FXUS62 KCHS 271751 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 1251 PM EST Sat Dec 27 2025
.SYNOPSIS...
High pressure will prevail through this weekend. A cold front will move through the area Monday bringing below normal temperatures to the area Tuesday and Wednesday. Temperatures will then trend warmer through the remainder of the work week.
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.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, a broad ridge with an axis extending across the Deep South and a trough positioned just off the Northeast Coast will favor a west-northwest downslope flow across the Southeast United States. At the sfc, a west-northwest sfc wind will prevail along the northern periphery of high pressure centered across Florida and well ahead of a cold front advancing south across the Mid-Atlantic States, setting the stage for near record high temps locally as the dry downslope wind erodes clouds and the bulk of the area experiences a full day of sun. Latest 1000-850 mb thickness values support high temps in the mid-upper 70s (warmest away from the coast). A few spots could even touch 80 degrees. Please see climate section below for record high temperature information.
Tonight: Aloft, broad ridging across the Deep South will gradually nudge east, placing a ridge axis directly over the Southeast. At the sfc, high pressure remains centered across Florida while a cold front advances south across the Carolinas and eventually stalls near the South Carolina/Georgia state line overnight. The front is expected to remain dry, but there continues to be some fog concerns during the second half of the night. Guidance remains mixed in regards to fog potential and visibility reduction locally, but the weather pattern suggests fog along and south of the stalled front across Southeast Georgia, with greatest fog potential near the Altamaha River (about 25% probability of 1/4 mile or less visibility in this area) late night. North of the front, slightly drier air could filter into the area and the 1000 mb geostrophic wind remains in the 10-15 kt range, limiting stratus build down and/or fog potential/coverage. Clouds could also play a significant role in fog potential south, but sfc winds are light and sfc dewpts remain in the lower 60s, suggesting at least a shallow ground fog setup as temps dip into the mid-upper 50s late night.
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.SHORT TERM /SUNDAY THROUGH TUESDAY/...
Sunday: Surface high pressure will be anchored across Virginia with the ridge axis extending from central North Carolina northeast towards New Jersey. A weak back door cold front will also likely be stalled around the TriCounty. Low level thermal profiles do cool off a bit as 850/ 925mb layer flow backs from the southwest bringing an end to the downslope flow. As such, high temperatures will be 5 to 10 degrees cooler Sunday compared to Saturday (or in the lower to mid 70s). No precipitation is expected.
Monday: A strong cold front will approach the area from the northwest as a potent 500mb wave moves east across the Great Lakes region (over 300m height falls). The cold front is expected to cross the region in the late morning to early afternoon hours and usher in much cooler and drier air. Before the cold front arrives, low level thermal profiles will respond to the compressional warming out ahead of the front and allow temperatures to reach the low 70s once again. Right behind the cold front, strong cold air advection (CAA) will commence and with steepening lapse rates wind gusts of 25 to 30 mph will be possible. A lake wind advisory will likely be needed. Temperatures will rapidly fall into the 30s Monday night with lows Tuesday morning likely right around freezing for most areas (mid to upper 30s at area beaches). Winds will be diminishing late Monday night, so minimum apparent temperatures are forecast to be in the low to mid 20s, or short of Cold Weather Advisory criteria. The latest run of the LREF is advertising around a 20% chance of apparent temperatures reaching Cold Weather Advisory criteria (20 degrees F) in our inland Georgia zones and less than 5% elsewhere.
Tuesday: High pressure will surge south to Texas Tuesday morning with 850mb temperatures continuing to tick down towards 3 - 5 degrees C over South Carolina and Georgia. High temperatures Tuesday will only be around 50 degrees. Overnight lows will be in the lower to mid 20s, with winds decreasing. Area wide, there is around a 20% chance of apparent temperatures reaching Cold Weather Advisory criteria.
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.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Surface high pressure will be located across southeast Texas Wednesday and start to breakdown as another mid-level wave dives southeast out of Canada. Ensemble guidance is in fairly good agreement in the long term, with WPC Cluster Analysis showing a rather dispersive set of model solutions. General consensus is for a warming trend to start on Wednesday and then persist into next weekend. This makes sense as the long wave trough axis that brought the below normal temperatures on Tuesday and Wednesday slowly moves east. No precipitation is forecast through the long term with abnormally dry (or worse) conditions persisting through much of the area.
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.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR conditions will prevail at CHS/JZI/SAV terminals through this evening. A dry front will then enter from the north, turning west- northwest winds more east-northeast overnight. The potential for fog increases during the second half of the night, with the best chance for visibilities lowering at the SAV terminal a few hours prior to daybreak. However, confidence remains lower due to clouds expanding across the area overnight. For now, all terminals remain VFR through 18Z Sunday, but future TAF issuances could need to include flight restrictions due to fog in the 08Z-13Z Sunday timeframe (mainly at SAV).
Extended Aviation Outlook: Sunday: Surface high pressure will be centered across North Carolina, Virginia, and New Jersey allowing for easterly winds over the terminals. Fog from Sunday morning will dissipate with morning restrictions quickly turning VFR. East winds veering from the southeast less than 10 kt.
Monday: Southwest winds ahead of an approaching cold front. FROPA will then occur at the terminals early Monday afternoon with winds turning from the west/ northwest with wind gusts 20 to 30 kt. VFR.
Tuesday and Wednesday: VFR with winds from the west/ northwest around 10 to 15 kt.
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.MARINE...
Today and Tonight: High pressure will remain centered across Florida while a weak cold front approaches from the north today, reaches local waters this evening, then stalls in the vicinity overnight. Southwest winds up to 10-15 kt will be common ahead of the front today along with seas in the 2-4 ft range (largest across offshore Georgia waters). Sfc winds are expected to turn east-northeasterly in wake of the front overnight with perhaps an uptick in wind gusts as well, but should generally remain around 15 kt or less through the overnight period. Seas should subside about 1 ft overnight, ranging between 1-3 ft during the second half of the night (largest across offshore Georgia waters).
Sunday: Surface high pressure will move east off of the Mid-Atlantic coast with southerly winds less than 10 kt over the waters. Seas 1 to 3 ft.
Monday: A strong cold front will cross the waters Monday afternoon with winds turning from the northwest sustained 15 to 20 kt and gusts 25 to 30 kt. Seas will also respond accordingly and rise 4 to 7 ft. Small Craft Advisories will likely be needed for all waters (the potential exception being Charleston Harbor) Monday afternoon into evening.
Tuesday: Northwest winds will start to diminish as the pressure gradient weakens with Small Craft Advisories likely coming to an end by early Tuesday morning. Seas 4 to 7 ft relaxing to 2 to 4 ft by late afternoon.
Wednesday and Thursday: Winds out of the west as surface high pressure centers over the northwestern Gulf. Seas 2 to 4 ft.
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.CLIMATE...
Record High Temperatures:
December 27: KCHS: 78/2021 KCXM: 76/2015 KSAV: 80/2015
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...None. MARINE...None.
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NEAR TERM...DPB SHORT TERM...Haines LONG TERM...Haines AVIATION...DPB/Haines MARINE...DPB/Haines