INCHES TODAY THROUGH SUN. MORNING AS THE SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS (MAINLY INDUCED BY ISENTROPIC
ASCENT AND WARM-AIR ADVECTION) PUSH ACROSS THE REGION. THIS COUPLED
PWATS CLIMBING ABOVE 1.5 INCHES AND THE PRESENCE OF SOME SURFACE-
BASED INSTABILITY SHOULD EASILY SUPPORT SOME SPOTS RECEIVING OVER AN
0.50 INCHES OVER A 6-HOUR PERIOD. THIS COULD LEAD TO BRIEF URBAN, OR
POOR DRAINAGE FLOODING, PARTICULARLY IN THE CHARLESTON AND SAVANNAH
METRO AREAS.
THESE SHOWERS AND THUNDERSTORMS SHOULD GRADUALLY SHIFT OFFSHORE BY
LATE SATURDAY EVENING AS THE FRONT CLEARS OFF THE COASTLINE,
FOLLOWED BY VEERING WINDS AND DRYING FROM WEST TO EAST OVERNIGHT.
EXPECT COOLER AND MORE STABLE AIR TO FILTER INTO THE REGION BY EARLY
SUNDAY MORNING AND EFFECTIVELY END THE SEVERE WEATHER THREAT.
KEY MESSAGE 2: SUB-FREEZING TEMPERATURES RETURN ON 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 /06Z SATURDAY THROUGH WEDNESDAY/
VFR CONDITIONS SHOULD PREVAIL FOR THE NEXT COUPLE HOURS AT
CHS/JZI/SAV TERMINALS THROUGH ABOUT 08-10Z SATURDAY, ALTHOUGH A LINE
OF SHOWERS COULD IMPACT CHS/JZI AND PRODUCE TEMPO MVFR CONDITIONS
PRIOR TO 08Z. EXPECT MVFR CONDITIONS TO DEVELOP AT CHS/JZI TERMINALS
PRIOR TO DAYBREAK, THEN CONTINUE TO DETERIORATE TO IFR AS LOW CLOUDS
AND SHOWER ACTIVITY OCCUR ALONG A FRONT NEARBY. IFR CONDITIONS
SHOULD THEN PREVAIL WITH CONTINUED LOW CLOUDS AND SHOWER ACTIVITY
PERSISTING THROUGH 06Z SUNDAY. THE RISK FOR A FEW THUNDERSTORMS WILL
ALSO INCREASE LATE AFTERNOON INTO EARLY EVENING. PROB30 GROUPS HAVE
BEEN INTRODUCED FOR THUNDERSTORMS AND LOWER VSBYS BETWEEN 02-06Z
SUNDAY.
AT SAV, THE RISK FOR MVFR AND EVEN IFR CIGS COMES SOONER (AROUND
08Z), BUT SHOULD REMAIN IN THE MVFR CATEGORY FOR A BULK OF THE TIME
LATER TONIGHT AND THROUGH EARLY AFTERNOON. VFR CONDITIONS
TEMPORARILY RETURN AT SAV DURING MID AFTERNOON PRIOR TO
SHOWER/THUNDERSTORM ACTIVITY RETURNING WITH A COLD FRONT APPROACHING
FROM THE WEST LATE IN THE TAF PERIOD. A PROB30 GROUP FOR
THUNDERSTORMS AND REDUCED VSBYS HAS ALSO BEEN ADDED AT SAV BETWEEN
02-06Z, ALTHOUGH THE RISK FOR THUNDERSTORMS SHOULD INCREASE LATE
AFTERNOON INTO EARLY EVENING.
EXTENDED AVIATION OUTLOOK: PERIODS OF FLIGHT RESTRICTIONS WILL BE
POSSIBLE THROUGH SUNDAY MORNING PRIMARILY DUE TO SHOWERS AND/OR LOW
CLOUDS ASSOCIATED WITH A COLD FRONT SHIFTING OFFSHORE. VFR
CONDITIONS SHOULD THEN PREVAIL AS HIGH PRESSURE BUILDS ACROSS THE
REGION NEXT WEEK.
MARINE
TODAY AND TONIGHT: SOUTH/SOUTHWEST WINDS SHOULD SETTLE INTO THE 10-
15 KT RANGE WITH SEAS BETWEEN 2-3 FT WHILE A FRONT BECOMES
POSITIONED NORTH AND INLAND TO THE AREA. THERE ARE NO WIND/SEAS
CONCERNS OUTSIDE CONVECTION AT THIS TIME. HOWEVER, A BAND OF
SHOWERS/TSTMS COULD PUSH OFF OF THE COAST LATE AFTERNOON AND EVENING
HOURS. 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.
SUNDAY THROUGH WEDNESDAY: A STRONG COLD FRONT WILL MOVE ACROSS THE
AREA SUNDAY MORNING, RESULTING IN INCREASINGLY HAZARDOUS MARINE
CONDITIONS ACROSS LOCAL WATERS AS STRONG COLD AIR ADVECTION POST
FRONT PROMOTES LOW-LVL MIXING INTO 40-45 KT 1000MB GEOSTROPHIC
WINDS. AS A RESULT, A GALE WATCH HAS BEEN ISSUED FOR ALL NEARSHORE
SC/GA WATERS AND OFFSHORE GEORGIA WATERS SUNDAY AFTERNOON THROUGH
MONDAY MORNING, WITH GUSTS UP TO 35-40 KT AT TIMES. THE CHARLESTON
HARBOR REMAINS OUT OF THE GALE WATCH FOR NOW, BUT SHOULD SEE SMALL
CRAFT ADVISORY LEVEL CONDITIONS FOR A PERIOD BEHIND THE FRONT AS
WELL. THERE COULD BE A 6-HR PERIOD OF SMALL CRAFT ADVISORIES LEADING
INTO THE CURRENT GALE WATCH SUNDAY MORNING/AFTERNOON, WHICH WILL
NEED TO BE FURTHER REFINED FOR A POSSIBLE ISSUANCE. MARINE
CONDITIONS WILL THEN GRADUALLY IMPROVE BACK BELOW SMALL CRAFT
ADVISORY THRESHOLDS MONDAY THROUGH MONDAY NIGHT AS HIGH PRESSURE
BUILDS ACROSS THE REGION THROUGH THE MIDDLE OF NEXT WEEK.
SEA FOG: SOME GUIDANCE SUGGESTS ANOTHER ROUND OF SEA FOG DEVELOPING
PRIOR TO DAYBREAK AND LINGERING THROUGH LATE MORNING, ALTHOUGH
INCREASING WINDS AND SHOWER ACTIVITY COULD LIMIT THIS ACTIVITY.
CONDITIONS WILL CONTINUE TO BE MONITORED FOR POSSIBLE MARINE DENSE
FOG ADVISORIES.
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...GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY MORNING FOR
AMZ350-352-354.
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON FOR
AMZ374.
DENNIS/DPB
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