FXUS62 KCHS 311816 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 116 PM EST Wed Dec 31 2025
.SYNOPSIS...
High pressure will prevail through Friday. A low pressure system will move through on Saturday, followed by more high pressure next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Visible satellite shows a few patches of cirrus drifting across the southern Appalachians this afternoon. HREF simulated satellite indicates that some thin cirrus may reach the SC Lowcountry this evening, then clear conditions the rest of the night. At the sfc, the forecast area will remain between high pressure over FL as a trough remains centered along the Carolina escarpment. This pattern should yield steady west winds around 5 mph overnight. Given cool llvl thicknesses, light winds, and clear sky should result in below normal temperatures tonight. Using a blend of guidance, low temperatures are forecast to range around freeze along and west of I- 95 to the mid to upper 30s to the east.
Lake Winds: Soundings support frequent gusts around 25 kt with sustained winds closer to 15-20 kt. A Lake Wind Advisory has been posted 10 PM to 10 AM Thursday per coordination with WFO Columbia. Waves are expected to peak around 2 ft with the highest winds and the most significant wave action occurring over the central and eastern parts of the lake.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
Thursday: Northwesterly flow will prevail in the mid-levels. At the surface, High pressure will prevail. While dry conditions should prevail, there could be a brief surge of westerly winds in the morning, that should ease into the afternoon. High temperatures will be near normal, generally around 60 degrees. At night, radiational cooling will cause temperatures to drop back into the mid 30s inland and up to the lower/mid 40s along the coast.
Friday: Zonal flow will prevail in the mid-levels while High pressure prevails to our southeast. There will be a warm front located to our north with a system approaching from the distant west. This will cause clouds to increase during the day. Highs will still be in the lower to mid 60s. Overnight, POPs trend higher, especially further inland. But the QPF will be highly dependent on the arrival timing, especially far inland. Regardless, lows will be mild, in the mid 40s to lower 50s.
Saturday: Weak shortwaves will move over our area. Meanwhile, a low pressure system will also move over our area. Moisture will increase ahead of this system. Likewise, we're expecting widespread light to moderate rain showers. The exact QPF is still somewhat uncertain a few days out. But it doesn't appear to be enough to cause major flooding concerns and it probably won't be enough to put a large dent in the ongoing drought. Despite the rain, temperatures will be in the lower to upper 60s.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Mid-level northwesterly flow moves overhead while the storm system moves out. High pressure should then prevail through the middle of next week. High temperatures will start off a tick below normal Sunday and Monday, then creep back above normal Tuesday and Wednesday.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
18Z TAFs: VFR. West winds may develop gusts above 15 kts Thursday morning.
Extended Aviation Outlook: A low pressure system will bring increased probabilities of flight restrictions on Saturday.
&&
.MARINE...
Tonight, the marine zones will remain between high pressure ridged across FL and a sfc trough centered over the escarpment of the Carolinas. This pattern should yield a 4-5 mb pressure gradient across the Atlantic waters. West winds are forecast to strengthen this evening, with gusts between 25 to 30 kts. The GA nearshore waters may approach 25 kts during the pre-dawn hours, but should generally remain in the low 20s overnight. In addition, wave heights should gradually build overnight, reaching 3-5 ft by late tonight. Small Craft Advisories have been issued for the CHS Harbor, nearshore SC and outer GA waters from 11 PM until 10 AM Thursday.
Thursday and Friday: Winds and seas will be trending lower early Thursday morning, so any remaining Small Craft Advisories are expected to expire. High pressure will then prevail, bringing modest winds and seas later Thursday into Friday.
Saturday and Sunday: A low pressure system will impact the coastal waters on Saturday, then move away on Sunday. At this time, the highest probabilities for Small Craft Criteria being met are for the GA waters beyond 20 nm. But based on the pattern, we wouldn't be surprised if Advisories are needed for all of the waters. This will be highly dependent on the strength and track of the system.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...Lake Wind Advisory from 10 PM this evening to 10 AM EST
Thursday for SCZ045.
MARINE...Small Craft Advisory from 11 PM this evening to 10 AM EST
Thursday for AMZ330-350-352-374.
&&
$$
NEAR TERM...NED SHORT TERM... LONG TERM... AVIATION...NED MARINE...NED