North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

311
FXUS62 KCHS 291714
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1214 PM EST Mon Dec 29 2025

.SYNOPSIS...
A strong cold front will push offshore this afternoon. High
pressure will then prevail for the remainder of the week.
Another cold front could affect the area next weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Update: Near term guidance has been consistent in keeping the
thin line of showers with the front pretty well in tact as it
crosses the area. Pops were increased to 40% for all areas and
the QPF was nudged up slightly based on these trends and
upstream radar observations. The rest of the forecast is on
track.

Today: Strong cold air advection (CAA) in the wake of a
powerful shortwave rotating around the base of the upper low
north of the Great Lakes will push a cold front across the
Southeast U.S. today with the front progged to clear the coast
during the mid-afternoon hours. Pre-frontal warm air advection
(WAA) aided by a moderate low-level jet will allow for one more
warm day across the Lowcountry and Southeast Georgia despite
increased cloud cover. Highs are poised to warm into the upper
60s/lower 70s before temperatures level out and begin to fall
after FROPA with the onset of strong CAA. The corridor of deep
layered forcing associated with the shortwave is forecast to
pass by well to the north, but modest 850 hPa theta-e advection
ahead of the front coupled with a ribbon of PWATs rising to
1.25-1.35" and low-level forcing right along the leading edge of
the frontal surface itself could support a narrow band of
showers as the front propagates east across the area. This is
scenario is represented rather well by the various simulated
reflectivity products off the CAMs. Pops around 40% were
highlighted today, mainly confined to the timing of the front.
Any rainfall should be very light given the rapid progression of
the line, likely only averaging a trace to a few hundredths.
Conditions will become rather breezy after daybreak with gusts
nearing 30 mph at times. Gusts should remain below Wind Advisory
criteria. See the Lake Wind section below for expected
conditions on Lake Moultrie.

Tonight: The cold front will be offshore by sunset with strong
CAA dominating through the evening hours. The intensity of the
CAA will weaken after midnight as high pressure over the Plains
builds east. The gradient will remain somewhat enhanced through
the night, so winds will remain elevated. Lows are expected to
bottom out in the upper 20s well inland to the mid 30s at the
beaches. Wind chill values could briefly touch 20 degrees across
far interior Southeast Georgia just before daybreak Wednesday.
This is right at Cold Weather Advisory criteria. The situation
looks too brief and marginal to support the issuance of a Cold
Weather Advisory at this time, but the 29/00z HREF did show
probabilities 40-60% of reaching advisory thresholds. The need
for an advisory will be reassessed with the noon forecast
package. Wind chills will otherwise drop into the lower-mid 20s
across the remainder of the Lowcountry and Southeast Georgia.

Lake Winds: RAP soundings across Lake Moultrie show a 200-300
ft marine layer holding over the open lake waters this morning
into the early afternoon hours ahead of the approaching cold
front. Despite adjacent land areas becoming gusty, the marine
layer should subdue winds a bit with conditions largely holding
below Lake Wind Advisory criteria until FROPA at mid-afternoon.
The marine-layer will quickly mix out after FROPA with soundings
showing thermal profiles becoming increasing favorable for
vigorous mixing with the onset of post-frontal CAA. Expect
winds to reach 15-20 kt with gusts to 25 kt by mid-late
afternoon then peaking 20-25 kt with gusts to 30 kt this evening
as CAA maxes out. Winds will then quickly diminish after
midnight as CAA begins to wane. A Lake Wind Advisory is in
effect from 3 PM until 1 AM. Waves will build 2-3 ft with the
highest winds and strongest wave action occurring over the
central and southeast portions of the lake.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
Much cooler conditions expected for Tuesday and Wednesday as
the cold air mass lingers across the region. Highs on Tuesday
will barely get up into the 50s as cold air advection (CAA)
continues. Overnight into Wednesday CAA ceases as winds weaken,
allowing for radiational cooling to become the primary driver of
how much we cool. Areas inland are expected to dip down into
the mid 20s, and with the winds remaining light wind chills are
not expected to reach into cold weather advisory criteria. Areas
along the coast will be a bit warmer in the upper 20s to lower
30s. With weak northwesterly flow persisting on Wednesday, ample
sunshine will begin to bring a little closer to normal in the
mid 50s across the region.

Overnight, lows dip down into the mid 30s across inland areas
while areas near the beaches are a bit warmer in the upper 30s
to lower 40s. A weak front, noted mostly by a shift in winds,
moves through on Thursday with highs near normal in the lower
60s are expected.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
Temperatures continue to moderate on Friday as a warm front
begins to move into the region, though it looks to stall
somewhere across the forecast area. Areas behind the front will
likely make it up into the mid 60s, while areas ahead of the
front a couple degrees cooler in the upper 50s to lower 60s. A
weak shortwave looks to move across the area on Saturday,
accompanied by a surface low pressure system, bringing a chance
for light to moderate rain showers along with temperatures in
the lower to upper 60s.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Prior to the 18Z TAFs, a fine line of showers was located generally
over the I-95 corridor, moving east around 25 kts. This band should
bring a round of showers to the terminals around the onset of the
18Z TAFs. Until the passage of the showers, terminals should
experience MVFR ceilings and gusty SW winds. In the wake of the line
of showers and cold front, conditions should improve to VFR with
gusty west-southwest winds. Gusty conditions will likely remain
through this evening with strong H85 CAA. The rest of the TAF period
should feature steady northwest winds and VFR.

Extended Aviation Outlook: VFR conditions will prevail through
the week.

&&

.MARINE...
Through Tonight: Small Craft Advisories remain in effect for
all waters. Southwest winds will increase to advisory levels
later this morning into the afternoon as low-level wind fields
increase ahead of an approaching cold front. Cold nearshore
waters may limit mixing somewhat in the WAA regime ahead of the
front, but frequent gusts to 25 kt still seems likely. Mixing
profiles will become increasingly favorable for robust mixing
late this afternoon into tonight as the cold front clears the
coastal waters and post frontal CAA peaks. Northwest winds will
peak 20-25 kt with gusts to 30 kt with 20 kt with gusts to 30 kt
in the Charleston Harbor. There is about a 40% chance for
frequent gusts to 35 kt gales to occur in the far eastern
portions of the South Santee-Edisto Beach nearshore leg, but the
impacted area looks too small to justify an upgrade to a Gale
Warning at this time. Winds will begin to diminish late as CAA
begins to wane. Peak seas will build to 3-5 ft nearshore and 5-7
ft over the Georgia offshore waters. Waves in the Charleston
Harbor will reach as high as 2 ft.

Blow Out Tides: Strong offshore winds could result in tides
dropping to -1.0 ft MLLW at both Fort Pulaski and Charleston
Harbor at low tide this evening. Levels should remain above
critical low water thresholds of -1.5 ft MLLW in the Charleston
Harbor and -2.0 ft MLLW at Fort Pulaski. Mariners should still
exercise caution as some structures that are typically
underwater could become exposed and pose a risk to navigation.

Tuesday through Friday: Conditions continue to improve
throughout the day as northwesterly winds weaken and seas calm,
allowing for the small craft advisories to expire. Winds remain
out of the northwest overnight and throughout most of Wednesday
as surface high pressure builds across the southeast. Winds
pickup overnight into Thursday as a front moves towards and then
through the area, bringing the waters from Savannah to Altamaha
Sound 20-60nm out to Small Craft Criteria as winds gusts near
25 knots for a few hours Thursday morning. Westerly winds remain
gusty throughout the day, weakening overnight into Friday.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Lake Wind Advisory until 1 AM EST Tuesday for SCZ045.
MARINE...Small Craft Advisory until 1 AM EST Tuesday for AMZ330.
     Small Craft Advisory until 5 AM EST Tuesday for AMZ350-352-354.
     Small Craft Advisory until 1 PM EST Tuesday for AMZ374.

&&

$$

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