682
FXUS62 KCHS 070029
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
729 PM EST Sat Dec 6 2025

.SYNOPSIS...
A frontal system will maintain unsettled weather through early
next week, then cold high pressure will build in. A reinforcing
cold front will move through late next week.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Tonight: The mid-levels will consist of WSW flow overhead. The upper-
level jet streak located to our northeast will move away. At the
surface, a frontal boundary will remain situated well to our south
and southeast. High pressure will be located well to our north.
Models have the rainfall ending from north to south this evening as
drier air begins to nudge into the region from the west. Though,
isolated to scattered showers should persist over McIntosh County
and its vicinity for much of the night. Most areas should receive
little QPF accumulation tonight, except McIntosh County and its
vicinity, which should get less than 0.25". The combination of some
stratus build down this evening, abundant low-lvl moisture
(including wet grounds), and light/calm winds should lead to some
fog formation, mainly after midnight. However, ongoing trends
suggests thick high clouds this evening and guidance indicating an
increase in 1000mb geostrophic winds late night could limit the
window for areas or widespread fog to become dense overnight.
Conditions will continue to be monitored for any potential Special
Weather Statement or Dense Fog Advisory overnight. Otherwise, low
temperatures will range from the upper 30s far inland, to the mid to
upper 40s along the immediate coast.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
A broad upper-lvl trough with reinforcing shortwaves will
continue to dominate the forecast pattern. 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". Also, this will allow deep-layer
onshore flow to enhance low-lvl moisture across the southeast on
Sunday. Expect light to moderate scattered showers Sunday
afternoon with the greatest chance across southeast Georgia.
Recent QPF guidance indicates less than 0.10 inches with
localized higher amounts (0.25 to 0.50 inches) across southeast
Georgia where showers could train and/or linger. Model soundings
indicate a saturated profile below ~750-800 mb with a shallow
isothermal layer, indicating a possible persistent of low
stratus throughout Sunday. With limited mid-lvl lapse rates and
no appreciable CAPE, convection remains negligible. Onshore flow
and cloud cover will mitigate strong radiational heating and
highs will likely only reach into the mid to upper 50s. As the
upper-lvl trough gradually shears eastward, another shortwave
will pass over the region on Sunday night. This will yield light
scattered showers overnight through Monday morning. These
showers will likely taper off by the early afternoon on Monday
with rainfall totals less than 0.10 inches. Expect a dry, cold
front to push across the region on Monday evening/night, and
then high pressure to build into the region behind it. This will
result in quiet weather on Tuesday with skies gradually
clearing throughout the day. Temperatures will remain slightly
below average with highs in the low to mid 50s (with some spots
of upper 50s in Southeast Georgia). It could become quite cold
on Monday and Tuesday night with temperatures dropping down into
the upper 20s inland and then low to mid 30s closer to the
coastline.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As mid-lvl ridge shifts eastward into the Southeast, strong
subsidence will promote a quiet and rain-free forecast on
Wednesday and Thursday. Also, increasing WAA will support a
noticeable warm-up mid-week as temperatures reach into the mid
to upper 60s. However, this pattern only lasts momentarily, as a
reinforcing cold front sweeps across the region on Friday.
Expect increasing cloud cover and strengthening southwesterly
flow aloft to develop 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 SUNDAY THROUGH THURSDAY/...
Periods of MVFR/IFR are likely at CHS/JZI/SAV terminals this evening
and tonight, along with light rains producing MVFR vsbys at times
through about 03Z Sunday. There could be a brief period of VFR
conditions at the terminals prior to midnight, but most guidance
suggests IFR cigs to develop and hold at the terminals until during
the second half of the night. Slow improvement, but prolonged MVFR
cigs are possible at CHS/JZI from 13Z Sunday to 00Z Monday. IFR cigs
should hold at the SAV throughout the day Sunday with additional
rain/showers occurring during the afternoon and possibly occurring
through 00Z Monday.

Extended Aviation Outlook: A relatively prolonged period of
MVFR with occasional IFR ceilings expected through early next
week. This system will likely produce low ceilings and reduced
vsbys. Expect improving coniditons late Monday night.

&&

.MARINE...
Tonight: A frontal boundary located well to the south and
southeast of the coastal waters will support WNW winds in the
10-15 kt range this evening (slightly weaker across Georgia
waters), veering to the NE by daybreak Sunday. Seas should
average 2-3 feet. Showers and low clouds could produce some
visibility reductions at times.

Sunday through Wednesday: A prolonged period of north-
northwesterly flow, driven by a series of shortwaves passing
across the local waters, will dominate through mid-week. Expect
wind speeds to remain rather light with 5 to 10 kts on Sunday,
and then increase to 15 to 20 kts with gusts near 25 kts on
Monday as the aforementioned cold front approaches. Thereafter,
winds will taper back and remain light on Tuesday and Wednesday.
Seas will range 2 to 3 ft on Sunday, and then build modestly to
3 to 5 ft with some 6 footers tapping into the the nearshore
Charleston and outer Georgia waters on Monday evening into
Tuesday. Therefore, Small Craft Advisories will likely be needed
on Monday evening into Tuesday. Afterwards, the swell looks to
ease back as high pressure returns to the Atlantic waters on
Wednesday and conditions rapidly improve.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides will remain elevated Sunday but will be on a
declining trend. Coastal Flood Advisories could be needed for
the Sunday morning high tide cycle, but the current forecast is
for Charleston to fall just shy of the minor coastal flood
threshold.

&&

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

&&

$$

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