North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

733
FXUS62 KCHS 122335
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
635 PM EST Mon Jan 12 2026

.WHAT HAS CHANGED...
No changes have been made to key messages for the week.

&&

.KEY MESSAGES...
1) Dry high pressure will dominate through Tuesday, yielding
low relative humidity values both Monday and Tuesday afternoons.

2) Dangerous fire weather and marine conditions possible as
gusty winds and low humidity arrive behind a mostly dry cold
front Thursday into Friday.

3) Very cold temperatures will occur Friday morning, with lows in
the upper teens to lower 20s away from the beaches.

&&

.DISCUSSION...
KEY MESSAGE 1: Dry high pressure will dominate through Tuesday,
yielding low relative humidity values both Monday and Tuesday
afternoons.

Surface high pressure centered over the southeastern states on
Monday will slowly drift towards Texas on Tuesday. Aloft, broad
troughing will dominate over the eastern CONUS into mid-week as a
closed low north of New England on Monday pushes northeastward.
Given the northwesterly flow aloft, much drier air will be advected
into the region. This is shown through multiple model forecast
soundings, depicting a very dry column of air across southeastern SC
and southeastern GA. The drier air will yield RH values on the order
of 20-30% across the region. With the surface high pressure centered
over the southeastern states, winds across southeast SC and
southeast GA will top out only around 5 to 10 mph Monday and Tuesday
afternoons. While the criteria for a fire weather headline is met in
regards to the RH values, wind speeds are significantly below Fire
Danger Statement/Red Flag Warning criteria. While no fire weather
headlines are anticipated at this time, individuals should be
cautious as fires can spread quickly under these conditions.

KEY MESSAGE 2: Dangerous fire weather and marine conditions possible
as gusty winds and low humidity arrive behind a mostly dry cold front
Thursday into Friday.

Approaching shortwave Tuesday night will encourage the development
of weak low pressure within a front over the Bahamas, which will
lift north well off our coast Wednesday. Current expectation is very
dry air in the low levels will limit the potential for any
significant rainfall over land, though a few showers could work back
over the beaches.

A strong cold front associated with low pressure lifting across New
England  will then approach from the west Wednesday night, crossing
the area early Thursday. Low level moisture is limited ahead of the
front, and, with only modest upper forcing coinciding with the
strongest frontogenesis Thursday morning, the overall rainfall
potential with the front looks very limited.

Of greater concern is the strong gradient in the wake of the front
as high pressure builds in from the west. This, in combination with
peak mixing and downsloping flow in the low and mid levels, will
likely result in wind gusts Thursday afternoon on the higher end of
the guidance envelope, with 25 to 30 mph gusts likely, with some
gusts to 35 mph possible over land. A Lake Wind Advisory will likely
be necessary, with wind over the coastal waters possible gusting to
Gale Force (~10-30% chance) into Thursday night. Additionally, RH
values will be rapidly dropping through the afternoon and evening,
and critical RH`s (<25%) could be approached by late Thursday
afternoon. A faster frontal passage would result in a greater
potential for adverse fire weather conditions later Thursday
afternoon/evening.

Very dry air remains in place Friday, with the 30-50% probability of
RH values of <25% away from the immediate coast. However, the
gradient will be much weaker Friday, so Red Flag Warning conditions
currently look unlikely.

KEY MESSAGE 3: Very cold temperatures will occur Friday
morning, with lows in the upper teens to lower 20s away from the
beaches.

Strong cold and dry air advection will occur in the wake of a cold
front Thursday afternoon and evening. Then, overnight Thursday night,
the gradient will weaken significantly and radiational cooling will
ensue. The guidance envelope shows most likely lows away from the
immediate coast in the upper teens to lower 20s. If several hours of
radiational cooling occurs, lows on the lower end of the envelope,
potentially in the mid to upper teens, are very realistic given dew
points in the lower teens. With light winds, the wind chill will
generally be the same as the temperature, so Cold Weather Advisories
could be needed for much of the area.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR conditions will prevail at CHS/JZI/SAV terminals through 00Z
Wednesday.

Extended Aviation Outlook: VFR conditions prevail for KCHS, KJZI and
KSAV through late week. NW winds could gust to 25 to 30 kt Thursday
afternoon as chilly high pressure builds in quickly behind a strong
cold front.

&&

.MARINE...
Conditions will remain below Small Craft Advisory criteria
through Wednesday as surface high pressure dominates over the
forecast area and adjacent marine waters.

Weak low pressure passes off the coast Wednesday, but a weak
gradient on the west side of the low keeps benign marine conditions
in place despite increased shower chances.

A strong cold front will cross the area late Wednesday night into
Thursday morning, with gusty NW winds developing behind the front
Thursday through Thursday evening. There is currently a low (10-30%)
chance for Gale Force gusts, but at the very least Small Craft
Advisories are likely. Winds and seas subside quickly Friday morning
as high pressure builds in from the west.

&&

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

&&

$$

CEB/CPM/DPB