FXUS62 KCHS 231753 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 1253 PM EST Tue Dec 23 2025
.SYNOPSIS...
High pressure will prevail through the holiday week. A cold front could move through the area Sunday night or early Monday.
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.NEAR TERM /THROUGH TONIGHT/...
The Charleston Doppler (KCLX) radar has detected a band of light returns moving east across portions of inland SC Lowcountry. Sfc based observations have indicated some sprinkle activity with the greater reflectivity. The forecast will mention sprinkles across the inland SC Lowcountry through early this afternoon.
Tonight, the sfc pattern will feature high pressure centered over the Deep South as a trough remains over the east facing slopes of the southern Appalachians. This pattern should support light west winds across the forecast during the overnight hours. A backdoor cold front will push slow southward across NC late tonight, but will remain north of the forecast area. Low temperatures are forecast to range around 50 degrees.
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.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Overview: Warm conditions with above normal temperatures expected through the period.
An anomalously strong mid and upper level ridge is expected to remain west of the region through the period. At the surface, a ridge of high pressure will be off the Mid Atlantic coast on Wednesday, then shifting eastward on Thursday as a weak upper level disturbance moves well north of the region. This upper level feature seems to drag a weak surface front toward the area later Thursday and into Friday, likely stalling and weakening over the northern part of the area. There is some moisture return with this weak front, but given a lack of upper level support, no significant precipitation chances are expected.
Temperatures will be the main story for this period. Highs each day generally in the 70s, warmest over our GA zones. Lows mostly in the 50s. These values are 10 to 15 degrees above seasonal normal values.
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.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Through Sunday: The strong mid and upper level ridge seems to hang on west and southwest of the area, including much of the southern U.S. states. This will maintain above normal temperatures through this period, with highs in the 70s and lows mainly in the 50s. Again, these values are 10-15 degrees above normal levels.
Sunday night and Monday: Global models and blended solutions point toward a potential pattern shift back to colder conditions as a deep upper level trough develops over south central Canada, and then extending into the eastern U.S. region. An arctic surface front may approach the region from the northwest Sunday night, then possibly sweep through the entire region Monday. Current indications are that this front will be pretty dry as it moves through. Cooler temperatures expected for Monday, with highs in the lower 60s, which are closer to normal. We will be monitoring the forecast for the potential for very cold/subfreezing conditions again just beyond the period Monday night and Tuesday.
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.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
18Z TAFs: VFR. Winds should remain from the west between 5 to 10 kts tonight, turning from the northwest after sunrise Wednesday morning.
Wednesday through Sunday: VFR conditions are expected to prevail.
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.MARINE...
Tonight, winds will remain from the west around 10 kts within 20 NM, 10 to 15 kts beyond 20 NM. By late tonight, seas should subside to 2 to 4 ft.
No highlights are expected through Sunday. Winds generally 15 knots or less and seas 2 to 4 feet, highest beyond 20 nm offshore. Winds may increase back into SCA levels ahead of an arctic front later Sunday. Just beyond the forecast we will continue to watch for the potential for an arctic cold front to move across the waters Sunday night and into Monday, which could bring back the threat for solid SCA conditions.
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...None. MARINE...None.
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NEAR TERM...NED SHORT TERM...RFM LONG TERM...RFM AVIATION...NED/RFM MARINE...NED/RFM