FXUS62 KCHS 042339 AFDCHS

Area Forecast Discussion National Weather Service Charleston SC 639 PM EST Sun Jan 4 2026

.SYNOPSIS...

High pressure will prevail across the region most of this week, bringing dry conditions and above normal temperatures. A cold front may bring showers and colder temperatures to our area next weekend.

&&

.NEAR TERM /THROUGH MONDAY/...

Tonight: Surface high pressure will move off of the Mid- Atlantic coast of the United States with a weak coastal trough forming. In the upper levels of the atmosphere, a 80 - 100 kt jet streak will transition east bringing widespread cirrus and cloud cover to the region. The main impact from the cirrus will be the slightly warmer low temperatures. However, decoupling will likely still occur with temperatures falling quickly. The two main questions are how fast will the cirrus arrive and how thick will it be. The orientation of the upper level jet streak would favor the thickest cirrus across Georgia and border regions with South Carolina. Some of the latest guidance indicates potential for fog developing, especially over the far interior areas. NBM showcases a 50-60% chance for visibility less than 5 miles in these locations, with a 20-30% chance for less than 1 mile. Opted to include patchy to areas of fog in the forecast. The threat should be lesser further east. Low temperatures are generally expected to be in the lower 40s with some upper 30s (especially across rural Berkeley County).

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...

The mid-levels will consist of west northwest flow overhead Monday morning. It'll transition to zonal flow on Tuesday, and prevail into Wednesday. At the surface, High pressure will be centered off the Mid- Atlantic Coast Monday, gradually shifting further offshore into Tuesday. At that time, High pressure will develop over the northeastern Gulf, and prevail into Wednesday. This second High will serve as a blocking feature, which will keep a passing front well north of our area on Wednesday. The only hint of showers in the land forecast is along the coast of Charleston County Monday evening, as some coastal showers try to brush against the beaches. But even then the POPs are slight chance with very minimal QPF. The overwhelming majority of land areas will be dry Monday and Monday night. Subsidence associated with the Highs will keep our entire area dry Tuesday and Wednesday. Though, we can expect a mix of sun and clouds each day. The main story will be the above normal temperatures. Highs on Monday will be in the mid to upper 60s across most of our area, except around 70 degrees south of I-16. Temperatures rise a few degrees on Tuesday, and again on Wednesday. By Wednesday we're forecasting highs in the low to mid 70s, except cooler at the beaches. Lows Monday and Tuesday night will remain very mild for this time of year.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...

Mid-level zonal flow Wednesday night will transition to ridging over the East Coast on Thursday, mainly in response to a strengthening trough over the Central U.S. The approaching trough will push the ridge offshore Friday. Then, this very strong trough will move over the East Coast Saturday into Sunday. Surface High pressure will prevail across our region into Thursday, then shift offshore on Friday. Temperatures will remain well above normal both of these day. A strong storm system with an associated front may impact our area Saturday and Sunday, bringing rain and colder temperatures.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...

Prevailing VFR is expected through much of the valid TAF cycle. There is concern that a period of flight restrictions in fog/stratus could impact KSAV overnight towards early Monday morning with NBM indicating roughly a 40-50% chance for ceilings less than 3kft and 30% for less than 1kft. Opted for VFR for now and will monitor trends.

Extended Aviation Outlook: VFR through Thursday. An approaching cold front could bring increased probabilities for flight restrictions later Friday.

&&

.MARINE...

Tonight: Northeast winds 5 to 10 kt with seas 2 to 4 ft.

Extended Marine: High pressure will be centered off the Mid-Atlantic Coast Monday, gradually shifting further offshore into Tuesday. At that time, High pressure will develop over the northeastern Gulf, and prevail into Wednesday. This second High will keep a front well north of our coastal waters. Thursday the High shifts off the Southeast coast. Even with all of these synoptic features, winds and seas will remain at levels that Small Craft Advisories are not expected.

&&

.CLIMATE...

Record High Temperatures: January 9: KSAV: 77/2008

Record High Minimum Temperatures: January 9: KCHS: 58/1946

&&

.CHS WATCHES/WARNINGS/ADVISORIES...

GA...None. SC...None. MARINE...None.

&&

$$

NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...Haines