395
FXUS62 KCHS 191808
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
108 PM EST THU FEB 19 2026
WHAT HAS CHANGED
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 18Z TAF ISSUANCE. KEY
MESSAGE 2 HAS BEEN INTRODUCED TO ADDRESS COLD WEATHER CONCERNS
NEXT WEEK. KEY MESSAGE 1 WAS UPDATED.
KEY MESSAGES
- 1) UNSETTLED AND WARM CONDITIONS WILL LINGER INTO THE WEEKEND
BRINGING ABOVE NORMAL WARMTH AND A RISK FOR SEVERAL
POTENTIALLY IMPACTFUL HAZARDS.
- 2) COLD WEATHER WILL RETURN SUNDAY NIGHT INTO TUESDAY NIGHT.
DISCUSSION
KEY MESSAGE 1: UNSETTLED AND WARM CONDITIONS WILL LINGER INTO
THE WEEKEND BRINGING ABOVE NORMAL WARMTH AND A RISK FOR SEVERAL
POTENTIALLY IMPACTFUL HAZARDS.
A FAIRLY ACTIVE PERIOD IS AHEAD. A COLD FRONT WILL APPROACH THE
SOUTHEAST U.S. FRIDAY AS OCCLUDED LOW PRESSURE WEAKENS OVER THE
GREAT LAKES REGION AND SECONDARY CYCLOGENESIS OCCURS OFF THE
MID- ATLANTIC COAST. THE FRONT WILL GRADUALLY SLOW AND STALL
ACROSS THE REGION SATURDAY AS IT BECOMES INCREASINGLY PARALLEL
WITH THE MEAN FLOW ALOFT. LOW PRESSURE IS FORECAST TO DEVELOP
ALONG THE NORTH- CENTRAL GULF COAST SATURDAY AFTERNOON, WHICH
WILL QUICKLY TRANSLATE ACROSS CENTRAL GEORGIA/THE SOUTH CAROLINA
MIDLANDS SATURDAY EVENING BEFORE EXITING OFF THE NORTH CAROLINA
CRYSTAL COAST EARLY SUNDAY MORNING. AS THE LOW APPROACHES
SATURDAY EVENING, THE STATIONARY FRONT WILL PUSH NORTH BRINGING
MUCH OF THE LOWCOUNTRY AND SOUTHEAST GEORGIA BACK INTO THE WARM
SECTOR BEFORE A COLD FRONT FINALLY SWEEPS OFFSHORE SATURDAY
NIGHT. COLD HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT THEN
PREVAIL THROUGH THE MIDDLE OF NEXT WEEK. THIS STORM SYSTEM WILL
BEING MUCH MUCH NEEDED RAINFALL TO THE AREA ALONG WITH A RISK
FOR SEVERAL IMPACTS/HAZARDS.
RAIN CHANCES/QPF: CONFIDENCE IS HIGH THAT SOME MUCH NEEDED
RAINFALL WILL FALL ACROSS THE SOUTH CAROLINA LOWCOUNTRY AND
SOUTHEAST GEORGIA FRIDAY INTO EARLY SUNDAY MORNING AS A STORM
SYSTEM IMPACTS THE REGION. A REGION OF SCATTERED TO NUMEROUS
SHOWERS, MOSTLY INDUCED BY ISENTROPIC ASCENT/WARM AIR ADVECTION
30-40 KT LOW-LEVEL JET, WILL DEVELOP FRIDAY BRINING A RISK FOR
MOSTLY LIGHT RAIN AMOUNTS. HEAVIER, POTENTIALLY MORE WIDESPREAD
RAINS ARE LIKELY SATURDAY INTO SATURDAY NIGHT AS LOW PRESSURE
APPROACHES AND THE AFOREMENTIONED STATIONARY FRONT OVER THE
LOWCOUNTRY BEGINS TO MEANDER NORTH. 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 1.50"
AND THE PRESENCE OF SOME SURFACE-BASED INSTABILITY SHOULD EASILY
SUPPORT SOME SPOTS RECEIVING OVER AN 0.50" OVER A 6-HOUR
PERIOD. THE STORM TOTAL QPF FROM FRIDAY THROUGH SUNDAY MORNING
IS 0.40-1.15" WITH THE HIGHEST TOTALS OCCURRING ACROSS FAR
INTERIOR SOUTHEAST GEORGIA INTO AREAS ADJACENT TO THE SOUTHERN
MIDLANDS AND THE CHARLESTON TRI-COUNTY. WHILE NOT EXCESSIVE,
THESE AMOUNTS WILL CERTAINLY HELP WITH THE SEVERE TO EXTREME
DROUGHT CONDITIONS THAT ARE IN PLACE.
SEVERE WEATHER: THE RISK FOR SEVERE WEATHER SATURDAY INTO
SATURDAY NIGHT IS CONDITIONAL ON HOW MUCH INSTABILITY CAN
DEVELOP IN THE WARM SECTOR. LOW-LEVEL WIND FIELDS LOOK STRONG
AND SUFFICIENTLY SHEARED WITH 0-6KM BULK SHEAR FORECAST TO
INCREASE TO 50-70 KT BY LATE SATURDAY AFTERNOON. THESE VALUES
WOULD CERTAINLY BE SUPPORTIVE OF A DAMAGING WIND/TORNADO THREAT
WITH ANY ORGANIZED CONVECTIVE CLUSTERS, BUT THE MAIN
UNCERTAINTY, AS IS TYPICAL THIS TIME OF YEAR, IS INSTABILITY.
THE 19/13Z NBM SHOWS THE RISK FOR SBCAPE >500 J/KG BY LATE
SATURDAY AFTERNOON IS GREATEST OVER INTERIOR SOUTHEAST GEORGIA
IN THE FAR SOUTHERN PARTS OF THE LOWCOUNTRY WITH PROBABILITIES
RUNNING 70-95%. PROBABILITIES ARE QUITE A BIT LOWER (25-50%)
FARTHER TO THE NORTH ACROSS THE INTERIOR PARTS OF THE LOWCOUNTRY
AND THE CHARLESTON TRI-COUNTY WHERE THERE IS MUCH MORE
UNCERTAINTY ON HOW FAR NORTH THE WARM FRONT WILL PROGRESS. AT
THIS TIME, CONFIDENCE IN AT LEAST ISOLATED SEVERE THUNDERSTORMS
IS GREATEST ACROSS INTERIOR SOUTHEAST GEORGIA, ROUGHLY IN THE
AREA SOUTH OF I-16 AND WEST OF I- 95 WITH CONFIDENCE DROPPING
OFF QUITE A BIT ACROSS THE LOWCOUNTRY DUE TO UNCERTAINTIES IN
WARM FRONT POSITIONING AND WHERE MORE SOUTHERLY TRAJECTORIES
FROM OFF THE COLDER ATLANTIC WATERS COULD HAVE A MORE
STABILIZING INFLUENCE. DAY 3 WFO GUIDANCE FROM THE SPC CURRENTLY
OUTLINES THE ENTIRE FORECAST AREA IN A MARGINAL RISK (LEVEL 1
OF 5) FOR SEVERE TSTMS WHICH LOOKS APPROPRIATE FOR THE CURRENT
SET UP AND LEVEL OF UNCERTAINTY. SHOULD THE RISK FOR HIGHER
INSTABILITY BE REALIZED, THEN THE RISK LEVEL MAY BE INCREASED IN
FUTURE FORECASTS.
ABOVE NORMAL/NEAR RECORD WARMTH: WELL ABOVE NORMAL TEMPERATURES
ARE LIKELY TO PERSIST THROUGH SATURDAY. HIGH TEMPERATURES
FRIDAY COULD GET CLOSE TO RECORD TERRITORY AT KCHS AND KSAV, BUT
CURRENT INDICATIONS ARE THEY WILL FALL JUST SHORT. WARM
OVERNIGHT LOWS TONIGHT AND AGAIN FRIDAY NIGHT COULD CHALLENGE
THE RECORD HIGH MINIMUMS, AGAIN MOST LIKELY AT KCHS AND KSAV.
SEE THE RECORD SECTION BELOW FOR THE SPECIFIC RECORDS.
KEY MESSAGE 2: COLD WEATHER WILL RETURN SUNDAY NIGHT INTO
TUESDAY NIGHT.
COLD HIGH PRESSURE WILL BUILD INTO THE REGION SUNDAY NIGHT AND
LINGER THROUGH THE MIDDLE OF NEXT WEEK. THIS WILL USHER IN A
RETURN OF MORE WINTER-LIKE CONDITIONS WITH SUB-FREEZING
TEMPERATURES LIKELY BOTH MONDAY AND TUESDAY MORNINGS. LINGERING
COLD AIR ADVECTION AND ENHANCED PRESSURE GRADIENT BETWEEN THE
HIGH BUILDING IN A DEPARTING LOW PRESSURE OFF THE MID-ATLANTIC
COAST COULD DRIVE WIND CHILLS DOWN INTO THE LOWER-MID 20S. THERE
IS ABOUT A 20-35% CHANCE FOR WIND CHILLS TO DROP BELOW THE COLD
WEATHER ADVISORY CRITERIA OF 20 DEGREES, SO THIS IS SOMETHING
THAT WILL CONTINUED TO BE WATCHED CLOSELY. HIGHS WILL ONLY
RECOVER TO THE UPPER 40S/LOWER 50S MONDAY WITH LOWS TUESDAY
MORNING DROPPING INTO THE MID-UPPER 20S AWAY FROM THE BEACHES
WITH WIND CHILLS IN THE MID 20S JUST ABOUT EVERYWHERE.
TEMPERATURES WILL BEGIN TO MODERATE TUESDAY INTO WEDNESDAY.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
GUSTY SOUTHWEST WINDS WILL CONTINUE THIS AFTERNOON BEFORE SUBSIDING
TO 10 KT AROUND SUNSET. A LIGHT ISLOLATED SHOWER COULD PASS
NEAR THE TERMINALS THIS EVENING INTO TONIGHT, ESPECIALLY AT
KSAV, SUPPORTING NO MORE THAN VCSH. GUIDANCE TRENDS TOWARD
LOWERING CIGS FRIDAY MORNING DUE TO MARINE STRATUS PUSHING OVER
KSAV AND KJZI, BRINGING MVFR/IFR CONDITIONS OR PERHAPS LIFR.
VISIBILITIES SHOULD REMAIN 5SM OR GREATER, BEING THAT WE DO NOT
ANTICIPATE DENSE FOG OVER THE TERMINALS. RAINFALL CHANCES
INCREASE FRIDAY EARLY AFTERNOON WITH SCATTERED SHOWERS, AS WELL
AS A RETURN OF GUSTY SOUTHWEST WINDS. REFINEMENTS ON TIMING OF
RAINFALL FRIDAY WILL BE NEEDED IN FUTURE TAFS.
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
THE MARINE ZONES WILL REMAIN BETWEEN HIGH PRESSURE CENTERED OVER THE
WESTERN ATLANTIC AND LOW PRESSURE OVER THE MIDWEST. THIS
PATTERN WILL SUPPORT SOUTHWEST WINDS GENERALLY AROUND 15-20 KT
WITH 3 TO 5 FT SEAS THROUGH TONIGHT, WITH SOME 6 FT SEAS MOVING
INTO THE CHARLESTON COUNTY NEARSHORE WATERS. THE PRESSURE
GRADIENT PINCHES ON FRIDAY, AND WIND GUSTS ACROSS THE COASTAL
WATERS WILL RANGE 20-25 KT. SMALL CRAFT ADVISORIES HAVE BEEN
ISSUED FOR THE CHARLESTON COUNTY NEARSHORE WATERS, INCLUDING THE
HARBOR, AND THE OFFSHORE GEORGIA WATERS FROM 20-60 NM FOR GUSTY
WINDS THROUGH FRIDAY EVENING.
A FRONTAL WAVE IS FORECAST TO DEVELOP OVER THE I-20
CORRIDOR OF THE DEEP SOUTH FRIDAY NIGHT, 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 COULD LINGER INTO MONDAY.
SEA FOG: THE SURFACE PRESSURE PATTERN WILL SUPPORT SOUTHWEST WINDS,
GENERALLY PARALLEL TO THE COAST THROUGH THE REST OF THE WEEK.
SOUTHWEST WINDS WILL CONTINUE TO USHER IN MOIST AIR WITH DEWPOINTS
IN THE UPPER 50S TO LOW 60S THROUGH SATURDAY. BUOY OBSERVATIONS
INDICATE THAT THE NEARSHORE WATER TEMPERATURES GENERALLY RANGE IN
THE LOW 50S. GIVEN PARALLEL WINDS AND DEWPOINTS NEARLY 10 DEGREES
WARMER THAN THE WATER TEMPERATURES, AT LEAST PATCHY SEA FOG IS
EXPECTED TO DEVELOP. PROBABILISTIC GUIDANCE SHOWS LIKELY VALUES OF
VISIBILITY LESS THAN 0.5 MILES AT TIMES FRIDAY AND SATURDAY. ON THE
OTHER HAND, THE SEA FOG POTENTIAL WILL BE LIMITED BY GUSTY
CONDITIONS AND ROUNDS OF SHOWERS WHICH COULD MIX OUT ANY FOG FOR
PERIODS OF TIME. MARINE DENSE FOG ADVISORIES COULD BE NEEDED.
ADDITIONALLY, SEA FOG COULD ADVECT ONSHORE AND IMPACT THE BEACHES
AND NEARBY COASTAL LOCATIONS, WITH VISIBILITIES DROPPING TO 1
MILE OR LESS AT TIMES. WE WILL MONITOR THE NEED FOR DENSE FOG
ADVISORIES OVER LAND.
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...NONE.
MARINE...NONE.
BRS/ST
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