334
FXUS62 KCHS 210033
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
733 PM EST THU NOV 20 2025
SYNOPSIS
DRY HIGH PRESSURE IS EXPECTED TO PREVAIL ACROSS THE AREA
THROUGH THE REST OF THE WEEK. A COLD FRONT IS EXPECTED TO SWEEP
ACROSS THE REGION SATURDAY NIGHT, FOLLOWED BY MORE HIGH
PRESSURE EARLY NEXT WEEK.
NEAR TERM /UNTIL 6 AM FRIDAY MORNING/
TONIGHT: A WEAK FRONT WILL SLOWLY SLIP SOUTH ALONG THE GA/SC COAST,
THEN BECOME STATIONARY NEAR THE SAVANNAH RIVER THIS EVENING, HELPING
SET UP AN ENVIRONMENT CONDUCIVE FOR FOG DEVELOPMENT OVERNIGHT.
LATEST GUIDANCE INDICATES LOW CONDENSATION PRESSURE DEFICITS AND
WEAK LOW-LVL WIND FIELDS ACROSS A MAJORITY OF THE LOCAL AREA
OVERNIGHT WHILE SFC WINDS REMAIN LIGHT/CALM FOR THE BULK OF THE
NIGHT. THESE CONDITIONS ALONG WITH NEARSHORE WATER TEMPERATURES (59-
63 DEGREES) ABOUT A DEGREE COOLER THAN EXPECTED DEWPOINTS OVERNIGHT
SUGGEST THE POTENTIAL FOR AREAS OR EVEN WIDESPREAD FOG TO DEVELOP
ACROSS MOST LAND ZONES AFTER MIDNIGHT (STRATUS BUILD DOWN AND
RADIATIONAL COOLING COMPONENTS). SOME FOG SHOULD BECOME DENSE FOR A
FEW TO SEVERAL HOURS LATER TONIGHT, PERSISTING THROUGH DAYBREAK
FRIDAY. A DENSE FOG ADVISORY COULD BE REQUIRED FOR A LARGE PORTION
OF THE AREA OVERNIGHT AND COULD NEED TO BE ISSUED AS EARLY AS MID-
LATE EVENING BASED ON TRENDS/OBSERVATIONS. LOW TEMPERATURES WILL
GENERALLY RANGE IN THE MID-UPPER 50S.
SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/
SHORT TERM GUIDANCE SHOWS A STRONG, NEARLY 590 DM, RIDGE CENTERED
OVER THE GULF ON FRIDAY. NAEFS INDICATES THAT FRIDAY, LLVL
TEMPERATURES ACROSS PORTIONS OF THE SOUTHEAST U.S. WILL APPROACH 2
UNITS OF STANDARDIZED ANOMALY. GIVEN THE STRONG RIDGE OVER THE
REGION, TEMPERATURES WILL REMAIN GENERALLY 10 TO 12 DEGREES ABOVE
NORMAL WITH NO PRECIPITATION. HIGH TEMPERATURES FRIDAY WILL REACH
NEAR RECORD HIGHS (SEE CLIMATE SECTION), WITH NEAR 80 ACROSS THE SC
LOWCOUNTRY TO THE LOW TO MID 80S ACROSS SE GA.
GUIDANCE INDICATED THAT THE H5 RIDGE WILL GRADUALLY FLATTEN ALONG
THE ATLANTIC COAST BY LATE DAY, RESULTING IN AN EVENING ARRIVAL OF
THE COLD FRONT. THE NBM BASED FORECAST IS SIDING WITH THE SLOWER
GUIDANCE, FEATURING NEAR RECORD HIGH TEMPERATURES AND AFTERNOON SCHC
POPS FOR SHOWERS ACROSS THE EXTREME INLAND ZONES. TEMPERATURES MAY
VERIFY A DEGREE OR TWO WARMER THAN FRIDAY.
GFS INDICATES THAT H85 TEMPERATURES ACROSS THE REGION WILL COOL BY 3
TO 4 DEGREES IN THE WAKE OF THE COLD FRONT SATURDAY NIGHT.
CONDITIONS SHOULD DRY FROM THE TOP-DOWN, RESULTING IN MOSTLY CLEAR
TO PARTLY CLOUDY CONDITIONS. LOW TEMPERATURES SUNDAY MORNING ARE
FORECAST TO RANGE IN THE MID TO UPPER 50S. HIGH TEMPERATURES ARE
EXPECTED TO REMAIN NEAR NORMALS, WITH NEAR 70 ACROSS THE SC
LOWCOUNTRY TO THE MID 70S ACROSS SE GA.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/
EARLY NEXT WEEK, MEDIUM RANGE GUIDANCE INDICATES THAT THE H5 RIDGE
AXIS WILL RIPPLE ACROSS THE REGION ON MONDAY. CONDITIONS WILL REMAIN
DRY WITH MODERATING TEMPERATURES. THROUGH MID-WEEK, THE H5 PATTERN
IS FORECAST TO FEATURE A 588 DM RIDGE OVER THE BAHAMAS AS A LONGWAVE
TROUGH DEVELOPS OVER THE GREAT PLAINS. A LARGE LOW PRESSURE SYSTEM
OVER EASTERN CANADA MAY SWEEP AN ELONGATED FRONT ACROSS THE REGION
INTO THE MID-WEEK. TUESDAY AND WEDNESDAY, THE FORECAST WILL FEATURE
ABOVE-NORMAL TEMPERATURES AND SCHC TO CHC POPS FOR SHOWERS.
AVIATION /00Z FRIDAY THROUGH TUESDAY/
A WEAK FRONT WILL STALL AROUND THE SAVANNAH RIVER TONIGHT, SETTING
UP AN ENVIRONMENT CONDUCIVE FOR FOG AT CHS/JZI/SAV TERMINALS
OVERNIGHT.
AT CHS/JZI, TEMPO MVFR CIGS ARE IN PLACE FROM 02-05Z FRIDAY,
FOLLOWED BY PREVAILING IFR CONDITIONS BETWEEN 04-05Z TO 13Z FRIDAY
FOR LOW CIGS AND POTENTIALLY DENSE FOG BETWEEN THE 08Z-12Z FRIDAY
TIMEFRAME. CONDITIONS SHOULD THEN IMPROVE TO MVFR AROUND 13Z FRIDAY,
THEN TO VFR AROUND 17-18Z FRIDAY AS CLOUDS BEGIN TO MIX OUT/ERODE.
VFR CONDITIONS SHOULD THEN PERSIST THROUGH 00Z SATURDAY.
AT SAV, PREVAILING MVFR CIGS ARE ANTICIPATED BY AROUND 03Z, WITH
DETERIORATING CONDITIONS TO IFR BY AROUND 05Z FRIDAY. LOW CIGS AND
DENSE FOG ARE MORE LIKELY BETWEEN 07Z-14Z FRIDAY WITH VSBY
RESTRICTIONS POSSIBLY BELOW 1/2 SM AND CIGS BELOW 500 FT. CONDITIONS
SHOULD THEN IMPROVE TO MVFR AROUND 15Z FRIDAY, THEN TO VFR AROUND 17-
18Z FRIDAY AS CLOUDS BEGIN TO MIX OUT/ERODE. VFR CONDITIONS SHOULD
THEN PERSIST THROUGH 00Z SATURDAY.
EXTENDED AVIATION OUTLOOK: PREVAILING VFR. IT IS POSSIBLE THAT
PERIODS OF GROUND FOG MAY DEVELOP DURING THE PRE-DAWN HOURS
THROUGH SATURDAY.
MARINE
TONIGHT: THE PRIMARY CONCERN OVERNIGHT WILL BE THE POTENTIAL
DEVELOPMENT OF FOG AND LOW CLOUDS ACROSS THE NEARSHORE WATERS. A
WEAK FRONT WILL SLOWLY SLIP SOUTH ALONG THE GA/SC COAST, EXPECTED TO
BECOME STATIONARY JUST NORTH OF THE SAVANNAH RIVER THIS EVENING.
AREAS TO PATCHY FOG COULD DEVELOP ACROSS THE GA NEARSHORE WATERS
THIS EVENING, THEN SPREAD NORTH LATE TONIGHT. IT IS POSSIBLE THAT A
DENSE FOG ADVISORY COULD BE ISSUED TONIGHT. OTHERWISE, CONDITIONS
WILL FEATURE WINDS AROUND 5 KTS WITH 1-2 FT WAVE HEIGHTS.
FRIDAY THROUGH SUNDAY: CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA THROUGH THE PERIOD. BROAD HIGH PRESSURE SHOULD
REMAIN ACROSS MARINE ZONES FRIDAY THROUGH MUCH OF SATURDAY, THEN A
WEAK COLD FRONT SHOULD SWEEP ACROSS THE REGION LATE SATURDAY.
SOUTHWEST WINDS AHEAD OF THE FRONT ARE EXPECTED TO GRADUALLY
STRENGTHEN, REACHING 10 TO 15 KTS ON SATURDAY. BEHIND THE FRONT,
WINDS SHOULD VEER FROM NORTHWEST SATURDAY NIGHT, THEN NORTHEAST ON
SUNDAY BETWEEN 10 TO 15 KTS. SEAS THROUGH THE PERIOD SHOULD FAVOR
VALUES BETWEEN 1 TO 2 FT.
CLIMATE
RECORD HIGH TEMPERATURES:
NOVEMBER 20:
KCHS: 82/1942
KCXM: 78/1900
KSAV: 83/1942
NOVEMBER 21:
KSAV: 82/2011
NOVEMBER 22:
KCHS: 83/1942
KCXM: 79/1997
KSAV: 82/1997
CHS WATCHES/WARNINGS/ADVISORIES
GA...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...DPB/NED
SHORT TERM...NED
LONG TERM...NED
AVIATION...DPB
MARINE...DPB/NED
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