FXUS62 KCHS 232321 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 621 PM EST Fri Jan 23 2026
.WHAT HAS CHANGED...
The aviation section has been updated for the 14/00z TAFs. Small Craft Advisory has been issued for Charleston Harbor for Saturday.
&&
.KEY MESSAGES...
- 1) Widespread precipitation is expected Saturday through Sunday night, with freezing rain possible Saturday night into Sunday morning across inland portions of the SC Lowcountry and SE GA.
- 2) Very cold temperatures will occur early next week, with
lows in the upper teens to lower 20s away from the coastline.
&&
.DISCUSSION...
KEY MESSAGE 1: Widespread precipitation is expected Saturday through Sunday night, with freezing rain possible Saturday night into Sunday morning across inland portions of the SC Lowcountry and SE GA.
The period of winter weather begins late Saturday as the center of a Arctic air mass reaches New England. This dry and cold air mass should ridge southwest across the Southeast U.S late Saturday, with cold air damming strengthening through the night. Given the approach of a broad H5 trough and upper divergence associated with a 190 kt jet over the Mid-Atlantic/New England, a low is forecast to develop off the GA/SC coast. As the low develops, deep isentropic lift will develop over the wedged high pressure, producing widespread light precipitation. Gusty northeast winds and wet-bulb effects should result in temperatures to cool into the 30s across inland SC Lowcountry into SE GA. By late Saturday night, sfc temperatures are forecast to drop to around 30 degrees from Berkeley County west to Jenkins County. Precipitation may transition from a cold rain, to a mix of rain and freezing rain, then as freezing rain. Ice accumulations up to a tenth of an inch are possible, especially on elevated surfaces across northern Dorchester, Allendale, and Berkeley counties by Sunday morning. Some high resolution guidance surges sub-freezing southward across the Lowcountry and deep into SE GA. If this occurs, it appears that brief freezing rain or drizzle could occur closer to the coast before daybreak Sunday. This could lead to slick surface either by freezing precip or freezing surface moisture from earlier rainfall.
On Sunday, the coastal low should continue to track northeast off the Carolina coast. Sfc winds may turn from the north, strengthening the cold air damming across the region will continue. High temperatures on Sunday were cooled significantly, limiting values to the low 50s across the inland tier of counties, elsewhere temperatures in the mid 50s or low 60s are possible. The warming temperatures on Sunday should end freezing rainfall by mid-day. A Winter Weather Advisory has been issued for a tier of counties from Jenkins County east to Berkeley Counties from 7 PM Saturday until 1 PM Sunday.
A strong cold front will approach Sunday evening, resulting in the entire area in the warm sector. A solid rain band will accompany the front, with areal average QPF at least 0.5". There could be enough elevated instability to support isolated thunderstorms Sunday evening. Colder air will follow the front, but the precip should be off the coast Monday morning and thermal profiles only support rain.
KEY MESSAGE 2: Very cold temperatures will occur early next week, with lows in the upper teens to lower 20s away from the coastline.
Arctic air is forecast to spread across the region Monday night into Tuesday morning. Using a blend of guidance, min temperatures are forecast to range in the teens west of I-95 with low to mid 20s along the coast. North to northwest winds may remain across the region, possibly around 10 mph. The combination of cold temperatures and wind may result in widespread wind chill values in the teens. In fact, min wind chills could range around 10 degrees across portions of inland GA Tuesday morning. A Cold Weather Advisory should eventually be needed for the entire area across Southeast South Carolina and Southeast Georgia.
The cold air mass will remain across the region into Wednesday morning. Low temperatures in the low to mid 20s should be common across the region by sunrise Wednesday. Winds are forecast to become lighter, favoring values around 5 mph. Min wind chill values may range from the upper teens to around 20 degrees. A Cold Weather Advisory could eventually be needed for areas inland Tuesday night into early Wednesday.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
24/00z TAF Discussion: KCHS/KJZI/KSAV: VFR conditions will give way to decreasing ceilings and increasing wind overnight as the wedge front pushes through and cold air damming begins to establish itself across the region. MVFR cigs should reach KCHS and KJZI around daybreak and KSAV by mid-morning. While IFR cigs are not currently expected, the risk for these conditions will increase after 21z, especially at KCHS and KJZI. Gusty winds with gusts in excess of 20 kt are likely at all terminals for the daytime hours.
Extended Aviation Forecast: Periods of MVFR and/or IFR conditions are likely at all terminals this weekend as a storm system develops in the Deep South and moves northward towards the region on Saturday, yielding low cigs/vsbys Sat. night into Sunday. There is a threat for freezing rain and/or freezing drizzle late Saturday night into Sunday, mainly at the CHS/JZI terminals, but highest chance remains inland. Expect a cold front to move across the region Sunday night and yield VFR conditions through early next week.
&&
.MARINE...
Through Tonight: Northeast winds are starting to increase as high pressure wedges into the region and cold air damming begins to establish itself inland. Speeds should reach 20-25 kt with gusts to 30 kt across the South Carolina nearshore waters with 15-20 kt with gusts to 25 kt across the Georgia waters. Small Craft Advisories will begin overnight. Also, given the expected pinched gradient situation, a Small Craft Advisory has been issued for the Charleston Harbor for Saturday and may need to be extended into parts of Saturday night.
Saturday through Wednesday: Strong cold air advection (CAA) combined with an enhanced pressure gradient across local waters continues to support deteriorating marine conditions on Saturday through early next week as low pressure system attempts to develop/strengthen near a cold front offshore. Northeasterly winds at 20 to 25 kt with gusts up to 30 kt possible with seas upwards of 7 to 10 ft. It's important to note that some element of wedging will attempt to spread across the region from the northwest. Therefore, Small Craft Advisories have been issued for tonight through early next week. There is a chance of low-end gale force gusts across the nearshore Charleston waters and outer Georgia waters on Saturday afternoon and night. Small Craft Advisories might be eventually needed at some point for the Charleston Harbor as well on Sat./Sat. night. These high seas should linger across most waters into Monday, while another burst of CAA takes place given post-FROPA conditions.
&&
.EQUIPMENT...
The KCLX radar will remain out of service. Critical parts are on order and repairs are scheduled to occur Saturday morning once the parts arrive. Users should use adjacent WSR-88D sites, including KCAE, KLTX, KJAX, KVAX and KJGX.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Winter Weather Advisory from 7 PM Saturday to 1 PM EST Sunday
for GAZ087-088.
SC...Winter Weather Advisory from 7 PM Saturday to 1 PM EST Sunday
for SCZ040-042>045.
MARINE...Small Craft Advisory from 7 AM to 7 PM EST Saturday for AMZ330.
Small Craft Advisory from midnight tonight to 10 AM EST Tuesday for AMZ350. Small Craft Advisory from 3 AM Saturday to 10 AM EST Tuesday for AMZ352-354. Small Craft Advisory from 3 AM Saturday to 1 PM EST Tuesday for AMZ374.
&&
$$