220
FXUS62 KCHS 121124
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
624 AM 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/
TODAY: ALOFT, ZONAL FLOW WILL PREVAIL ACROSS THE FORECAST AREA
WITHIN A BROADLY CYCLONIC FLOW REGIME. AT THE SURFACE, HIGH
PRESSURE WILL BE SITUATED SOUTH AND SOUTHEAST OF THE AREA WITH A
BOUNDARY DRAPED WEST TO EAST ACROSS NC BACK THROUGH THE LOWER
MS VALLEY. MODEST SOUTHWESTERLY FLOW ACROSS THE AREA WILL HELP
YIELD A PLEASANT DAY WITH MOSTLY CLEAR SKIES. HIGHS ARE FORECAST
TO PEAK AROUND OR JUST OVER 60 ACROSS SOUTHEAST SC, AND THE LOW
TO MID 60S ACROSS SOUTHEAST GA.
TONIGHT: QUIET CONDITIONS WILL CONTINUE. EXPECT MOSTLY CLEAR
SKIES AND LIKELY JUST ENOUGH LIGHT SOUTHWESTERLY FLOW TO PREVENT
IDEAL RADIATIONAL COOLING CONDITIONS. WE SHOULD STILL SEE SOME
UPPER 30S INLAND RANGING TO 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.
HOWEVER, FOR SATURDAY, CONDITIONS WILL BE MORE PLEASANT BEFORE
THE ARCTIC FRONT, WITH ZONAL UPPER LEVEL FLOW AND LOW LEVEL
SOUTHWEST WINDS. EXPECT HIGHS ON SATURDAY TO WARM TO ABOVE
NORMAL IN THE MID 60S TO NEAR 70. THESE TEMPERATURES WILL BE
WARMER THAN WE HAVE BEEN SO FAR THIS MONTH OF DECEMBER BY ABOUT
5 TO 10 DEGREES! A MILD NIGHT SATURDAY NIGHT AS A DEEP UPPER
TROUGH TAKES SHAPE OVER THE GREAT LAKES AND INTO THE MID
ATLANTIC. WITH SOUTHWEST LOW LEVEL FLOW, LOWS WILL STAY IN THE
UPPER 40S INLAND TO THE LOWER TO MID 50S CLOSER TO THE COAST.
BY SUNDAY, THE UPPER TROUGH CONTINUES TO SHARPEN AND MOVE
EASTWARD, WHICH WILL HELP TO DRIVE AN ARCTIC FRONT THROUGH THE
REGION. MODELS CONTINUE TO HAVE DIFFERENCES IN TIMING WITH THE
FRONT, BUT BLENDED SOLUTIONS POINT TOWARD LATE MORNING TO EARLY
AFTERNOON FOR IT TO PASS THROUGH THE REGION. ONLY MARGINAL
MOISTURE WILL BE PRESENT WITH THE FRONT. SO, OTHER THAN SOME
ISOLATED SHOWERS, NOT EXPECTING AND SIGNIFICANT 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 REMINDER OF THE
AFTERNOON. A STRONG SURFACE RIDGE WILL BUILD FROM THE NORTHWEST
THROUGH SUNDAY NIGHT, PRODUCING BRISK NORTHWEST TO NORTH WINDS,
DRIVING ARCTIC TEMPERATURES SOUTHWARD THROUGH THE REGION. LOWS
SUNDAY NIGHT LIKELY RANGING FROM THE UPPER TEENS INLAND TO THE
LOWER TO MID 20S CLOSER TO THE COAST. A COLD WEATHER ADVISORY IS
LOOKING LIKELY FOR SUNDAY NIGHT. THESE TYPE OF COLD
TEMPERATURES WILL BE VERY HAZARDOUS, AND COULD CAUSE ISSUES WITH
EXPOSED PIPES/PLUMBING.
MONDAY, THE SURFACE RIDGE MOVES OVER THE REGION WITH LIGHTER
NORTH- NORTHEAST WINDS. EVEN WITH SUNNY SKIES, HIGHS EXPECTED TO
ONLY REACH 40 TO 45, WHICH WOULD BE AT LEAST 15 DEGREES BELOW
NORMAL!
LONG TERM /MONDAY NIGHT THROUGH THURSDAY/
MONDAY NIGHT WILL START OFF VERY COLD AS THE SURFACE RIDGE SITS
OVER THE REGION WITH LIGHT WINDS AND CLEAR/MOSTLY CLEAR SKIES.
LOWS AROUND 20 TO THE LOWER 20S WELL INLAND, AND MID TO UPPER
20S CLOSER TO THE COAST. WITH LIGHTER WINDS AND SLIGHTLY HIGHER
SURFACE DEWPOINT TEMPERATURES POSSIBLE, PATCHY TO SCATTERED
FROST CANNOT BE RULED OUT.
TUESDAY THROUGH FRIDAY, MODELS INDICATE A PATTERN CHANGE WITH
GENERALLY ZONAL UPPER FLOW AND TEMPERATURES MODERATING. HIGH
TEMPERATURES POSSIBLY BACK NEAR NORMAL BY WEDNESDAY, AND EVEN
ABOVE NORMAL THURSDAY AND FRIDAY WITH HIGHS WELL INTO THE 60S TO
NEAR 70. THERE ARE MODEL DIFFERENCES WITH PRECIP. CHANCES LATER
IN THE WEEK WITH THE POTENTIAL FOR SOME UPPER TROUGHING AND
COASTAL TROUGH. BLENDED SOLUTIONS AND CURRENT FORECAST KEEP
SLIGHT CHANCE POPS FOR SHOWERS THURSDAY, BUT CONFIDENCE IS LOW
AT THIS TIME.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
VFR CONDITIONS WILL PREVAIL AT KCHS, KJZI, AND KSAV THROUGH 12Z
SATURDAY.
EXTENDED AVIATION OUTLOOK: GUSTY WINDS ARE EXPECTED SUNDAY INTO
MONDAY MORNING BEHIND A STRONG ARCTIC COLD FRONT. OTHERWISE,
VFR CONDITIONS EXPECTED SATURDAY THROUGH EARLY NEXT WEEK.
MARINE
TODAY THROUGH TONIGHT: WINDS ACROSS THE LOCAL WATERS WILL TURN
SOUTHWESTERLY AND INCREASE INTO THE 10-15 KNOT RANGE THROUGH THE
AFTERNOON. THIS SOUTHWEST FLOW REGIME WITH SPEEDS AROUND 10-15
KNOTS SHOULD CONTINUE THROUGH THE OVERNIGHT AS WELL. SEAS ARE
FORECAST TO AVERAGE 2 FEET TODAY, THEN 2-3 FEET OVERNIGHT.
NO HIGHLIGHTS EXPECTED THROUGH SATURDAY NIGHT WITH A RIDGE OF
HIGH PRESSURE CENTERED EAST-SOUTHEAST OF THE WATERS AND
SOUTHWEST WINDS OF 10 TO 20 KNOTS AND SEAS GENERALLY 2 TO 3
FEET.
BY SUNDAY, AN ARCTIC FRONT IS EXPECTED TO PUSH THROUGH THE
WATERS, LIKELY PASSING EAST OF THE WATERS BY LATE
AFTERNOON/EARLY EVENING. WINDS ARE EXPECTED TO INCREASE
DRAMATICALLY BEHIND THE FRONT, WITH HIGH END SCA CONDITIONS
LIKELY BY LATE AFTERNOON/EARLY EVENING. THERE IS A POSSIBILITY
FOR LOW END GALE CONIDITONS, ESPECIALLY FOR AMZ350 AND AMZ374.
HIGH END SCA TO POSSIBLY LOW END GALE CONDITIONS ARE LIKELY TO
PERSIST INTO MONDAY NIGHT, ESPECIALLY FOR SEAS OF 6 FEET OR
GREATER BEYOND 20 NM OFFSHORE.
TUESDAY, WINDS AND SEAS ARE EXPECTED TO FALL BACK BELOW ANY
HIGHLIGHT 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...NONE.
SC...NONE.
MARINE...NONE.
NEAR TERM...BSH
SHORT TERM...RFM
LONG TERM...RFM
AVIATION...BSH/RFM
MARINE...BSH/RFM
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