473
FXUS62 KCHS 221736
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1236 PM EST MON DEC 22 2025
SYNOPSIS
HIGH PRESSURE WILL PREVAIL THROUGH THE REMAINDER OF THE HOLIDAY
WEEK.
NEAR TERM /THROUGH TONIGHT/
WEAK RIDGING LOCATED OVER THE SOUTHEASTERN STATES IN THE MID-
LEVELS WILL YIELD NORTHWESTERLY FLOW ACROSS THE SC LOWCOUNTRY
AND SE GA THROUGH THIS AFTERNOON AND TONIGHT. AT THE SURFACE,
15Z SURFACE ANALYSIS SHOWS THE CENTER OF HIGH PRESSURE LOCATED
OVER THE NC/SC BORDER. GIVEN THE DOMINATING HIGH PRESSURE BOTH
ALOFT AND IN THE UPPER LEVELS, ANOTHER QUIET DAY IS ON TAP. THIS
MORNING'S 12Z KCHS RAOB SOUNDING ONLY SHOWED A PWAT OF 0.3", SO
A DRY FORECAST WILL REMAIN. HIGH TEMPERATURES TODAY WILL REACH
INTO THE UPPER 50S TO LOW 60S, WARMEST SOUTH OF I-16 IN SE GA.
WITH NO CHANGES ANTICIPATED IN THE SYNOPTIC SET UP THROUGH THE
OVERNIGHT PERIOD, THE QUIET PATTERN WILL CONTINUE. WINDS ARE
FORECAST TO GO LIGHT AND VARIABLE SHORTLY AFTER NIGHTFALL,
HOWEVER GIVEN SOME HIGH CLOUDS RADIATIONAL COOLING CONDITIONS
WILL NOT BE IDEAL. LOW TEMPERATURES ARE FORECAST TO DIP INTO THE
LOWER 40S INLAND WITH LOW 50S ALONG THE COASTAL COUNTIES. FOG
OVERNIGHT/INTO TUESDAY MORNING IS NOT A CONCERN AT THIS TIME,
AS NBM AND HREF PROBABILITIES FOR VISIBILITIES <3 MILES ARE ALL
<10%. ADDITIONALLY, CONDENSATION PRESSURE DEFICITS ARE NOT
FAVORABLE FOR FOG FORMATION EITHER.
SHORT TERM /TUESDAY THROUGH THURSDAY/
TUESDAY THROUGH CHRISTMAS, SHORT TERM GUIDANCE INDICATES THAT A
STRONG H5 RIDGE WILL REMAIN CENTERED OVER THE GULF, WITH THE RIDGE
AXIS EXTENDING ACROSS THE CENTRAL CONUS. DURING THE PERIOD, AN
AMPLIFIED WAVE WILL RIPPLE ACROSS NEW ENGLAND, PUSHING OVER THE NORTH
ATLANTIC ON CHRISTMAS EVE. THIS PATTERN WILL KEEP THE FORECAST AREA
UNDER DRY NW FLOW ALOFT. AT THE SFC, HIGH PRESSURE SHOULD REMAIN
CENTERED OVER THE NORTHERN GULF COAST, WITH A POSSIBLE DRY COLD
FRONT LATE CHRISTMAS. OVERALL, THE FORECAST WILL FEATURE DRY AND
VERY MILD CONDITIONS THROUGH THE SHORT TERM PERIOD. TEMPERATURE
SHOULD TREND WARMER THROUGH CHRISTMAS, WITH CHRISTMAS TEMPERATURES
FEATURING LOWS AROUND 50 AND HIGHS IN THE MID TO UPPER 70S.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/
VERY MILD AND DRY WEATHER WILL CONTINUE ACROSS THE FORECAST AREA
THROUGH THIS WEEKEND. THE H5 PATTERN WILL CONTINUE TO FEATURE A
SHALLOW LONGWAVE RIDGE ACROSS THE SOUTHERN CONUS. HIGH PRESSURE WILL
REMAIN ACROSS THE SOUTHEAST U.S. THROUGH SATURDAY NIGHT. BY SUNDAY,
A COLD FRONT WILL APPROACH FROM THE WEST, RETURN FLOW WILL KEEP
TEMPERATURES IN THE MID TO UPPER 70S. THE COLD FRONT IS TIMED TO
PASS OVER THE REGION SUNDAY EVENING AND NIGHT. ISOLATED RAIN SHOWERS
GUSTY NW WINDS SHOULD ACCOMPANY THE PASSAGE OF THE FRONT.
TEMPERATURES MAY COOL BY 15 DEGREES BY MONDAY, WITH HIGHS NEAR 60
DEGREES.
AVIATION /18Z MONDAY THROUGH SATURDAY/
PREVAILING VFR THROUGH THE 18Z TAF PERIOD. NE WINDS ARE FORECAST
TO GUST TO AROUND 20 KNOTS THIS AFTERNOON, GOING LIGHT AND
VARIABLE OVERNIGHT.
EXTENDED AVIATION OUTLOOK: A BRIEF PERIOD OF MVFR CIGS/VSBYS WILL BE
POSSIBLE WEDNESDAY MORNING DUE TO FOG OR STRATUS DEVELOPMENT.
OTHERWISE, EXPECT VFR CONDITIONS TO PREVAIL.
MARINE
THIS AFTERNOON AND TONIGHT: HIGH PRESSURE CENTERED OVER THE
SC/NC BORDER WILL DOMINATE THROUGH THE OVERNIGHT PERIOD.
ELEVATED NE WINDS ARE FORECAST THIS AFTERNOON ACROSS ALL MARINE
WATERS, AS THE PRESSURE GRADIENT BECOMES PINCHED BETWEEN THE
DEPARTING COLD FRONT TO THE SOUTH AND THE HIGH PRESSURE BUILDING
INTO THE REGION FROM THE WEST. GUSTS ACROSS THE MARINE WATERS
ARE FORECAST TO BE IN THE 25-30 KT RANGE, WITH 20-25 KT IN THE
CHARLESTON HARBOR. ADDITIONALLY, ELEVATED SEAS ARE BEING
OBSERVED ACROSS THE REGION, WITH 5 TO 6 FT ACROSS THE NEARSHORE
WATERS AND 6 TO 7 FT IN THE 20 TO 60 NM OFFSHORE GA WATERS. A
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL MARINE WATERS
OUTSIDE OF THE CHARLESTON HARBOR INTO TONIGHT.
TUESDAY: SMALL CRAFT ADVISORY WILL CONTINUE ACROSS THE OUTER GEORGIA
WATERS THROUGH TUESDAY AFTERNOON DUE TO LINGERING 6 FT SEAS. MARINE
CONDITIONS THEN IMPROVE TUESDAY EVENING, WITH SOUTHWESTERLY WINDS
AROUND 10 KTS AND SEAS DROPPING TO 4 FT.
WEDNESDAY ONWARD: HIGH CONFIDENCE IN NO MARINE HEADLINES. THE
PATTERN WILL SUPPORT WINDS AROUND 10 KTS AND SEAS BETWEEN 2 TO 4
FT.
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ350-352-
354.
SMALL CRAFT ADVISORY UNTIL 6 PM EST TUESDAY FOR AMZ374.
NEAR TERM...CPM
SHORT TERM...NED
LONG TERM...NED
AVIATION...CPM/NED
MARINE...CPM/NED
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