570
FXUS62 KCHS 130635
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
135 AM EST SAT DEC 13 2025
SYNOPSIS
HIGH PRESSURE WILL PREVAIL TODAY, THEN AN ARCTIC COLD FRONT
WILL SWEEP THROUGH SUNDAY. DRY HIGH PRESSURE WILL THEN REBUILD
INTO THE REGION.
NEAR TERM /THROUGH TONIGHT/
TODAY: ALOFT, A ZONAL WEST-SOUTHWEST FLOW WILL PREVAIL ACROSS THE
SOUTHEAST UNITED STATES IN ADVANCE OF A LARGE TROUGH DIGGING ACROSS
THE NORTH-CENTRAL UNITED STATES AND MIDWEST. AT THE SFC, DRY HIGH
PRESSURE WILL DOMINATE THE PATTERN, RESULTING IN A LIGHT SOUTHWEST
WIND AND WARMER CONDITIONS UNDER SUNNY/MOSTLY SUNNY SKIES. IN
GENERAL, HIGH TEMPS SHOULD RANGE IN THE MID-UPPER 60S ACROSS
SOUTHEAST SOUTH CAROLINA AND AROUND 70 DEGREES ACROSS SOUTHEAST
GEORGIA. SHOULD THESE TEMPS OCCUR, IT WILL BE THE WARMEST DAY
EXPERIENCED IN THE MONTH OF DECEMBER THUS FAR.
TONIGHT: ALOFT, A ZONAL FLOW PREVAILS FOR MUCH OF THE NIGHT IN
ADVANCE OF THE DIGGING TROUGH ACROSS THE MIDWEST. AT THE SFC, THE
ATLANTIC HIGH WILL EXTEND ACROSS THE SOUTHEAST, WHILE SOME TROUGHING
DEVELOPS NORTH AND INLAND OVERNIGHT. ALTHOUGH THE PRESSURE GRADIENT
REMAINS MODEST BETWEEN THESE FEATURES, CONDITIONS WILL REMAIN
NOTICEABLY MORE MILD THAN THE PREVIOUS NIGHT WHILE A LIGHT
SOUTHWESTERLY WIND ADVECTS WARMER AIR INTO THE REGION WELL IN
ADVANCE OF A COLD FRONT ARRIVING THE NEXT DAY. IN GENERAL, LOWS
SHOULD ONLY DIP INTO THE UPPER 40S/LOWER 50S, REMAINING WARMEST
ALONG THE COAST. SOME GUIDANCE EVEN HINTS AT THE POTENTIAL FOR SOME
PATCHY FOG LATE AS SFC DEWPTS INCREASE. HOWEVER, THE ARRIVAL OF SOME
CLOUDS SHOULD LIMIT THE COVERAGE OF FOG LATE NIGHT.
SHORT TERM /SUNDAY THROUGH TUESDAY/
..BITTER COLD TEMPERATURES EXPECTED MUCH OF THIS PERIOD
SUNDAY: A STRONG/ARCTIC COLD FRONT IS STILL SHOWN BY ALL MODELS TO
PUSH THROUGH THE REGION BETWEEN LATE SUNDAY MORNING AND EARLY/MID
SUNDAY AFTERNOON. HIGH TEMPERATURES OF 60-65 WILL LIKELY BE REACHED
JUST AHEAD OF THE FRONT THROUGH EARLY AFTERNOON, THEN BEGIN FALLING
THROUGH THE 50S DURING THE AFTERNOON BEHIND THE FRONT. LATEST
BLENDED GUIDANCE HAS INCREASED POPS TO LOW END CHANCE LEVELS OVER
MUCH OF OUR SC ZONES, AND 15-24% FOR MUCH OF OUR GA ZONES. ANY
PRECIP. ALONG AND AHEAD OF THE FRONT WILL BE IN THE FORM OF SHOWERS,
SINCE IT WILL BE TOO WARM AT THAT TIME FOR ANY FROZEN PRECIP.. QPF
VALUES ARE EXPECTED TO BE GENERALLY LESS THAN 0.10 INCH. WEST-
SOUTHWEST WINDS IN THE MORNING, WILL VEER SHARPLY TO NORTHWEST AND
INCREASE BEHIND THE FRONT BY AFTERNOON. WIND GUSTS OF 20-25 MPH WILL
BE POSSIBLE. BY SUNDAY NIGHT, A STRONG ARCTIC SURFACE RIDGE WILL
BUILD FROM THE NORTHWEST, KEEPING NORTHWEST TO NORTH WINDS THROUGH
THE NIGHT. TEMPERATURES EXPECTED TO DROP INTO THE UPPER TEENS WELL
INLAND, AND LOWER TO MID 20S ELSE WHERE, WARMEST NEAR THE COAST.
WIND CHILL VALUES ALL AREAS EXPECTED TO REACH COLD WEATHER ADVISORY
LEVELS /20 DEGREES TO 11 DEGREES/ ALL AREAS, AND COULD DIP TO 10
DEGREES OR COLDER OVER PORTIONS OF THE NORTHERN AREA, WHERE WE
CURRENTLY HAVE A EXTREME COLD WATCH IN PLACE.
MONDAY: DEEP RIDGING IS SHOWN BY ALL MODELS TO SETTLE OVER THE
REGION, WITH LIGHTER WINDS AND MOSTLY SUNNY/SUNNY SKIES. DESPITE
FULL SUN, GUIDANCE CONTINUES TO HOLD HIGH TEMPERATURES TO 40 TO 45,
15 TO 20 DEGREES BELOW NORMAL! MONDAY NIGHT, HIGH PRESSURE WILL
START CENTERED OVER THE REGION, THEN SLOWLY SHIFT OFFSHORE BY LATE
NIGHT. LIGHT WINDS, CLEAR SKIES AND DRY LOW LEVELS SHOULD ALLOW FOR
STRONG RADIATIONAL COOLING. VERY COLD TEMPERATURES AGAIN EXPECTED,
WITH LOWS AROUND 20 WELL INLAND, TO THE MID 20S TO NEAR 30 CLOSER TO
THE COAST.
TUESDAY: THIS PERIOD BEGINS THE MODERATION IN TEMPERATURES, WITH THE
SURFACE RIDGE SHIFTING FURTHER OFFSHORE, ALLOWING FOR LOW LEVEL
WINDS TO VEER TO SOUTHWEST BY AFTERNOON. UNDER MOSTLY SUNNY SKIES,
HIGHS REBOUNDING INTO THE 50S ALL AREAS, WHICH IS STILL A TAD BELOW
NORMAL.
LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/
ALL GLOBAL AND BLENDED MODEL SOLUTIONS SHOW THAT THE LARGE
SCALE/SYNOPTIC PATTERN SHIFTS TO ZONAL, WITH MODERATING TEMPERATURES
THROUGH THE PERIOD. TUESDAY NIGHT WILL BE THE COLDEST PERIOD, WITH
FREEZING TEMPERATURES AGAIN EXPECTED INLAND, AND MID TO UPPER 30S
CLOSER TO THE COAST. THEN WEDNESDAY THROUGH SATURDAY, TEMPERATURES
CONTINUE TO WARM, WITH TEMPERATURES NEAR NORMAL ON WEDNESDAY, TO
ABOVE NORMAL THURSDAY THROUGH SATURDAY. THE BIGGEST FORECAST ISSUE
FOR THIS PERIOD WILL BE HOW TO HANDLE THE MODEL DIFFERENCES WITH
CHANCES FOR PRECIP. LATE IN THE PERIOD. SOME MODELS INDICATE THE
POTENTIAL FOR ANOTHER COLD FRONT TO APPROACH THE AREA LATER THURSDAY
AND EARLY FRIDAY, BUT TIMING AND AMOUNT OF DEEP LAYER MOISTURE VARY
BETWEEN MODELS. FOR NOW, THE BLENDED MODEL SOLUTION BRINGS BACK
SLIGHT CHANCE POPS FOR THURSDAY AND THURSDAY NIGHT. THIS WILL LIKELY
NEED ADJUSTING WITH LATER FORECASTS.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
VFR CONDITIONS ARE EXPECTED AT CHS/JZI/SAV TERMINALS THROUGH 06Z
SUNDAY.
EXTENDED AVIATION OUTLOOK: GENERALLY VFR CONDITIONS ARE EXPECTED
SUNDAY THROUGH MID WEEK. HOWEVER, A STRONG ARCTIC COLD FRONT
WILL MOVE THROUGH ON SUNDAY, WITH GUSTY WINDS SUNDAY AFTERNOON
INTO SUNDAY EVENING.
MARINE
TODAY AND TONIGHT: HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN
FOR THE DAY AND NIGHT, LEADING TO QUIET MARINE CONDITIONS ACROSS
LOCAL WATERS TODAY, BUT A NOTICEABLE UPTICK IN WIND SPEEDS AS A
MODEST PRESSURE GRADIENT DEVELOPS LATE NIGHT. IN GENERAL, SOUTH-
SOUTHWEST WINDS SHOULD TOP OUT AROUND 10 KT TODAY, THEN INCREASE TO
10-15 KT THIS EVENING. A FEW WIND GUSTS UP TO 20 KT ARE POSSIBLE
ACROSS NORTHERN SOUTH CAROLINA WATERS AND OUTER GEORGIA WATERS LATE
NIGHT. SEAS WILL RANGE BETWEEN 1-2 FT TODAY, THEN BUILD ABOUT A FOOT
OVERNIGHT.
..HAZARDOUS MARINE CONDITIONS LATER SUNDAY INTO MONDAY
A STRONG ARCTIC COLD FRONT WILL MOVE THROUGH THE WATERS ON
SUNDAY, LIKELY PASSING THROUGH THE ENTIRE REGION BY LATE AFTERNOON.
SOUTHWEST WINDS WILL VEER SHARPLY TO NORTHWEST DURING SUNDAY
AFTERNOON, INCREASING TO HIGH END SCA LEVELS, TO POSSIBLY LOW
END GALE CONDITIONS, ESPECIALLY FOR AMZ350 AND AMZ374. HAZARDOUS
CONDITIONS, ESPECIALLY FOR SEAS, ARE EXPECTED TO REMAIN THROUGH
LATER MONDAY, ESPECIALLY BEYOND 20 NM OFFSHORE. WINDS AND SEAS
ARE EXPECTED TO FALL BELOW ANY HIGHLIGHT LEVELS TUESDAY THROUGH
WEDNESDAY.
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...DPB
SHORT TERM...RFM
LONG TERM...RFM
AVIATION...DPB/RFM
MARINE...DPB/RFM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page