162
FXUS62 KCHS 201140
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
640 AM EST FRI FEB 20 2026
WHAT HAS CHANGED
THE AVIATION SECTION UPDATED FOR THE 12Z TAFS. MARINE DENSE FOG
ADVISORIES POSSIBLE FOR ALL COASTAL WATERS TODAY. LAKE WIND
ADVISORY ISSUED UNTIL 4 PM THIS AFTERNOON.
KEY MESSAGES
- 1) NEAR RECORD HIGH TEMPERATURES TODAY. ADDITIONALLY, GUSTY
SOUTHWEST WINDS WILL BE HIGHLIGHTED WITH A LAKE WIND ADVISORY.
- 2) STRONG TO SEVERE STORMS POSSIBLE ON SATURDAY AFTERNOON AND
EVENING.
- 3) SUB-FREEZING TEMPERATURES RETURN ON SUNDAY NIGHT AND
PERSIST INTO THE MID-WEEK.
DISCUSSION
KEY MESSAGE 1: NEAR RECORD HIGH TEMPERATURES TODAY. ADDITIONALLY,
GUSTY SOUTHWEST WINDS WILL BE HIGHLIGHTED WITH A LAKE WIND ADVISORY.
TODAY, GUSTY SOUTHWEST WINDS WILL ADVECT VERY MILD LLVL THICKNESSES
ACROSS THE FORECAST AREA TODAY. THE DAY SHOULD BEGIN WITH
TEMPERATURES IN THE LOW TO MID 60S. AFTER SUNRISE, TEMPERATURES
SHOULD STEADILY WARM THROUGH EARLY THIS AFTERNOON. TEMPERATURES ARE
FORECAST TO PEAK IN THE LOW 80S ACROSS INLAND GA WITH VALUES AROUND
80 DEGREES ACROSS MOST OF THE SC LOWCOUNTRY. THE FORECAST HIGH
TEMPERATURES ARE EXPECTED TO REMAIN WITHIN 3 DEGREES OF RECORD
VALUES, PRIMARILY AT KCHS AND KSAV (SEE CLIMATE SECTION). AS MIXING
HEIGHTS DEEPEN TO AROUND 3 KFT, WIND GUSTS MAY STRENGTHEN TO 25 TO
30 MPH.
RECENT RUNS OF THE HRRR AND HREF, INDICATE THAT A BAND OF SCATTERED
TO NUMEROUS SHOWERS WILL OUTPACE THE COLD FRONT, REACHING THE
FORECAST AREA THIS AFTERNOON. COVERAGE OF THE SHOWERS SHOULD REMAIN
THE GREATEST INLAND, ESPECIALLY OVER THE SAVANNAH RIVER. THESE
SHOWERS WILL BE SUPPORTED BY CAPE BETWEEN 300-800 J/KG AND 35 KTS OF
0-1KM BULK SHEAR.
LAKE WIND: SOUTHWEST WINDS WILL STRENGTHEN TO 15 TO 20 KTS WITH
GUSTS 25 KTS TODAY. A LAKE WIND ADVISORY HAS BEEN ISSUED FOR LAKE
MOULTRIE UNTIL 4 PM THIS AFTERNOON.
SEA FOG COULD ADVECT ONSHORE AND IMPACT THE BEACHES AND NEARBY
COASTAL LOCATIONS, WITH VISIBILITIES DROPPING TO 1 MILE OR LESS AT
TIMES TODAY. WE WILL MONITOR THE NEED FOR DENSE FOG ADVISORIES OVER
LAND.
KEY MESSAGE 2: STRONG TO SEVERE STORMS POSSIBLE ON SATURDAY
AFTERNOON AND EVENING.
A STALLED FRONT WILL LINGER ACROSS PARTS OF THE SOUTHEAST ON
SATURDAY AS A SHORTWAVE TROUGH APPROACHES THE REGION. AIDED BY
ADDITIONAL TROUGHING LOCATED OVER THE CENTRAL AND NORTHERN PLAINS,
THE MEAN-LVL FLOW ALOFT WILL STRENGTHEN AND BECOME INCREASINGLY
PARALLEL BY MID-DAY SATURDAY. SIMULTANEOUSLY, THIS WILL ENHANCE
CYCLOGENESIS ALONG THE STALLED FRONT IN THE NORTH-CENTRAL GULF AND
THEN TRANSLATE ACROSS SOUTH CAROLINA BY THE AFTERNOON. AS THIS
CYCLOGENESIS DEVELOPS, THIS STATIONARY FRONT WILL BE PUSHED
NORTHWARD THROUGHOUT THE EVENING AND WILL ALLOW FOR THE REGION TO BE
POSITIONED IN THE WARM SECTOR. EXPECT LOW-LVL MOISTURE TO INCREASE
AS DEWPOINTS CLIMB INTO THE MID TO UPPER 60S BY MID-DAY AS THE
SHORTWAVE TROUGH INCHES CLOSER. ADDITIONALLY, 0-6KM BULK SHEAR ON
THE ORDER OF 50 TO 70 KT WILL BE PREVALENT BY LATE SATURDAY
AFTERNOON. THE 20/01Z NBM DEPICTS A RISK FOR SBCAPE VALUES >500 J/KG
BY LATE SAT. AFTERNOON (~4-5PM) WITH THE GREATEST POTENTIAL ACROSS
PORTIONS OF SOUTHEAST GEORGIA. THESE FACTORS WILL SUPPORT A MODESTLY
UNSTABLE ENVIRONMENT AND YIELD SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS, WITH THE PRIMARY WINDOW FOR SEVERE THUNDERSTORMS IN
THE EARLY AFTERNOON THROUGH THE EVENING. THE MAIN HAZARD WILL BE
DAMAGING STRAIGHT-LINE WINDS WITH GUSTS POTENTIALLY REACHING 60 MPH
WITHIN THE STRONGER THUNDERSTORMS. HOWEVER, A BRIEF WEAK TORNADO
REMAINS A NON-ZERO CHANCE (MAINLY ACROSS SOUTHEAST GEORGIA) AS
MODEST LOW-LVL HELICITY AND 0-6KM BULK SHEAR WILL BE PRESENT. TO
REFLECT THIS SEVERITY, SPC HAS HIGHLIGHTED THE REGION IN MARGINAL
RISK FOR SEVERE THUNDERSTORMS ON SATURDAY. THE MAIN UNCERTAINTY WILL
BE CENTERED AROUND HOW MUCH INSTABILITY CAN DEVELOP IN THE WARM
SECTOR, AS THIS WILL DETERMINE IF THE SEVERE RISK WILL NEED TO BE
HEIGHTENED.
ALONG WITH THE SEVERE WEATHER RISK, EXPECT RAINFALL VALUES FROM 0.40
TO 1.0 INCHES FROM SAT. MORNING THROUGH SUN. MORNING AS THE
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS (MAINLY INDUCED BY
ISENTROPIC ASCENT AND WARM-AIR ADVECTION) PUSH ACROSS THE REGION.
VERTICAL CROSS SECTIONS SHOW MODEST DEEP-LAYERED UVVS INDUCED BY
DPVA AHEAD OF A SHORTWAVE THAT IS FORECAST TO DIG ACROSS THE
TENNESSEE VALLEY INTO THE SOUTHERN APPALACHIANS. 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 3: SUB-FREEZING TEMPERATURES RETURN ON SUNDAY NIGHT AND
PERSIST INTO THE MID-WEEK.
AS A COLD FRONT SLIDES OFF THE COASTLINE ON SUNDAY MORNING, EXPECT
COLD SURFACE HIGH PRESSURE TO BUILD IN BEHIND AND ALLOW THE RETURN
OF WINTER-LIKE TEMPERATURES ON MONDAY AND TUESDAY MORNING. SOME
UNCERTAINTY STILL EXISTS WITH THIS SYSTEM AS THE 00Z.LREF CLUSTER-1
ANALYSIS CONTAINS ROUGHLY 45% OF THE GEPS MEMBERS AND 35% OF THE
ENSEMBLE MEMBERS, EMPHASIZING THE SPLIT OF SOLUTIONS. HOWEVER, THE
NAEFS ESAT SEEMS TO BE SUPPORTIVE OF BELOW-NORMAL TEMPERATURES AS IT
DEPICTS TEMPERATURE ANAMOLIES RANGING FROM -2 TO -4 ON MONDAY AND
TUESDAY MORNING. THE FORECAST REFLECTS THESE BELOW-AVERAGE
TEMPERATURES WITH MINIMUM TEMPERATURES ON MONDAY MORNING RANGING
FROM UPPER 20S TO LOW 30S AND LOW TO MID 20S ON TUESDAY MORNING.
THESE TEMPERATURES COMBINED WITH BREEZY WINDS WILL AID IN WIND CHILL
VALUES IN THE LOW TO MID 20S EACH MORNING. THE CHANCE FOR WIND
CHILLS TO DROP BELOW 20 DEGREES (COLD WEATHER ADVISORY CRITERIA) HAS
LESSENED AND SEEMS LESS LIKELY WITH THE 20/01Z NBM. BOTH MONDAY AND
TUESDAY, EXPECT HIGHS TO RECOVER TO ONLY THE UPPER 40S TO LOW 50S AS
THE COOLER AIRMASS STICKS AROUND. AFTERWARDS, EXPECT TEMPERATURES TO
WARM BACK UP ON WEDNESDAY THROUGH THE END OF THE WEEK.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
12Z TAFS: PRIOR TO THE 12Z, KCLX VAD WIND PROFILE OBSERVED 40
KTS AT 2 KFT. WIND SFC WINDS LESS THAN 10 KTS, LLWS IS EXPECTED
UNTIL 13Z OVER KCHS. ALL TERMINALS WILL DEVELOP GUSTS INTO THE
LOW 20 KTS BY 13Z, WHICH WILL END THE LLWS AT KCHS. BY 17Z,
MIXING MAY DEEPEN TO AROUND 3 KFT ACROSS THE TERMINALS,
RESULTING IN GUSTS AROUND 25 KTS. HIGH RESOLUTION GUIDANCE
INDICATES THAT BAND OF SCATTERED PRE-FRONTAL SHOWERS MAY PASS
OVER THE TERMINALS BETWEEN 18-22Z, HIGHLIGHTED WITH A TEMPO OR
PROB30 AT EACH TERMINAL. WIND GUSTS SHOULD END BY 22Z, WIND
WINDS REMAINING FROM THE SOUTHWEST THROUGH THE REST OF THE 6Z
TAF PERIOD.
EXTENDED AVIATION OUTLOOK: FLIGHT RESTRICTIONS ARE LIKELY AT TIMES
THROUGH THE WEEKEND DUE TO POTENTIAL ADVECTION OF MARINE STRATUS
INLAND AS WELL AS SCATTERED SHOWERS/THUNDERSTORMS FRIDAY AND
SATURDAY.
MARINE
SEA FOG: EARLY THIS MORNING, IR SATELLITE SHOWED A LARGE AREA OF LOW
CLOUDS ACROSS GA/FL, SLIDING TO THE EAST. WITH CLOUD BASES BELOW 1
KFT, ONCE THE LOW CLOUDS DRIFT OVER THE COOLER SHELF WATERS, STRATUS
BUILD-DOWN SHOULD RAPIDLY EXPAND SEA FOG ACROSS THE COASTAL WATERS.
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FROM THE PRE-DAWN HOURS
THIS MORNING INTO THIS AFTERNOON.
THE PRESSURE GRADIENT PINCHES TODAY, WIND GUSTS ACROSS A PORTION OF
THE SC WATERS MAY GUSTS TO AROUND 25 KTS DURING THE DAYLIGHT HOURS.
SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR CHARLESTON COUNTY
NEARSHORE, CHS HARBOR, AND OUTER GA WATERS. A FRONTAL WAVE IS
FORECAST TO DEVELOP OVER THE I-20 CORRIDOR OF THE DEEP SOUTH
TONIGHT, TRACKING EAST ON SATURDAY. THE ASSOCIATED COLD FRONT IS
TIMED TO PUSH OVER THE MARINE ZONES SATURDAY EVENING, WITH CAA AND
STRENGTHENING WINDS SATURDAY NIGHT. ON SUNDAY, SMALL CRAFT ADVISORY
CONDITIONS SHOULD SPREAD ACROSS THE NEARSHORE SC/GA WATERS WITH
GALES POSSIBLE ACROSS THE OUTER GA WATERS. GUSTY WINDS AND ELEVATED
SEAS MAY LINGER INTO MONDAY.
CLIMATE
RECORD HIGH TEMPERATURES:
FEBRUARY 20:
KCHS: 82/2018
KSAV: 84/1991
FEBRUARY 21:
KSAV: 84/2018
RECORD HIGH MINIMUM TEMPERATURES:
FEBRUARY 20:
KSAV: 64/1939
FEBRUARY 21:
KCHS: 62/2023
KSAV: 63/2023
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ330-
350.
DENSE FOG ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR AMZ350.
SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR AMZ374.
DENNIS/NED
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page