993
FXUS62 KCHS 121831
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
131 PM EST FRI DEC 12 2025
SYNOPSIS
HIGH PRESSURE WILL PREVAIL THROUGH SATURDAY, THEN AN ARCTIC
COLD FRONT WILL SWEEP THROUGH LATE SUNDAY. DRY HIGH PRESSURE
WILL THEN REBUILD INTO THE REGION.
NEAR TERM /THROUGH TONIGHT/
THE FORECAST AREA WILL REMAIN UNDER A BROAD H5 TROUGH THROUGH
TONIGHT. A WEAK COLD FRONT SHOULD REMAINED POSITIONED UPSTREAM OF
THE REGION TONIGHT. THIS PATTERN WILL SUPPORT LIGHT SOUTHWEST WINDS
ACROSS THE FORECAST AREA TONIGHT. CONDITIONS SHOULD REMAIN DRY WITH
MOSTLY CLEAR SKIES. LOW TEMPERATURES TONIGHT ARE FORECAST TO RANGE
FROM THE UPPER 30S INLAND TO THE LOW TO MID 40S ALONG THE COAST.
SHORT TERM /SATURDAY THROUGH MONDAY/
..BITTER COLD TEMPERATURES EXPECTED SUNDAY NIGHT
THE MOST IMPACTFUL PART OF THIS PERIOD WILL BE THE BITTER COLD
TEMPERATURES EXPECTED BEHIND AN ARCTIC COLD FRONT SUNDAY.
SATURDAY: AS HIGH PRESSURE CONTINUES TO SITUATE ITSELF ACROSS THE
REGION, ZONAL UPPER-LVL FLOW AND LOW-LVL SOUTHWEST WINDS WILL
DOMINATE THE FORECAST. EXPECT HIGHS ON SATURDAY TO WARM TO ABOVE
NORMAL IN THE MID 60S TO LOW 70S. THERE WOULD BE THE WARMEST
TEMPERATURES WE'VE HAD SO FAR THIS MONTH IN DECEMBER! A MILD NIGHT
IS IN-STORE FOR SATURDAY AS A DEEP UPPER TROUGH TAKES SHAPE OVER THE
GREAT LAKES AND INTO THE MID-ATLANTIC. WITH SOUTHWEST LOW-LVL FLOW,
LOWS WILL STAY IN THE UPPER 40S INLAND TO THE LOW TO MID 50S CLOSER
TO THE COASTLINE.
SUNDAY: AS THE UPPER-LVL TROUGH GRADUALLY SHARPENS EASTWARD, AN
ASSOCIATED ARCTIC FRONT WILL APPROACH THE REGION ON SUNDAY MORNING.
MARGINAL MOISTURE WILL BE AVAILABLE WITH PWAT VALUES BELOW 0.5
INCHES, THUS OTHER THAN SOME ISOLATED SHOWERS, NOT EXPECTED MUCH IN
TERMS OF PRECIPITATION AHEAD OF THE FRONT. TEMPERATURES WILL LIKELY
REACH THEIR HIGHEST THROUGH EARLY AFTERNOON, THEN BEGIN TO FALL
THROUGH THE 50S BEHIND THE STRONG COLD FRONT THROUGH THE REMAINDER
OF THE AFTERNOON. THROUGH THE OVERNIGHT, EXPECT TEMPERATURES TO DROP
INTO THE UPPER TEENS TO LOW 20S AS NORTH-NORTHWESTERLY WINDS DRIVE
ARCTIC TEMPERATURES SOUTHWARD THROUGH THE REGION. THEREFORE, AN
EXTREME COLD WATCH HAS BEEN ISSUED FOR SOUTH CAROLINA LOWCOUNTRY AND
INLAND SOUTHEAST GEORGIA FOR SUNDAY EVENING THROUGH MONDAY MORNING.
ALSO, A COLD WEATHER ADVISORY HAS BEEN ISSUED FOR MOST OF SOUTHEAST
GEORGIA AND THE LOWER SOUTH CAROLINA LOWCOUNTRY FOR SUNDAY EVENING
THROUGH MONDAY MORNING AS WELL. THESE TYPE OF COLD TEMPERATURES WILL
BE VERY HAZARDOUS, AND COULD CAUSE ISSUES WITH EXPOSED
PIPES/PLUMBING.
MONDAY: AFTER THE PASSAGE OF THE FRONT, A SURFACE RIDGE SHIFTS
ACROSS THE REGION WITH LIGHTER NORTH-NORTHEASTERLY WINDS. EVEN WITH
SUNNY SKIES, POST-FROPA CONDITIONS WILL KEEP TEMPERATURES BELOW
NORMAL WITH HIGHS ONLY REACHING IN THE UPPER 30S TO LOW 40S!
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
AS THE SURFACE RIDGE CONTINUES TO SIT OVER THE REGION, EXPECT LIGHT
WINDS WITH MOSTLY CLEAR SKIES ON MONDAY NIGHT. IT'LL BE A TAD WARMER
OVERNIGHT ON MONDAY WITH TEMPERATURES IN THE LOW 20S ACROSS THE
INLAND COUNTIES AND MID 20S TO UPPER 20S ALONG THE COASTLINE. IT'S
IMPORTANT TO NOTE THAT PATCHY TO SCATTERED FROST COULD BE POSSIBLE
ON MONDAY NIGHT AS WELL. THEREAFTER, TEMPERATURES WILL WARM BACK UP
TO NEAR NORMAL THROUGHOUT THE WEEK AS ZONAL FLOW TAKES OVER THE
FORECAST. THERE ARE MODEL DIFFERENCES WITH PRECIP. CHANCES LATE IN
THE WEEK AS COASTAL TROUGH TRIES TO FORM NEARBY.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
VFR CONDITIONS WILL PREVAIL AT KCHS, KJZI, AND KSAV THROUGH 18Z
SATURDAY.
EXTENDED AVIATION OUTLOOK: BEHIND A STRONG ARCTIC COLD FRONT, EXPECT
BREEZY WINDS ON SUNDAY INTO MONDAY MORNING. OTHERWISE, SHOULD BE VFR
CONDITIONS.
MARINE
TONIGHT: WEST WINDS SHOULD REMAIN AROUND 10 KTS OVERNIGHT. WAVE
HEIGHTS BETWEEN 1 TO 2 FT.
SATURDAY INTO SATURDAY NIGHT: FAIR CONDITIONS EXPECTED ACROSS THE
MARINE ZONES. WINDS SHOULD REMAIN BETWEEN 10 TO 15 KTS. SEAS BETWEEN
1 TO 2 FT ON SATURDAY, INCREASING TO 1 TO 3 FT BY LATE SATURDAY
NIGHT.
A PASSING ARCTIC COLD FRONT WILL RESULT IN STRENGTHENING WINDS AND
BUILDING SEAS LATE SUNDAY THROUGH MONDAY. WINDS ARE FORECAST TO PEAK
SUNDAY EVENING AND NIGHT, WITH GUSTS IN THE MID 20S TO LOW 30S
ACROSS THE CHS HARBOR AND NEARSHORE WATERS OF GA AND LOWER SC. IN
ADDITION, WIND GUSTS ACROSS THE CHARLESTON COUNTY NEARSHORE AND
OUTER GA WATERS MAY SEE PERIODS OF GALE FORCE. AS A RESULT, WAVE
HEIGHTS WILL INCREASE TO 5-6 FT ACROSS THE NEARSHORE WATERS WITH 7-9
FT ACROSS THE OUTER GA WATERS. THE MARINE CONDITIONS MAY BE
HIGHLIGHTED WITH A GALE WATCH OR SMALL CRAFT ADVISORY.
TUESDAY, WINDS AND SEAS ARE EXPECTED TO FALL BACK BELOW CRITERIA
LEVELS AS HIGH PRESSURE BUILDS OVER THE WATERS. WINDS GENERALLY 15
KNOTS OR LESS AND SEAS 2 TO 4 FEET, HIGHEST WELL OFFSHORE.
CLIMATE
RECORD LOW TEMPERATURES:
DECEMBER 15:
KCHS: 15/1962
KCXM: 23/1943
KSAV: 19/1962
RECORD LOW MAXIMUM TEMPERATURES:
DECEMBER 15:
KCHS: 39/1943
KCXM: 38/1904
KSAV: 38/1904
CHS WATCHES/WARNINGS/ADVISORIES
GA...EXTREME COLD WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING
FOR GAZ087-088.
COLD WEATHER ADVISORY FROM 10 PM SUNDAY TO 10 AM EST MONDAY
FOR GAZ099>101-114>119-137>141.
SC...EXTREME COLD WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING
FOR SCZ040-042>045-050-052.
COLD WEATHER ADVISORY FROM 10 PM SUNDAY TO 10 AM EST MONDAY
FOR SCZ047>049-051.
MARINE...NONE.
NEAR TERM...NED
SHORT TERM...DENNIS
LONG TERM...DENNIS
AVIATION...DENNIS/NED
MARINE...NED
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