Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
547 FXUS62 KCHS 260519 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1219 AM EST Wed Nov 26 2025 .SYNOPSIS... A strong cold front will sweep through late today, with high pressure building into the region Thursday and into the weekend. && .NEAR TERM /THROUGH TONIGHT/... An area of dense fog has developed over parts of the Charleston Tri-County early this morning. Vsbys in parts of the Charleston Metro area have been below 1/4 mile at times per regional webcams and surface observations. The fog is expected to lift as wind fields aloft increase as the pre-frontal low-level jet nudges in from the west and boundary layer mixing strengthens. The fog could be gone by 2 AM, if not sooner. It does not appear as though a Dense Fog Advisory is needed, but trends are being monitored. A cold front is on target to push from west-east across the South Carolina Lowcountry and Southeast Georgia today, reaching far interior Southeast Georgia by mid-morning, the I-95 corridor by late morning and finally clearing the upper Charleston County coast by mid-afternoon. Radar composites show a pretty healthy area of showers/tstms with the front, being mostly driven by forcing associated with the right entrance region of 100-110 kt jet that is strengthening along the southern flanks of a powerful upper low that is pivoting across the Upper Mississippi Valley. This corridor of upper forcing is expected to steadily weaken with time as the jet streak gradually lifts out to northeast while net moisture values and mean 850 hPa theta-e both lower with time as drier air begins overtake the frontal surface from the west. This will likely result in a steadily weakening of convection along/head of the front through the morning hours. How much convection survives prior to the front pushing offshore is still a bit uncertain, but most guidance support a broken line of showers moving into the western zones later this morning and steadily weakening as it approaches the coast. Average QPF will range from a trace to 0.10", highest across interior Southeast Georgia. Pops today range from 20-30% along/west of I-95 with 10-20% between I-95 and the beaches. Highs will warm into the mid-upper 70s except upper 60s/lower 70s with southwest winds becoming a bit breezy later this morning and continuing until FROPA. Gusts could reach as high as 25-30 mph at times. Cooler and drier conditions will prevail tonight as secondary surge pushes through this evening and high pressure builds in from the west and northwest. Lows Thanksgiving morning will range from the upper 30s/lower 40s well inland to the upper 40s/near 50 at the beaches. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... A longwave trough aloft will dominate over the southeastern states on Thursday before shifting off the East Coast into Friday, yielding zonal flow into the weekend. At the surface high pressure will build into the region from the west behind the departing cold front. This high pressure will prevail into the weekend, resulting in a dry forecast. The main forecast highlight into the weekend will be the noticeably cooler temperatures. Highs on Thursday will reach to around 60, with Friday and Saturday struggling to get out of the 50s across most locations. Overnight lows will similarly be cooler, with freezing temperatures likely along and west of I-95 both Thursday and Friday nights. Upper 30s/low 40s are expected along the coastal counties. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... Zonal flow will dominate aloft through the remainder of the weekend, with high pressure prevailing at the surface. This pattern will yield a cool and dry forecast, with no rain chances and below normal temperatures forecast. There are indications that a coastal low could develop just off of the southeastern coast early next week. However, there is much uncertainty with this system, as cluster analyses are not showing good agreement between models. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... 26/06z TAF Discussion: KCHS/KJZI/KSAV: Dense fog at KCHS should lift shortly as low- level jetting builds and mixing commences. Marginal low-level wind shear (LLWS) is possible at all three terminals, but data suggest the degree of shear below 2kft will remain just shy of mentionable thresholds. VFR will otherwise prevail at all three terminals through 27/06z. A cold front will reach the terminals by early afternoon with winds shifting to the west. Prior to FROPA, wind gusts could reach as high as 20-25 kt beginning mid- morning. The risk for isolated shower activity with the front reaching the terminals is low, so no mention was included for the 06z TAF cycle. Extended Aviation Outlook: Prevailing VFR. && .MARINE... Through Tonight: Southwest winds will increase ahead of an approaching cold front today. The front will reach the waters by mid-afternoon and should push east by late afternoon. A reinforcing surge will push offshore tonight, resulting in a secondary wind surge to the northwest. Both surges should max out no higher than 15 kt to perhaps 15-20 kt with gusts generally holding less than 25 kt. Right now, it looks like winds will not reach Small Craft Advisory levels, although it could get close at times. Seas will peak 2-4 ft, except 3-5 ft over the South Santee-Edisto Beach nearshore leg this afternoon with 2-4 ft prevailing all waters overnight in the offshore flow. Thursday through Saturday: High pressure will build into the region on Thursday behind a departing cold front. Post-FROPA will see shift to the NE, with winds around 15 knots with gusts to 20 knots. Some gusts on Thursday night could approach 25 knots, especially over the 20 to 60 nm offshore GA waters. However, the duration of time of these conditions is too short to warrant a Small Craft Advisory. Seas are forecast to average 2 to 3 ft with some 4 ft seas in the 20 to 60 nm offshore GA waters. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$