206
FXUS62 KCHS 021159
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
759 AM EDT Sat Aug 2 2025

.SYNOPSIS...
A cold front will pass through today, before stalling to the
south late weekend, then remaining nearby into next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, a broad trough expanding across the Midwest to
Northeast United States will gradually force a slow moving cold
front across the local area this morning into afternoon. The front
will usher in noticeably cooler air, mostly within a light north-
northeast sfc flow in its wake while an abundance of cloud cover
remains, but will also remain the forcing mechanism responsible for
shower/thunderstorm activity occurring in a moist and unstable
environment across Southeast South Carolina and Southeast Georgia
this afternoon. High temps should range in the mid 80s north of the
front, but still warm into the lower 90s south of this feature,
indicating the greatest potential for a few stronger and/or perhaps
isolated severe thunderstorm capable of wet microbursts occurring
across Southeast Georgia this afternoon and/or early evening.
However, PWATs near 2.25 inches, moderate/high instability (SBCAPE
around 3000-3500 J/kg) and slower storm motions will remain across
the entire area, indicating the potential for locally heavy rainfall
at times with multi-cellular thunderstorms this afternoon into early
evening. The bulk of heavier rains should occur near the passing
front, so with time become more focused across Southeast Georgia
late afternoon into early evening hours. This aligns up well with
WPC`s Excessive Rainfall Outlook, displaying a Slight Risk for
excessive rainfall for much of coastal South Carolina and across
Southeast Georgia today, although the bulk of flooding concerns near
the coast should remain along and south of Beaufort, SC. Flood
Advisories and/or Flash Flood Warnings could eventually be needed.

Tonight: The cold front is anticipated to shift a bit more south
with time, eventually departing the local area by late evening,
allowing stable high pressure to wedge southward across Southeast
South Carolina and Southeast Georgia for much of the night. Shower
and thunderstorm activity should become more focused across southern
areas with the front and less widespread with time due to diurnal
heat loss and a worked over environment. However, lingering moisture
and the front nearby suggest the potential for few to perhaps
scattered showers and thunderstorms overnight. Low temps will be
cooler than previous nights, generally dipping into the upper
60s/lower 70s inland to mid 70s near the coast.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
The short term revolves around cooler temperatures climbing back
towards normal, with unsettled conditions sticking around. By Sunday
morning, the front looks to start out along the GA/FL border and
nudge itself northwards ever so slightly throughout the day, with a
strong surface high over the northeast states. Aloft, a very weak
trough axis tries to develop over the MS/AL/GA region, with weak
scattered shortwaves rounding the base of the trough and moving
overhead. Ensemble situational awareness tables (ESATs) show
precipitable water (PWATs) values between 2 and 2.25", which is
right at the 90th percentile of climatology for this time of the
year, so there is plenty of moisture available for the shortwaves to
create thunderstorms from. As for instability, we`ll have to see
exactly where the front ends up, but with the region on the
northside of the front instability values are generally well below
1000 J/kg, plenty for general thunderstorms but likely not enough
for any severe weather. So, main risk from any thunderstorm activity
will be lightning and locally heavy rainfall given the moist
antecedent conditions and weak steering flow aloft. Sunday will
likely be the coolest day of the short/long term given the fresh
push of cool air, with afternoon highs expected in the mid 70s to
mid 80s inland, and lower to mid 80s along the coast.

Heading into the start of the work week, the pattern doesn`t change
much overall as the aforementioned trough continues to slowly shift
eastwards, and the stalled front remains between the surface high to
the north and the surface low over the Atlantic. This will continue
our daily chances for scattered showers and thunderstorms with the
primary risk being locally heavy rainfall, and with the lack of
instability severe weather is not expected. Temperatures will begin
their slow rise towards normal given weak warm-air advection in the
mid levels, resulting in highs in the upper 80s to lower 90s by
Tuesday.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
Ridging attempts to build back across the region as a narrowing
trough moves out of the central US and towards the east coast
throughout the week. The high pressure wedge will continue to hold
to our north with a potential surface low offshore the Carolinas.
Periodic chances for rain are forecast with shortwave energy at play
and deep moisture still in place. Seasonal temperatures in the upper
80s to lower 90s are expected to return to the region through most
of next week.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A front will slowly sag southward today, leading to prevailing
or tempo IFR cigs for a few hours at all terminals early this
morning that slowly transition to MVFR between 14-16Z, then VFR
prior to afternoon showers/thunderstorms. Tempo MVFR/IFR
cigs/vsbys are then possible with afternoon/evening showers and
thunderstorms. Prevailing -SHRA VCTS groups have been added
during afternoon and early evening hours at all terminals.
Adjustments to flight restrictions will likely be required as
convective activity/trends become more clear. MVFR cigs could
then return at all terminals overnight post showers/thunderstorms.
At this time, confidence is higher that lower cigs will prevail
at the SAV terminal for much of tonight, closer to the front
departing to the south.

Extended Aviation Forecast: As a reasonably strong cold front stalls
nearby this weekend, brief flight restrictions will be possible as
showers and/or thunderstorms develop along this boundary through
early next week.

&&

.MARINE...
Today and Tonight: A cold front will slowly sag southward across
local waters this morning, likely shifting across South Carolina
local waters early, then eventually reaching Georgia waters late
morning into the afternoon. This feature along with ample instability
should support another round of scattered to widespread showers
and thunderstorms, some of which could become strong and/or
severe with damaging wind gusts. Outside of convective activity,
the pressure gradient will not be all that impressive, especially
during the day when convective activity and/or outflows muddles
wind fields. However, east-southeast winds are likely to turn
north-northeast behind the front, generally peaking in the 10-15
kt range while seas average between 2-3 ft. Heading into the
night, convection could be ongoing, particularly across Georgia
waters closer to the front, followed by a modest tightening of
the pressure gradient and northeasterly surge of winds during
the overnight period. In general, northeast winds should
increasing to the 15-20 kt range by around midnight, starting
across northern South Carolina waters and the Charleston Harbor,
followed by remaining waters late. Seas will also respond by
building up to 3-4 ft post fropa.

Saturday: Saturday will see chances for showers and thunderstorms
increase throughout the day, with northeast winds also increasing to
10 to 15 knots across coastal South Carolina and up to 10 across
coastal Georgia, gusting to near 20 knots. Wave heights of 2 to 3
feet.

Sunday into Wednesday: Daily chances for showers and thunderstorms
continue. Northeast winds will increase on Sunday, sustained in the
lower to upper teens with gusts into the upper teens to lower 20s,
strongest across coastal and offshore South Carolina Waters where a
Small Craft Advisory may be needed. Expect much of the same Monday
and Tuesday, albeit with weaker winds.

Rip Currents: Swells will be increasing into the beginning of the
week, resulting in moderate rip current risk for Charleston County
beaches on Sunday.

&&

.CLIMATE...
Record Precipitation:

August 2:
KSAV: 1.81/1990

&&

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

&&

$$

NEAR TERM...DPB
SHORT TERM...APT
LONG TERM...APT
AVIATION...APT/DPB
MARINE...APT/DPB