096
FXUS62 KCHS 031139
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
639 AM EST Wed Dec 3 2025

.SYNOPSIS...
High pressure will prevail today before another frontal system
impacts the area Friday into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
The forecast area will remain between a departing cold front over
the western Atlantic and high pressure centered over the southern
Appalachians today. This morning, high resolution guidance indicates
that an sfc trough or weak backdoor cold front will reach the SC
Lowcountry during the pre-dawn hours. This feature may push south,
slowing or becoming stationary near the Savannah River by late this
morning. Based on satellite trends, cloud cover should decrease
across the SC Lowcountry north of the sfc trough. However, linger
stratus south of the trough and the arrival of afternoon cirrus may
keep the sky across SE GA mostly to partly cloudy through the day.
Using a blend of guidance, high temperatures are forecast to range
in the mid to upper 50s.

Tonight, the center of high pressure will build across the CWA. As a
result, winds across the forecast area should become calm inland
this evening, with little to no wind expected across the coastal
counties late tonight. Given the recent soaking rainfall, the
combination of wet soil and calm winds, there is potential for at
least ground fog by dawn Thursday morning. However, high clouds
sourced from a southern stream system may stream across the region
tonight, limiting the potential for mentionable fog. Low
temperatures may range from freezing inland to the mid to upper 30s
across the coastal counties.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
Thursday: High pressure will quickly loose cohesion in the morning
as ageostrophic convergence quickly turns neutral as a potent mid-
level wave moves east over the Hudson Bay. 850/ 500 mb flow also is
westerly with a mid-level low over the Baja of California. There are
some hints that pieces of PV will advect east Thursday bringing a
chance of precipitation to interior GA. The main limiting factor
appears to be low level saturation. Latest model guidance and
ensemble suites are faster with the overall progression of the
shortwave than this time yesterday though. Therefore, chance PoPs
are now in the forecast Thursday afternoon for interior GA. Expect
temperatures below normal for this time of year.

Friday and Saturday: Ensemble members have come into better
agreement today with the overall synoptic pattern and resultant
sensible weather at the surface. The mid-level low over the Baja of
California is now forecast to quasi- wave break and slow down the
overall group velocity of the long wave trough. However, the phase
velocity of individual wave packets diving southeast out of the
Colorado Rockies actually increases in speed with long wave trough
amplification remaining. The means Friday looks wet as multiple
rounds of PV advect over the region and a weak coastal low forms.
The coastal low will then move northeast off the coast of SC and GA.
Another shortwave will then move overhead Saturday with the best
forcing for ascent (from a RRQ of an upper level jet, PVA and WAA)
being from the Panhandle of FL across GA and coastal SC.
Precipitation totals Friday through Saturday night are now forecast
to be in the 1" - 2" range. One final note on ensemble agreement.
The past two days, model agreement has remained rather poor due to
the potential of a cut off low near the Baja of California. WPC
cluster analysis from the 02.12z guidance now shows all ensemble
members indicating rain on both Friday and Saturday. This agreement
is rather impressive considering yesterdays guidance split, and
caution is advised on the seeming model agreement (the WPC Ensemble
Sensitivity Analysis still shows a majority of model variance coming
from the Baja of California and Hudson Bay lows on Friday).

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
Precipitation could linger across the area on Sunday as the primary
mid-level wave from the Colorado Rockies finally moves east. A cold
front will then push through the region bringing an end to the
precipitation. Temperatures Monday and Tuesday fall well below
normal with freezing temperatures possible Monday night and Tuesday
night.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Prior to the 12Z TAFs, nighttime microphysics indicated a large
area of MVFR ceilings across the terminals. The restrictive
ceilings should remain as a sfc trough or weak backdoor front
pushes over the SC Lowcountry this morning. The passage of the
trough will result in light winds to shift from the northeast
along with lifting of cloud bases. Based on satellite trends,
conditions over KCHS and KJZI are forecast to improve to VFR
between 14-15Z. The sfc trough should slow or becoming
stationary near the Savannah River by late this morning. As a
result, MVFR ceilings over KSAV may linger until early this
afternoon. Also, winds at KSAV may remain from the northwest
through the TAF period.

Extended Aviation Outlook:
Thursday: VFR.

Friday and Saturday: Cloud bases will lower early Friday and reach
IFR conditions. IFR/ MVFR conditions are then forecast to continue
through Saturday. Widespread rainfall is likely, but forecast
soundings indicate no thunder as TAF sites remain on the cool side
of a coastal front.

Sunday: IFR conditions slowly recovering to VFR as a cold front
moves through the region. Precipitation will also come to an end
with winds out of the north/ northwest.

&&

.MARINE...
Today and tonight: No concerns across the marine zones. The pressure
pattern will support generally northwest winds around 10 kts. Seas
will remain between 2 to 3 ft.

Thursday: Northwest winds veering from the north 10 to 15 kt. Seas 2
to 4 ft. No precipitation or marine headlines are forecast.

Friday and Saturday: Winds will veer from the northeast 10 to 15 kt.
Widespread showers and possibly a thunderstorm expected Friday and
Saturday as a coastal low moves northeast. Expect seas 2 to 4 ft.

Sunday: A cold front will cross the waters Sunday with winds out of
the north 10 to 15 kt. Precipitation will come to an end during the
day. Expect seas 2 to 4 ft.

&&

.TIDES/COASTAL FLOODING...
Astronomical tides will continue to rise with the morning high
tide cycles through Friday and remain elevated through the
weekend. Coastal Flood Advisories will likely be needed for
morning high tide cycles, primarily at Charleston Harbor
(Charleston and Coastal Colleton counties) through Saturday
morning.

Friday, astronomical high tides peak (6.8 ft MLLW at Charleston
Harbor and 8.86 ft MLLW at Fort Pulaski) and this is when winds are
forecast to turn from the northeast. Overall, this type of setup can
over perform given the building anomalies from the northeast winds.
Currently, moderate coastal flooding is forecast at Charleston
Harbor and minor coastal flooding is forecast at Fort Pulaski.

&&

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

&&

$$

NEAR TERM...NED
SHORT TERM...Haines
LONG TERM...Haines
AVIATION...Haines/NED
MARINE...Haines/NED