North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

861
FXUS62 KCHS 311126
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
626 AM EST Sat Jan 31 2026

.WHAT HAS CHANGED...
Near term guidance is beginning to show some consistency on the
possible formation of a cyclonic band of moderate snow setting
up later today roughly in the Metter-Savannah Metro corridor.
Should this band form, it could push snow totals to 2". An
upgrade to a Winter Storm Warning may be needed for Tattnall,
Evans, Inland Liberty, Inland Bryan and Inland Chatham later
today if confidence on the timing and placement of this band
increases. The aviation discussion was updated for the 12z TAFs.

&&

.KEY MESSAGES...
- 1) A significant winter storm is expected to bring moderate to
  major impacts across portions of the South Carolina Lowcountry
  and Southeast Georgia through Sunday morning. Winter Storm
  Warnings and Winter Weather Advisories are in effect.

- 2) Extremely cold temperatures are expected this weekend into
  early next week. Historically cold wind chills are expected
  Saturday night into Sunday morning and an Extreme Cold Warning
  has been issued for the entire area.

&&

.DISCUSSION...
KEY MESSAGE 1: A significant winter storm is expected to bring
moderate to major impacts across portions of the South Carolina
Lowcountry and Southeast Georgia through Sunday morning. Winter
Storm Warnings and Winter Weather Advisories are in effect.

The synoptic reasoning has changed little since Friday.
Cyclogenesis is expected to initiate offshore of the Carolinas
today and tonight in response to intense Gulf Stream low-level
baroclinicity interacting with the approach of a powerful
upper-level system. This system is forecast to dig across the
Carolinas and Georgia tonight as it closes off. Intense DCVA
ahead of the digging shortwave/upper low will steadily increase
across the region. This will result in widespread precipitation
breaking out over much of northern/central portions of South
Carolina and Georgia later this morning which will spread east
and southeast through the afternoon while gradually changing
over to snow. A period of rather intense snow could occur over
the Charleston Tri-County into Colleton County this evening as
the upper low barrels through and the deformation axis along the
backside of the cyclone pivots south into parts of the
Lowcountry. The snow will gradually end from southwest-northeast
through the night as the as the upper low clears the area and a
pronounced dry slot rotates through.

Timing/Snow Amounts/Mesoscale Details: Temperatures will peak
at various times through the day as cold air filters south and
precipitation overspreads the area. Most of the hourly
temperature guidance is likely too warm given their usual bias
of underplaying the impacts of diabatic cooling. Near term
adjustments were made to account for this. This results is a
slightly quicker transition to snow from west-east this
afternoon. Snow should mix with and quickly to change to snow by
mid/late morning well inland with the change over reaching the
Georgia coast by late afternoon. Forecast soundings suggest
sub-freezing temperatures may initially outpace the saturation
of the Dendritic Growth Zone (DGZ) well inland, so precipitation
may briefly start out as a rain/freezing rain/sleet mix, mainly
across far northern portions of Colleton, Dorchester and
Berkeley Counties. But this mixed p-type transition should not
last long before turning to all snow as full cloud ice
nucleation occurs. By sunset, all areas should have transitioned
to all snow.

There are increasing signals that a band of heavy snow associated
with the deformation zone along the northwest flank of the
upper low could pivot south into the Lowcountry this evening as
the upper low pivots through. This could enhance snowfall rates
across portions of the Charleston Tri-County into Colleton
County for about a 3-6 hour period this evening. Near term
guidance has trended upwards because of this with updated storm
totals (utilizing an initial SLR of 12-16:1 increasing to
18-20:1 by this evening) ranging from 4-7" across parts of the
Charleston Tri-County. Elsewhere, amounts will range from 2-4"
the Jenkins-Colleton region with up to 2" in the Candler-
Beaufort region. Winter Storm Warnings are in effect for these
areas. South of I-16, including the Savannah Metro Area, up to
1" of snow is expected and a Winter Weather Advisory remains in
place.

In addition to deformation enhancement, some of the higher
resolution data sets suggest a few bands of locally heavier
snows could impacts areas south of I-16 later this
afternoon/evening. This may result in localized amounts in
excess of 2 inches. These bands are associated with pockets of
enhanced frontogenesis. Frontogenetic bands, especially in the
presence of negative EPV values, are notorious for enhancing
snowfall rates. This is something that will have to be watched
through the day and an expansion of the Winter Storm Warning
south may be needed.

Snow Impacts: Moderate to major impacts are expected in the
Winter Storm Warning area with the most significant impacts
occurring in the Charleston Tri-County. Dangerous to impossible
driving conditions are likely there. Closures and disruptions of
infrastructure may also occur. Minor impacts are likely in the
Winter Weather Advisory area where slick spots could make for
hazardous driving conditions. Vsbys could drop as low as 1/2
mile across parts of the Charleston Tri-County as an area moderate
to heavy snow associated with the aforementioned deformation
axis settles in for about a 3-6 hour period this evening. As
winds begin to gust to 30-35 mph late this afternoon and
overnight in response to strong cyclogenesis offshore, areas of
blowing snow could occur, especially with SLRs likely remaining
above the critical threshold of 12:1 resulting in a very
dry/powdery snow. The risk for impacts from blowing snow will
greatest across the Charleston Tri-County where the highest
snow amounts will likely be found. New snowfall records could be
set at both the KCHS and KSAV airports for January 31 and
February 1. See the climate section below for details.

Lake Moultrie: Winds on Lake Moultrie will increase late this
afternoon and evening. Speeds will reach 20-25 kt with gusts as
high as 30-35 kt. Waves will peak 2-3 ft with local sets in
excess of 4 ft. Lake Moultrie is a fresh water lake. As winds
become gusty and sub-freezing temperatures (30 deg or lower)
settle in, the risk for freezing spray will increase over the
open lake waters and along the downwind side of the lakeshore,
including Pinopolis and Short Stay. This could result in a
glaze of ice on trees, piers and other structures, in addition
to the expected snow.


KEY MESSAGE 2: Extremely cold temperatures are expected this
weekend into early next week. Historically cold wind chills are
expected Saturday night into Sunday morning and an Extreme Cold
Warning has been issued for the entire area.

Through Sunday: Bitterly cold temperatures will settle into the
region tonight as gusty northwest winds persist through
daybreak. Lows overnight have trended down just a bit, ranging
from the mid teens inland to around 20 at the beaches. Wind
chills Sunday morning are expected to bottom out in the 0-5
degree above zero range which is is an extremely rare occurrence
this far to the south. Highs Sunday will be heavily influenced
by a lingering snow pack, especially across the Charleston Tri-
County. Highs will only peak in the lower-mid 30s in the
Charleston Tri-County to the lower 40s near the Altamaha River.
Despite full sun, some areas in the deepest snow pack may not
get above freezing. Some further downward adjustments in the
highs may be needed pending the final area/depth of the snow
pack.

Sunday Night through Tuesday: The mid-levels will consist of a
very strong trough over the East Coast Sunday night into early
Monday, followed by it shifting offshore later Monday into
Tuesday. This will generate northwest flow over our area. At the
surface, High pressure will be over the Lower MS Valley Sunday
night. It`ll gradually shift eastward, passing over FL on
Tuesday. Sunday night, the combination of west northwest winds
ushering colder temperatures in, cooled further by a fresh
snowpack (especially for our SC counties), and plenty of
radiational cooling due to mostly clear skies will cause
temperatures to bottom out in the teens across most of our area,
except the lower 20s along the immediate coast, and a tad
warmer at the beaches. But winds will be light, which will
generally keep the wind chill only a few degrees colder than the
temperatures. But Cold Weather Advisories will still be needed
everywhere. Monday, there should be a noticeable spread in high
temperatures, mostly due to a remaining snowpack over our SC
counties. They`ll range from around 40 degrees near the Santee
River, to around 50 degrees near the Altamaha River. Monday
night, very light southwest winds are expected. Skies will start
out clear in the evening, but clouds will gradually increase
from south to north overnight. This may limit some of the
radiational cooling. Lows should range from the lower 20s inland
to near freezing at/near the beaches. Since winds will be very
light, it doesn`t appear wind chills will drop to 20 degrees or
lower, so we probably won`t need Cold Weather Advisories.
Tuesday, temperatures moderate further with highs ranging from
near 50 degrees near the Santee River to the lower 60s near the
Altamaha River.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
21/12z TAF Discussion:
KCHS/KJZI: Conditions will deteriorate through the day as
precipitation spreads over the terminals. Rain should mix
with/change to snow by early afternoon then become all snow by
late afternoon. An area of moderate to heavy snow with IFR
conditions could impact both KCHS/KJZI after sunset with vsbys
possibly dropping to airfield minimums. Blowing snow could also
have an impact as gusty winds in excess of 25 kt occur and a
snow pack forms. High snow-to-liquid ratios support a
dry/powdery snow which should be easily lofted. Vsbys 1/2SM SN
BLSN were highlighted at both terminals 23-05z. This is also
when any deicing operations will could be at their peak.

KSAV: Conditions will deteriorate through the day as
precipitation spreads over the terminal. Rain should mix with
snow by early afternoon then become all snow late afternoon and
linger into this evening as activity diminishes. Conditions
looks to mostly remain MVFR once lower cigs settle in. The risk
for any snow impacts looks greatest from 21-04z. Wind gusts in
excess of 25 kt are likely.

Extended Aviation Outlook: A cold front may bring flight
restrictions Wednesday, mainly due to rain showers.

&&

.MARINE...
Through Sunday: There is a high probability of gales for all
waters from late this afternoon into Sunday morning. Gale
Warnings are in effect for all legs as a result. Gusts could
get close to storm-force over the the Georgia offshore waters
and the outer portions of the South Santee-Edisto Beach
nearshore leg. An upgrade to a Storm Warning may be needed if
confidence for frequent storm-force gusts increases.

Sunday Night through Wednesday: Surface High pressure will be
over the Lower MS Valley Sunday night. It`ll gradually shift
eastward, passing over FL on Tuesday, then shift offshore
Tuesday night into Wednesday. A cold front will approach from
the west on Wednesday. Winds and seas will be trending lower
Sunday night into Monday. Any remaining marine headlines (most
likely for the GA waters beyond 20 nm) should come to an end by
Monday evening. Winds and seas are expected to remain below
Small Craft Advisory criteria through Wednesday, followed by
deteriorating conditions Wednesday night.

&&

.CLIMATE...
Record Low Temperatures:

February 1:
KCHS: 21/1977
KCXM: 23/1900
KSAV: 23/1977

February 2:
KCHS: 19/1980
KCXM: 17/1917
KSAV: 18/1917

Record Low Maximum Temperatures:

February 1:
KCHS: 38/1980
KCXM: 36/1900
KSAV: 38/1900

February 2:
KCHS: 38/1980
KCXM: 38/1898
KSAV: 38/1951

Record Snowfall:

January 31:
KCHS: 0.6/1977
KSAV: 1.3/1977

February 1:
KCHS: no record established
KSAV: no record established

&&

.EQUIPMENT...
The KCLX radar is operational, but could go down at any time.
Additional repairs are needed.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Winter Storm Warning until 1 PM EST Sunday for GAZ087-088-
     099>101.
     Extreme Cold Warning from 4 PM this afternoon to 1 PM EST
     Sunday for GAZ087-088-099>101-114>119-137>141.
     Winter Weather Advisory from 10 AM this morning to 7 AM EST
     Sunday for GAZ114>119-137>141.
SC...Winter Storm Warning until 1 PM EST Sunday for SCZ040-042>045-
     047>052.
     Extreme Cold Warning from 4 PM this afternoon to 1 PM EST
     Sunday for SCZ040-042>045-047>052.
     Lake Wind Advisory from 6 PM this evening to 10 AM EST Sunday
     for SCZ045.
MARINE...Gale Warning from 6 PM this evening to 7 AM EST Sunday for
     AMZ330.
     Gale Warning from 4 PM this afternoon to 10 AM EST Sunday for
     AMZ350-352.
     Gale Warning from 1 PM this afternoon to 10 AM EST Sunday for
     AMZ354.
     Gale Warning from 1 PM this afternoon to 1 PM EST Sunday for
     AMZ374.

&&

$$

ST/-