278
FXUS62 KCHS 091107
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
607 AM EST Tue Dec 9 2025

.SYNOPSIS...
High pressure will extend across the region for much of the
week. A cold front will push offshore Thursday morning with
another cold front possibly moving through late in the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, the pattern will be broadly cyclonic as low
amplitude troughing covers the southeast and south-central
CONUS. At the surface, high pressure will start the day
stretching from New England, across the Southeast, and into the
lower MS Valley. This high pressure will then persist across the
Southeast and settle nearly right on top of the forecast area
by the end of the day. With plentiful dry air (precipitable
water values ~0.25") and no forcing, the forecast is dry. The
main change today will be the long awaited scattering any
lingering low stratus this morning followed by full sun in the
afternoon. While the return of the sun will certainly be
welcomed, it does not mean it will be a warm day. Instead low-
level thickness values support another very chilly day. Forecast
highs are for upper 40s across southeast SC and upper 40s and
low 50s for southeast GA. Such values would be on the order of
15 degrees below normal.

Tonight: With high pressure on top of the forecast area and
clear skies, we should see good radiational cooling conditions
tonight. This will yield lows solidly in the upper 20s inland,
with a transition zone from low to mid to upper 30s as you get
closer to the immediate coastline.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Dry high pressure will prevail through the period.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
Guidance has continued to delay the passage of the strong cold
front, now showing it moving through late Sunday and maintaining
relatively warm temps over the weekend.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
The 12z TAF period begins with widespread MVFR stratus across
the forecast area including KCHS, KJZI, and KSAV. The main
forecast challenge will be timing when the stratus will finally
scatter out and conditions return to VFR. Based on the solid
appearance of the stratus on satellite imagery it will likely
take some time. Current thinking is it will first occur at KSAV
by the late morning, followed by KCHS and KJZI in the early
afternoon.

Extended Aviation Outlook: VFR.

&&

.MARINE...
Today through tonight: The day will start with north-northeast
winds solidly in the 15-20 knot range, with gusts into the low
20 knot range. Wind speeds will then steadily diminish through
the day, becoming 5-10 knots by sunset for much of the local
waters. Overnight, winds will be around 5 knots out of the
northwest and becoming more westerly with time. Seas will start
off the morning in the 3-5 knot range, with a diminishing area
of up to 6 ft in the Charleston County waters and the outer GA
waters. Seas will then gradually decline through the overnight,
becoming mostly 3-4 ft by sunrise Wednesday. Lingering Small
Craft Advisory conditions for the Charleston County waters and
outer GA waters will come to an end by mid morning.

Brief Small Craft Advisory conditions expected for most waters
late Wednesday afternoon through Wednesday night.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 10 AM EST this morning for AMZ350-
     374.

&&

$$

NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...BSH/JRL
MARINE...BSH/JRL