North Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

074
FXUS62 KCHS 141115
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
615 AM EST Wed Jan 14 2026

.WHAT HAS CHANGED...
The aviation section has been updated for the 12z TAF issuance.
There are now three key messages, removing the previous first
key message for Tuesday low relative humidity values. Small
Craft Advisories have been issued for the nearshore SC/GA and
outer GA waters from this evening until Thursday night.

&&

.KEY MESSAGES...
- 1) Dangerous fire weather and marine conditions possible
  Thursday into Friday as gusty post-frontal winds combine with
  low humidity.

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

- 3) Below normal temperatures for the second half of the
  weekend into early next week.

&&

.DISCUSSION...
KEY MESSAGE 1: Dangerous fire weather and marine conditions possible
Thursday into Friday as gusty post-frontal winds combine with low
humidity.

Today, a band of isolated to scattered light rain showers may
develop ahead of a passing H5 vort max and jet divergence. High
resolution guidance indicates that the showers may develop by
mid-morning, forming a thin broken line of showers this
afternoon. Using a blend of guidance, some swaths of 0.10" of
rainfall is possible, especially across the inland counties. Any
rainfall will be beneficial ahead of the very dry conditions
expected on Thursday and Friday.

A strong cold front is timed to sweep across the Coastal Plain
of GA and SC this evening. In the wake of the front, winds
should veer from the northwest and develop gusts between 20-25
mph. Winds will be a bit stronger over the Atlantic waters, see
the marine section below for details on winds and wave heights.
On Thursday, guidance indicates active CAA through the day, with
H85 temperatures reaching -5 to -10C by Thursday afternoon. The
air mass will be further dried by downslope flow in the lee of
the southern Appalachians and deep mixing to 4.5 to 5.5 kft. As
a result, sfc dewpoints will fall through the day, pushing well
into the teens by Thursday afternoon. RH values between 25 to 30
percent should be common. The combination of gusty northwest
winds, low RH, and mostly sunny conditions should rapidly dry
fine fuels from any rainfall today. Depending on fuel moisture
levels, a Fire Danger Statement could be needed on Thursday.

The center of the dry air mass will build across the Southeast
U.S. on Friday. Fortunately, the weak pressure gradient should
only support winds between 5 to 10 mph. Dewpoints could be as
low as the single digits at a few locations mid-day Friday, most
areas between 10 to 15 degrees. As temperatures reach around 50
degrees Friday afternoon, RH values may range from the upper
teens west of I-95, to the 20s to the east.

KEY MESSAGE 2: Very cold temperatures will occur Friday
morning, with lows in the upper teens to lower 20s away from the
beaches.

Ensemble guidance continues to be in rather impressive
agreement for Friday morning with some of the coldest
temperatures of the season forecast. The 500 mb wave will be
quickly exiting the region Thursday evening with surface high
pressure approaching from the west. As this occurs, the pressure
gradient will drastically weaken with winds going near calm as
the PBL decouples. PWATs are also forecast to be only around
0.10" (or near daily minimum values) which will further enhance
radiational cooling.

Expect low temperatures in the upper teens west of Interstate
95 in Georgia and inland rural areas of South Carolina (such as
the Francis Marion National Forest). Along and east of the
Interstate 95 corridor to about US Highway 17, expect low
temperatures in the lower to mid 20s. Along area beaches, expect
low temperatures in the upper 20s (including the Charleston
Peninsula). Temperatures will be below freezing for 8 to 12
hours.

The other main concern, is the potential need for a Cold
Weather Advisory. Winds will quickly slacken Thursday night/
Friday morning with the wind chill to temperature differential
decreasing. Still though, Cold Weather Advisory criteria is the
temperature or wind chill expected to fall between 20 and 11
degrees F. There is no minimum wind speed requirement. This
means even though winds will be mostly calm, we will be close to
reaching criteria. Along and west of a Interstate 95 to US
Highway 17 line has a 50 to 75% chance of reaching Cold Weather
Advisory criteria. To the east of this line, has a 20 to 50%
chance of reaching Cold Weather Advisory criteria.

KEY MESSAGE 3: Below normal temperatures for the second half of
the weekend into early next week.

The rex block will start to loose cohesion as a wave over the
eastern Pacific approaches from the west. The downstream effects
of this are another potent shortwave is forecast to dive
southeast out of Manitoba and approach the region Sunday
morning. This will drive another cold front through South
Carolina and Georgia Sunday. Model confidence on this overall
pattern remains very low at this point though and the main
reason appears to be the shortwave coming out of Manitoba. In
particular, how does the rex block evolve and change the
placement of this wave (supported by the WPC Ensemble
Sensitivity Analysis-- ESA-- webpage). There is also a small
chance (~20%) that as the shortwave approaches, a coastal low
will form with 500/ 700 mb frontogenesis commencing out in
front. Temperatures will be borderline for potentially
supporting snow or a rain/snow mix. The probabilistic Winter
Storm Severity Index (WSSI-P) does show a 5-10% chance for a
trace of snowfall from the colder solutions. The latest run of
the GEFS does show more members supporting the wetter solution,
but caution should be exercised here as a lot can change with
the evolution of the rex block and the downstream shortwave. Any
small change could move the precipitation off of the coast and
keep most of the area dry. As observed from the ESA webpage,
model solutions will likely continue to vary until the rex block
and shortwave interaction can be better resolved, which wont
likely be until Friday at earliest.

Behind the cold front, temperatures will again be seasonably
cold Monday with low temperatures in the mid 20s. However, there
is a much larger spread in the interquartile range (IQR) range
(around 8 to 10 degrees) compared to Friday morning of this week
and that makes sense. Ahead of the approaching high pressure,
winds may remain just strong enough (near 5 knots) where wind
chills may dip into the 15 to 20 degrees range, with highest
probabilities again for the furthest inland areas right at 50%,
dropping to 25% along the coast. A Cold Weather Advisory may be
needed. Highs on Monday remain below normal, in the lower to
upper 50s.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions will prevail at CHS/JZI/SAV terminals through 12Z
Thursday. Bands of light showers are forecast to track across
the terminals this afternoon ahead of upper air disturbance.
These showers have been highlighted with a TEMPO in each
terminal, generally between 18-22Z. Winds should favor a west-
southwest direction around 10 kts, with gusts nearing 20kts late
tonight.

Extended Aviation Outlook: VFR conditions will continue for KCHS,
KJZI and KSAV through late week. NW winds could gust to around 20
kts in the wake of cold front on Thursday.

&&

.MARINE...
Today, the marine zones will remain between a developing low
pressure system over the Gulf Stream and a cold front over the
western Carolinas. A weak gradient on the west side of the low keeps
benign marine conditions in place. Shower coverage may gradually
increase across the Atlantic waters this morning, with a band of
light showers expected to sweep across the nearshore waters late
this afternoon.

A strong cold front will cross the area tonight. West-northwest
winds should develop in the wake of the front, with gusts around 25
kts across the Atlantic waters of GA and SC tonight until Thursday
night. As a result, wave heights will build tonight through the
daylight hours on Thursday, peaking between 3-5 ft across the
nearshore with 6 ft beyond 30 NM Thursday evening. Small Craft
Advisories have been issued for all marine zones outside the CHS
Harbor from this evening through Thursday night. The center of a
large area of high pressure will arrive on Friday and may linger
into Saturday, supporting winds around 10 kts with 1-2 ft seas.
Winds should gradually strengthen as a dry cold front sweeps across
the region on Sunday, with gusty winds and building seas, possibly
reaching Small Craft Conditions across a portion of the waters.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory from 7 PM this evening to midnight EST
     Thursday night for AMZ350.
     Small Craft Advisory from midnight tonight to midnight EST
     Thursday night for AMZ352-354.
     Small Craft Advisory from midnight tonight to 4 AM EST Friday
     for AMZ374.

&&

$$

Haines/NED