North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

564
FXUS62 KCHS 170629
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
129 AM EST Wed Dec 17 2025

.SYNOPSIS...
High pressure will prevail through Thursday before a cold front
pushes offshore Friday morning. High pressure returns during
the weekend, followed by another cold front arriving early next
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Prior to Daybreak: Aloft, a weak/broad ridge remains directly over
the Southeast while sfc high pressure centered across the western
Atlantic extends across the Southeast. Latest sfc obs indicate a
light/calm wind across most areas, which is likely to persist
through daybreak. Strong radiational cooling during the first half
of the night has helped temps dip into the low-mid 30s inland to
upper 30s/around 40 near the coast. Temps could lower another 1-2
degrees during the next few hours, but further cooling will likely
be limited due to an increase in high clouds arriving from the west
late night. High clouds will also play a limiting factor in fog
potential within a few hours prior to daybreak, especially across
inland areas where temps are coldest. However, sfc dewpt temps
increasing into the upper 30s across southern areas, a light/calm
wind, along with favorable condensation pressure deficits depicted
on some model guidance, suggests patchy fog could develop late
across Southeast Georgia and persist for a few hours prior to high
clouds thickening across the local area approaching daybreak.

Today: Aloft, the axis of a weak/broad ridge over the Southeast will
shift offshore early, favoring a southwest flow across the region
ahead of h5 vort energy traversing the Deep South. At the sfc, high
pressure extending across the area from the Atlantic will remain the
dominant weather feature, resulting in dry/warmer conditions with a
light southwesterly wind for the day. Although high clouds are
expected to spread across the region and thicken, temps should still
reach the mid 60s for most areas, and potentially the upper 60s
south of I-16 across Southeast Georgia.

Tonight: Aloft, little change in the overall pattern occurs, but the
first signs of h5 vort energy should enter the region after
midnight. The most notable change occurs at the sfc, with guidance
supporting the development of a coastal trough along the
southwestern edge of the Atlantic high offshore. Increasing low
clouds will likely accompany this feature, spreading across
Southeast Georgia, then Southeast South Carolina starting during the
evening. By midnight, sufficient low-lvl moisture and forcing
supports few to scattered showers developing across nearby coastal
waters and shifting onshore, impacting most beaches south of the
Charleston vicinity across southern Southeast South Carolina and
Southeast Georgia. Activity should eventually make a push inland,
resulting in rainfall amounts around 1/10 of an inch in spots prior
to sunrise. Overnight lows will be considerably warmer than the
previous night, generally ranging in the mid-upper 40s inland to low-
mid 50s near the coast.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
Thursday: Precipitation chances will gradually increase as a
powerful mid-lvl shortwave and associated cold front propagates
towards the Southeast. Ahead of this feature, low-lvl south-
southwesterly flow will advect warm and humid air into the region,
yielding PWAT values ~1.5 inches by the afternoon. Model cross
sections suggest forcing ahead of the shortwave will be modest as
DPVA increases + the passing of the subtropical jet streak aloft.
It`s important to note that SBCAPE values remain quite low (~200-300
J/kg), but this might not matter with enough lift along the cold
front. This should at least result in some low-topped convection
right along the boundary. Expect precipitation to develop in the
early morning hours, and then slowly expand across the region
throughout the daytime. Highest chance of hearing a few rumbles of
thunder will be in the afternoon into the late evening as the
frontal zone interacts with the warm, moist pre-frontal airmass. A
slight chance of thunderstorms has been introduced across the region
to address this potential. Rainfall amounts remain light with ~0.5
inches expected in the span of 24 hrs. Overnight temperatures will
remain mild due to the overcast skies with lows ranging from low to
mid 50s.

Friday: Broad mid-lvl troughing will extend into from the Bluegrass
region into the Deep South as the associated cold front progresses
across the region. It`s possible to a continuation of some light
showers in the morning before the cold front passes through. There
has been a bit of uncertainty in the timing of the front amongst
guidance, however the early morning hours (before 10AM) look the
most reasonable. Thereafter, high pressure is expected to build into
the region from the west and skies should gradually clear throughout
the day. This will yield temperatures in the low to mid 60s across
the Lowcountry. Overnight lows will be a bit cooler than the
previous couple nights with temps. dipping into the low 30s across
the interior counties and upper 30s to low 40s closer to the
coastline.

Saturday: Expect a return of quasi-zonal flow aloft as the
aforementioned shortwave continues to progress offshore. At the
surface, high pressure will situate itself across the region and
yield cool and dry conditions. Expect sunny skies + light winds as
temperatures moderate back to near normal. It looks like another
cold night is in-store with lows dropping into the upper 30s to low
40s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
Expect high pressure to prevail for the weekend with signals that
another cold front to approach the region late on Sunday, however
confidence remains low with the timing and impacts of this at the
moment. Temperatures will moderate back to above normal on
Sunday into early next week.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions will prevail at CHS/JZI/SAV terminals through 06Z
Thursday. However, shallow ground fog could develop at the terminals
between 09Z-12Z this morning, primarily at CHS/JZI where high clouds
are latest to arrive.

Extended Aviation Outlook: Periods of MVFR possible on Thursday and
Thursday night as increasing cloud cover and showers might result in
lower ceilings and vsbys. A risk for low-lvl wind shear could
develop Thursday night as a strong, pre-frontal low-level jet (45-50
kt) pushes east through the region. Conditions should improve on
Friday behind the passage of the cold front.

&&

.MARINE...
Prior to Daybreak: High pressure will remain in control for the
night with no marine concerns expected across local waters.

Today and Tonight: High pressure will prevail across the western
Atlantic, leading to quiet marine conditions through the day. In
general, north winds will turn more easterly this afternoon,
remaining around 10 kt or less. Seas will range between 1-3 ft.
Overnight, a coastal trough is anticipated to develop along the
southwestern edge of the Atlantic high, which should lead to
scattered showers and possibly a few thunderstorms across local
waters during the second half of the night. Additionally, a slight
uptick in easterly winds and seas are possible, with wind gusts in
the 10-15 kt range and seas between 2-4 ft (highest across outer
Georgia waters).

Thursday through Sunday: Situated between a weakening high offshore
and an approaching shortwave from the west, expect the pressure
gradient to gradually tighten across the local waters on Thursday.
The period of largest concern remains to be on Thursday night into
Friday ahead of the approaching cold front. Southwesterly winds will
become elevated with speeds of 15 to 20 kts with gusts of 25 kts
possible. Also, east-southeasterly swell will mix into the waters
with seas ranging from 3 to 5 ft with some 6 footers reaching into
nearshore South Carolina and outer Georgia waters. Small Craft
Advisories will likely be needed on Thursday evening into
Friday.

&&

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

&&

$$

NEAR TERM...DPB
SHORT TERM...Dennis
LONG TERM...Dennis
AVIATION...Dennis/DPB
MARINE...Dennis/DPB