091
FXUS62 KCHS 080012
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
712 PM EST Sun Dec 7 2025

.SYNOPSIS...
A frontal system will maintain unsettled weather into Monday,
then a cold and dry high pressure will build into the region. A
reinforcing cold front will move through Friday.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Tonight: The mid-levels will consist of a trough over the Lower MS
Valley in the evening. It`ll shift eastward, stretching from the
Great Lakes Region into the Deep South late tonight. This will lead
to WSW flow overhead. At the surface, areas of weak low pressure
will develop off the East Coast of FL and in the northeast Gulf
during the evening, with a stationary front connecting each. They`ll
shift to the ENE through the night. Meanwhile, a weakening cold
front will quickly cross through our area late overnight, followed
by troughing behind it. This complex synoptic pattern will keep the
highest moisture just off the coast. However, light rain/showers
will be possible along coastal areas, before shifting offshore mid-
late evening. Though, there could be remnant showers through the
night. QPF will likely remain below 0.25" around McIntosh County and
vicinity, with event lighter amounts further north and inland. There
will be plenty of moisture and low stratus, so fog development is
possible overnight. However, guidance indicates 1000 mb geostrophic
flow to remain at least 10-15 kt through the night, suggesting a low
stratus deck to be the most likely outcome through daybreak Monday.
Low temperature will generally be in the lower to middle 40s,
warmer at/near the beaches.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Monday and Tuesday: As a broad upper-lvl trough gradually
shears eastward across southeastern Canada, a reinforcing
shortwave will march through the region on Monday. At the
surface, a front shall reside over portions of northern Florida
and extend into the Atlantic adjacent to the South Carolina
coastline. This pattern will yield north-northwesterly flow with
PWAT values ranging between 0.8 to 1.0". Expect light scattered
showers through Monday morning, and then likely taper off by
the afternoon with rainfall totals less than 0.10 inches. With
limited mid-lvl lapse rates and no appreciable CAPE, convection
remains negligible. Thereafter, a dry, cold front should push
through the region on Monday night and high pressure to build in
behind it. Expect lows to drop into the upper 20s across inland
southeast South Carolina and low to mid 30s elsewhere. This
pattern will result in quiet weather on Tuesday as skies
gradually clear in the morning. Despite the sun returning to the
sky, strong CAA will keep temperatures slightly below average
with highs in the low to mid 50s. It`ll be a couple degrees
colder than the previous night, with temperatures dropping into
the upper 20s across the interior counties and low to mid 30s
near the coastline.

Wednesday: As mid-lvl ridge shifts eastward into the Southeast,
strong subsidence will promote a quiet and rain-free forecast.
Also, increasing WAA will support a noticeable warm-up and yield
temperatures into the low to mid 60s. Expect winds to shift to
the southwest as high pressure situates itself across central
Florida. This will promote anticyclonic flow across the region
and allow overnight lows to be a tad warmer than the previous
nights.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
At the surface, high pressure will continue to dominate the
forecast on Thursday and allow for another rain-free day. Clear
skies and s southwesterly flow will yield temperatures in the
mid to upper 60s on Thursday. However, this quiet and warm
weather only lasts momentarily, as a reinforcing cold front is
expected to sweep across the region on Friday afternoon. This
will promote light rain showers on Friday ahead of the
approaching front. There`s moderate uncertainty pertaining to
this weekend as ensemble spread remains large. Cooler
temperatures will likely return this weekend following the
passage of the front.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
IFR or lower cigs will prevail at CHS/JZI/SAV terminals this evening
and overnight with ample low-lvl moisture and light rain occurring.
Light rain could also reduce vsbys to around 1-3 miles at times,
lowest at CHS/JZI terminals this evening. Even with light rains
departing late evening IFR or lower cigs will continue through
the night as a strong low-lvl inversion holds in place. However,
10-15 kt low-lvl wind fields suggest a low stratus event rather
than fog (or at least dense fog) tonight and/or early morning
Monday. Drier air will begin to shift into the area post daybreak
Monday and sfc winds will be start to increase by late morning
(around 15Z). Expect cigs to improve to high-end IFR by noon,
but persist Monday afternoon.

Extended Aviation Outlook: Lingering periods of MVFR cigs with
occasional IFR cigs expected to persist through Monday night.
Expect improving conditions thereafter.

&&

.MARINE...
Tonight: A frontal system will move through the waters. Expect
NE winds sustained around 10-15 kt this evening, becoming N and
increasing to 10-15 kt with gusts to 20 kt by daybreak Monday.
Seas should average 2-3 ft withing 20 nm, and 3-4 ft for the GA
waters beyond 20 nm. Showers and low clouds could bring
occasional reductions in visibility. But dense sea fog is not
expected.

Monday through Thursday: As a broad upper-lvl trough dominates
the forecast aloft, a reinforcing shortwave will march through
the region on Monday. At the surface, northwesterly flow will
persist as a cold front approaches the local waters. Expect wind
speeds to increase to 15-20 kts with periodic gusts of 24-25
kts on Monday night. Thereafter, winds will taper back and
remain light through mid-week, before a reinforcing cold front
approaches on Thursday night. Winds will shift to southwest as
high pressure situates itself across central Florida. Seas will
range from 3 to 5 ft with some 6 footers reaching into the the
nearshore Charleston and outer Georgia waters on Monday
afternoon. Therefore, a brief period of Small Craft Advisories
will be possible on Monday evening. Afterwards, the swell looks
to ease back as high pressure returns to the Atlantic waters on
Wednesday and conditions rapidly improve.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$

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