FXUS62 KCHS 110535 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 1235 AM EST Thu Dec 11 2025
.SYNOPSIS...
High pressure will prevail through Saturday, then an arctic cold front will sweep through late Sunday. Dry high pressure will then rebuild.
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.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, a deep trough associated with an impressive upper low on the eastern periphery of the Great Lakes will swing through the Southeast. At the surface, cold high pressure will build into the region behind the long departed cold front well offshore. Overall, a very quiet and chilly day. After some cirrus passes through in the morning, clear skies will prevail through the rest of the day. Expect northwest winds through the morning, gradually turning more westerly through sunset. Temperatures will certainly be on the chilly side, with low 50s for southeast SC and low to mid 50s for southeast GA. Such values would be on the order of 10 degrees below normal.
Tonight: With high pressure across the area and clear skies, good radiational cooling conditions will be in place across the forecast area. Lows are forecast to fall below freezing away from the coastal corridor, with a few of the typical cold spots dipping into the upper 20s. Along the coast, mid to upper 30s will be common.
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.SHORT TERM /FRIDAY THROUGH SUNDAY/...
A zonal flow will exist Friday into Saturday while the surface high moves off the Southeast coast. Dry weather and warming temperatures expected.
An arctic cold front will approach from the northwest Saturday night, then sweep through Sunday afternoon or evening. Moisture and forcing will be weak but isolated rain showers could accompany the frontal passage on Sunday. Temperatures will rapidly drop Sunday evening behind the front.
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.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Strong cold advection behind the front will bring chilly temperatures Monday morning, along with nippy wind chills. Lows will dip into the low to mid 20s away from the coast while wind chills late Sunday night will range from 10-15 degrees for several hours. A Cold Weather Advisory looks increasingly likely for much of the area.
Monday will remain chilly with highs only in the lower 40s and wind chills in the 30s. Another chilly night expected Monday night, but this time due to calm winds, clear skies, and strong radiational cooling.
A warming trend will occur heading into the middle of next week as the arctic high shifts offshore.
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.AVIATION /06Z THURSDAY THROUGH MONDAY/...
VFR conditions will prevail at KCHS, KJZI, and KSAV through 06z Friday. Winds could get a bit breezy through sunrise as a cold front passes through.
Extended Aviation Outlook: VFR.
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.MARINE...
Through sunrise: The peak winds are likely still to come as the cold front is still just upstream of the forecast area. Frequent wind gusts into the 25-30 knot range are expected across the waters, including Charleston Harbor. There is still a short window of time when a few gale force gusts are possible in the Charleston County waters and the outer GA waters, but we still expect high end Small Craft Advisory conditions to prevail.
Today through tonight: Winds and seas will both continue to diminish this morning such that all Small Craft Advisories will come down by late morning. Through the rest of the day, expect northwest winds mostly in the 10-15 knot range. Overnight, wind speeds will remain similar while wind direction becomes more westerly. Seas will steadily decrease through the day and will then be mostly 2-3 feet overnight.
Sunday afternoon through Monday will be quite windy over the waters as strong high pressure builds in behind an arctic cold front. At a minimum, solid Small Craft Advisory conditions are anticipated for all waters. A period of Gale force gusts is increasingly likely for Sunday night, particularly the Charleston nearshore and GA offshore waters.
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...Lake Wind Advisory until 5 AM EST early this morning for
SCZ045.
MARINE...Small Craft Advisory until 5 AM EST early this morning for
AMZ330-354. Small Craft Advisory until 7 AM EST this morning for AMZ350- 352. Small Craft Advisory until noon EST today for AMZ374.
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NEAR TERM...BSH SHORT TERM...JRL LONG TERM...JRL AVIATION...BSH/JRL MARINE...BSH/JRL