748
FXUS62 KCHS 050224
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
924 PM EST Wed Dec 4 2024

.SYNOPSIS...
High pressure will prevail through tonight. A cold front will
push across the area Thursday, with the return of high pressure
into the weekend. A storm system could impact the area early
next week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Temperatures have remained steady or slightly warmed since early
this evening. As a cold front pushes over the southern
Appalachians late tonight, cloud cover, WAA, and southwest winds
will increase across the forecast area. The hourly temperatures
tonight should gradually warm after midnight across the CWA.
The updated forecast will feature adjustments to the hourly
temperatures, winds, and sky.

Lake Winds: Although warm advection will limit the mixing potential
overnight, geostrophic winds at 1000 mb are as much as 35-40 kt
across Lake Moultrie during the second half of the night. These
winds along with the pressure gradient tightening across the area
will produce gusty winds supportive of a Lake Wind Advisory
across Lake Moultrie after midnight.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Thursday and Thursday night: With the high pressure shifted
offshore, strong southwesterly wind will allow for some decent WAA
to occur. Temperatures are expected to reach almost normal with
highs in the low to mid 60s. However, these warm temperatures do not
last long. A cold front passes through the area Thursday evening
bringing back the cold weather. Along with this cold front, winds
will shift more westerly ahead of the front and then more
northwesterly after the front. This hard shift of the winds should
limit the amount of moisture associated with this front, especially
over interior Southeast Georgia. Breezy conditions are expected
Thursday with gusts up to 25 mph over the forecast area and 25-30 kt
across Lake Moultrie. A Lake Wind Advisory has been issued through
Thursday afternoon. The front will clear the coast Thursday night
with a reinforcing shot of post-frontal CAA and drop lows into mid
to upper 20s inland to low to mid 30s along the coast.

Friday and Friday night: Post frontal CAA will dominate most of
Friday and keep temperatures rather cold under mostly clear skies,
with highs in the mid to upper 40s across southeast South Carolina
and upper 40s to lower 50s across southeast Georgia. Winds will not
be as breezy as Thursday, with winds from the NNW at 5 to 10 kt. By
Friday night, winds should decouple and allow for some decent
radiational cooling to occur. Expect lows to drop to the low to mid
20s inland and low to mid 30s along the coast.

Saturday: On Saturday, a upper level ridge will begin to build into
the area and highs will warm into the 50s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
With the upper-level ridge and clear skies dominating most of the
extended period, highs should reach into the 60s on Sunday and will
increase to the mid 70s for Tuesday. It will be rain-free up until
Monday night/Tuesday as a storm system begins to descend into the
region. With guidance differing on the exact timing of this system,
showers could begin as early as Monday night with the greatest
chance closer to the middle of next week.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
0Z TAFs: A cold front is timed to sweep across the southern
Appalachians late tonight, push across the terminals Thursday
afternoon. Southwest winds are forecast to gradually strengthen
across the terminals tonight, developing gusts between 20-25 kts
at KCHS and KJZI around 10z and KSAV by 15Z. Forecast sounding
indicate that a LLVL jet will increase over the region late
tonight, resulting in low level wind shear between 10-16Z at
KCHS and KSAV, possibly KJZI. Gusty west winds should begin to
decrease Thursday afternoon as the front approaches. Winds
should shift from the northwest and decrease between 22-0z.
Ceilings should remain VFR through the TAF period, however, some
MVFR bases are possible with FROPA.

Extended Aviation Outlook: A cold front pushing through the area
Thursday evening will result in southwesterly gusts around 20 kt at
all terminals Thursday afternoon. Otherwise prevailing VFR through
the weekend.

&&

.MARINE...
Tonight: High pressure will be in control across local waters for
much of the night, but the pressure gradient will steadily tighten
after midnight and through daybreak well ahead of a cold front
approaching from the northwest. Low-lvl wind fields increasing to 40-
50 kt not far inland and 1000 mb geostrophic winds as strong as 30-
35 kt will support Small Craft Advisory level conditions across
nearshore SC waters and outer GA waters after midnight, with event
the potential of a few gusts up to Gale Force across northern SC
waters off the Charleston County Coast around daybreak. Recent
guidance indicates that Gale force gusts may begin across the
Charleston Co. near shore waters late tonight and continue into
Thursday afternoon, Gale Warning has been issued. Seas will
response to increasing winds accordingly, building to as high as
4-6 ft across nearshore waters off the Charleston County Coast
late, and up to 3-5 ft across remaining coastal waters (largest
across outer Georgia waters).

Thursday through Monday: Surface high pressure across the Southeast
will prevail before a cold front pushes offshore Thursday night. SW
winds will surge ahead of the front and Small Craft Advisories have
been issued for all marine zones (including the Charleston
Harbor) through Thursday night. Expect gusts around 25-30 kt
where SCAs have been issued. Gusts across the nearshore off the
Charleston County coast should peak around 35 kt Thursday
morning. Elevated winds veering out of the north will continue
through Friday as high pressure builds into the region. Winds
will then back out of the south over the weekend, averaging
10-15 kt. Seas on Thursday will range 3-5 ft with some 6 footers
breaching the Charleston County waters, before dropping down to
2-4 feet by Friday.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Lake Wind Advisory from 1 AM to 4 PM EST Thursday for SCZ045.
MARINE...Small Craft Advisory from 5 AM to 5 PM EST Thursday for AMZ330.
     Small Craft Advisory until 5 AM EST Thursday for AMZ350.
     Gale Warning from 5 AM to 3 PM EST Thursday for AMZ350.
     Small Craft Advisory from 2 AM Thursday to 8 AM EST Friday for
     AMZ352.
     Small Craft Advisory from 2 AM to 4 PM EST Thursday for AMZ354.
     Small Craft Advisory from 1 AM Thursday to 8 AM EST Friday for
     AMZ374.

&&

$$

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