968
FXUS62 KCHS 271946
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
346 PM EDT Thu Mar 27 2025

.SYNOPSIS...
Dry conditions and high pressure will prevail through Saturday,
then rain and thunderstorm chances increase on Sunday and Monday
followed by a strong cold front Monday evening.

&&

.NEAR TERM /THROUGH TONIGHT/...
Rest of this afternoon: Large expanse of surface high pressure
is essentially sitting on top of the local forecast area this
afternoon, providing abundant sunshine...save for some cirrus
streaming through the southern part of the CWA. Temperatures are
running a little cooler today (H8 temps off nearly 4C on the
CHS 12Z sounding vs last evening), reflected in surface temps in
the upper 60s to lower 70s. Forecast max temps were previously
lowered by a degree or two accordingly.

Tonight: Quiet conditions will persist with some increase in
high cloud cover spreading into the region from the S/SW.
Surface high pressure will migrate off the Atlantic coast with
low level flow veering southeasterly in time, which will begin
to draw higher dewpoint air into the region through the
overnight hours. Boundary layer will decouple by early-mid
evening as the afternoon sea breeze exits into the Midlands,
CSRA and east-central Georgia while breaking down. This will
allow for decent radiational cooling conditions, although that
might eventually be offset by increasing low level dewpoints.
That said, lows from the mid 40s well inland to the upper 50s at
the beaches and Downtown Charleston are anticipated. A few
lower 40s could occur across parts of the Francis Marion
National Forest.

Finally, there are several fires still burning across the
region with the largest (Table Rock) in the far upstate near the
NC border. HRRR vertically integrated smoke projections suggest
a decent amount of smoke aloft may eventually spread down
through the Low Country tonight. Will see, but Friday sunrise
could end up rather colorful.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Dry, surface high pressure will sit itself over the western Atlantic
on Friday into Saturday allowing dry conditions and above normal
temperatures to continue. Temperatures will climb into the upper 70s
to low 80s with temperatures being 5-10 degrees cooler along the
coastline for Friday and Saturday.

Following into to Sunday, deep moisture will flow into the region in
the morning as a shortwave approaches. PWATs expected to rise above
1.50" by the afternoon. Scattered to numerous showers will move
through in the afternoon, with few thunderstorms possible.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Showers will continue into Sunday night, as a strong cold front
passes through Monday evening. Ahead of the front, highs will reach
into the low to mid 80s as warm air advection dominates. There is a
decent amount of instability on Monday, with SBCAPE values reaching
over 1000 J/kg in the afternoon hours. Also, lapse rates will range
from 6.2 to 6.5 degree Celsius/km allowing the atmosphere to be
very buoyant and the possibility for some severe thunderstorms
to develop. Recent model runs have been struggling with the
timing of the front, thus there is still major uncertainty
associated with this system. We are still highlight in the a Day
4-8 outlook for thunderstorm risk from SPC.

Behind the cold front, high pressure will build in on Tuesday and
Wednesday. It is possible to see a couple isolated showers either
day as additional shortwaves move through. Despite the strong cold
front passage, highs will reach into the upper 70s to low 80s on
both days.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
27/18z TAF Discussion:
KCHS/KJZI/KSAV: VFR through 28/18z. Several fires continue to
burn across the region with the largest in the far upstate near
the NC border. Vertically integrated smoke projections suggest a
decent amount of smoke aloft may eventually spread down through
the Low Country tonight in Friday morning.

Meanwhile, surface high pressure over the region today will
press off the Atlantic Coast tonight and Friday. Return flow
will begin to spread thicker high cloud cover into the region
late overnight through Friday. In addition, increasing low
level moisture and daytime heating may also lead to a sct-bkn
VFR cloud cover on Friday.

Flight restrictions are possible late this weekend with the
aforementioned showers and/or thunderstorms ahead of the
approaching cold front.

&&

.MARINE...
Easterly winds continue to run a bit gusty across the coastal
waters this afternoon owing to an inverted surface trough well
offshore, particularly across the SC coastal waters with gusts
continuing to push 25 knots at times. Surface high pressure
along the southeast coast this afternoon will be migrating into
the Atlantic waters tonight. This will result in winds
decreasing over the next several hours while veering
southeasterly in time.

Friday through Monday: High pressure will prevail on Friday through
Saturday over the coastal waters. A Small Craft Advisory (SCA) might
be needed for the outer Georgia waters on Saturday night and
continuing until Monday morning, mainly due to 6 foot seas. Ahead of
the approaching cold front, winds will pick up on Sunday and Monday
but should stay below SCA criteria.

&&

.FIRE WEATHER...
Model soundings show deep mixing occurring again today as
downslope trajectories hold aloft. Dewpoints are expected to mix
out into the mid-upper 20s across the interior while dewpoints
at the coast look to remain somewhat elevated as onshore winds
develop with a robust sea breeze circulation. Despite this,
RH values look to bottom out in the 15-22% range inland with
22-55% across the coastal counties, highest at the beaches. The
combination of critically low humidity away from the coast with
ongoing drought conditions and dry fuels will result in another
afternoon of elevated fire danger. Thankfully, wind gusts will
not be as great as the past few days, except at the coast with
the sea breeze. Per coordination with adjacent offices, a Fire
Danger Statement has been issued for all but the Georgia coastal
zones and all of McIntosh County, GA, from Noon to 8 PM. RH
values look too high along the Georgia coast to support a
statement at this time. A Burn Ban remains in effect for the
entire state of South Carolina until further notice.

&&

.EQUIPMENT...
The KCLX radar remains offline for dome maintenance through
April 1, 2025. Radar data will not be available during this
time. Users are urged to use adjacent WSR-88D sites which also
cover much of Southeast South Carolina, Southeast Georgia and
the adjacent coastal waters. These include:

KCAE - Columbia, SC
KLTX - Wilmington, NC
KJAX - Jacksonville, FL
KVAX - Moody AFB, GA
KJGX - Robbins AFB, GA

&&

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

&&

$$

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