Mount Pleasant, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

765
FXUS62 KCHS 230148
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
848 PM EST Mon Dec 22 2025

.SYNOPSIS...
High pressure will prevail through the holiday week.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A wedge of high pressure will maintain its influence on the
region tonight. Winds at buoy 41008 have been showing signs of
backing with time suggesting the genesis of a weak coastal
trough is ongoing. Indeed, weak isentropic ascent rooted along
the 290-300K surfaces is aiding in the production of a 5000 ft
ceiling along parts of the Georgia coast which has been slowly
growing in size since sunset. These clouds are expected to
steadily expand inland and to the north through the night as the
coastal trough sharpens offshore. While no rainfall is expected
over land, the thickening cloud cover will likely have a
warming influence on overnight temperatures, especially along
the Georgia and far southern South Carolina coast. Temperatures
in these areas may only fall another few degrees before leveling
out and possibly even rising slightly during the early morning
hours. Farther inland, the boundary layer is quickly decoupling
with mainly clear skies. This is promoting strong radiational
cooling conditions with some spots over the Francis Marion
National Forest already reporting temperatures in the upper
30s/lower 40s as of 23/0130z. Pinning down lows will be a
challenge as radiational processes will weaken with time as
clouds thicken from the south. Updated low favor upper
30s/lower 40s across northern parts of Dorchester, Berkeley and
upper interior Charleston County (some mid 30s in the spots over
the Francis Marion National Forest) with mid-upper 40s
elsewhere except lower-mid 50s at the beaches.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
Tuesday through Christmas: Short term guidance indicates that a
strong H5 ridge will remain centered over the Gulf, with the
ridge axis extending across the central CONUS. During the
period, an amplified wave will ripple across New England,
pushing over the north Atlantic on Christmas Eve. This pattern
will keep the forecast area under dry NW flow aloft. At the sfc,
high pressure should remain centered over the northern Gulf
coast, with a possible dry cold front late Christmas. Overall,
the forecast will feature dry and very mild conditions through
the short term period. Temperature should trend warmer through
Christmas, with Christmas temperatures featuring lows around 50
and highs in the mid to upper 70s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Very mild and dry weather will continue across the forecast
area through this weekend. The H5 pattern will continue to
feature a shallow longwave ridge across the southern CONUS. High
pressure will remain across the Southeast U.S. through Saturday
night. By Sunday, a cold front will approach from the west,
return flow will keep temperatures in the mid to upper 70s. The
cold front is timed to pass over the region Sunday evening and
night. Isolated rain showers gusty NW winds should accompany the
passage of the front. Temperatures may cool by 15 degrees by
Monday, with highs near 60 degrees.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
23/00z TAF Discussion:
KCHS/KJZI/KSAV: VFR through 24/00z.

Extended Aviation Outlook: A brief period of MVFR cigs/vsbys
will be possible Wednesday morning due to fog or stratus
development. Otherwise, expect VFR conditions to prevail.

&&

.MARINE...
Tonight: Winds are finally showing some signs of diminishing,
but still remain solidly northeast. Speeds near 20 kt with gusts
to 25 kt will persist for a few more hours. Seas remain above 6
ft as well per buoy observations, but both winds and seas should
drop below advisory thresholds across the nearshore waters by
midnight or 1 AM. Seas will remain above 6 ft over the Georgia
offshore waters through the night.

Tuesday: Small Craft Advisory will continue across the offshore
Georgia waters through Tuesday afternoon due to lingering 6 ft
seas. Marine conditions then improve Tuesday evening, with
southwesterly winds around 10 kts and seas dropping to 4 ft.

Wednesday Through Saturday: High confidence in no marine
headlines. The pattern will support winds around 10 kts and seas
between 2 to 4 ft.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 1 AM EST Tuesday for AMZ350-352-354.
     Small Craft Advisory until 6 PM EST Tuesday for AMZ374.

&&

$$

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