854
FXUS62 KCHS 021841
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
241 PM EDT Sat Aug 2 2025

.SYNOPSIS...
A cold front will stall nearby and linger in the vicinity into
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Aloft, a broad trough continues to expand from the Midwest into the
Northeast U.S. At the surface, a cold front currently located
across the Altamaha River will bring noticeably cooler and
drier air behind it under light north to northeast surface flow.
The front will act as the primary forcing mechanism as well as
the focus for convection this afternoon and evening, though
additional lift from weak embedded shortwave energy aloft will
contribute to scattered to numerous showers and thunderstorms,
mainly during peak heating hours. Temperatures are expected to
rise into the mid 80s north of the front, while areas farther
south will still warm into the upper 80s to lower 90s.

Across Southeast South Carolina, instability appears modest
with SBCAPE values peaking around 1500 J/kg due to less unstable
air, keeping the risk for strong/severe storms low. However,
instability increases significantly across Southeast Georgia,
where SBCAPE values approach 3000 J/kg. This environment could
support a few stronger storms capable of damaging winds/wet
microbursts. Additionally, PWATs near 2.25 inches combined with
slow storm motions (~10 kt) will enhance the risk for locally
heavy rainfall and quick downpours. Because the front will act
as a focus for convective activity, this will result in the
greater coverage and rainfall amounts confined to an area
roughly south of the Savannah River and north of the Altamaha
River. Additionally, HREF guidance indicates a 40-60% chance of
2+ inches of rain within a 6-hour period (mainly 6-12 PM),
roughly along the area of Hinesville to Savannah, and as far
north as Beaufort. Flood Advisories or Flash Flood Warnings
could eventually be needed later.

Tonight: The cold front is anticipated to shift a bit more south,
sinking closer toward the FL/GA border late, allowing stable high
pressure to gradually wedge southward into the forecast area.
Scattered shower and thunderstorm activity look to continue to
focus across extreme southeast Georgia with activity tapering
across southeast South Carolina. This lingering/prolonged
activity near the front could continue the flood threat into
tonight; therefore, Flood Advisories and/or Flash Flood Warnings
could extend into the early overnight period. Low temps will be
cooler than previous nights, generally dipping into the upper
60s/lower 70s inland to mid 70s along the immediate coast.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
High pressure will extend south into the region early next week,
while a stalled front lingers nearby offshore and to the south.
There are hints that the front could nudge back northward towards or
into the area on Tuesday. The mid levels will feature broad
troughing initially, before a ridge becomes more established over
the western Atlantic and places the forecast area in between these
two features. A series of shortwaves are forecast to rotate across
the area. Deep moisture will remain in place, noted by PWats of 2+
inches. This pattern will favor unsettled conditions through the
period with daily chances for showers and some thunderstorms. While
coverage will be highest during the daytime hours, precip could
occur overnight as well. Instability will be meager, precluding much
of a severe weather threat. The primary concern with any activity is
locally heavy rainfall. The highest risk for flooding overall looks
to be roughly Beaufort county and south across southeast Georgia,
but certainly issues could occur anywhere over the forecast area
when high amounts of rain falls in a short period of time.

After the extended stretch of hot and humid conditions last week, we
will now see unseasonably cool temperatures, especially Sunday and
Monday when highs largely peak in the upper 70s to lower 80s. These
values are several degrees below early August normals. Lows will
even fall into the mid/upper 60s over interior locations.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
Unsettled weather could continue into mid to late week as a stalled
front will still be meandering near/over the region and occasional
mid level disturbances pass through overhead. This in combination
with ample moisture will result in numerous showers and
thunderstorms each day. With potentially wet antecedent conditions,
locally heavy rainfall could pose a risk for flooding. Temperatures
moderate closer to normal, but still remain a touch below topping
out largely in the upper 80s.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
18Z TAF Discussion: A front currently positioned along the Altamaha
River will slowly sag southward toward the FL/GA border this
evening before stalling. Scattered to numerous showers and
thunderstorms are expected to develop by mid afternoon. The
greatest coverage of convection is expected across southeast
Georgia, generally near the front. Tempo MVFR/IFR cigs/vsbys are
possible with afternoon/evening showers and thunderstorms.
Prevailing -TSRA groups have been introduced during the early
evening hours at all terminals. A few storms mainly across
southeast Georgia, potentially which could impact KSAV, could
produce gusty winds and/or torrential rainfall that could
briefly reduce vsbys to 1 mile or less. These details could be
refined in the 00Z TAF issuance or handled by amendments as
trends ensue. Isolated to scattered showers could remain through
the night and into Sunday across southeast Georgia, while
tapering off to the north, therefore we maintained VCSH through
18Z Sunday. Otherwise, low (MVFR) cigs are expected to persist,
with potential for a period of IFR cigs late tonight.

Extended Aviation Forecast: Flight restrictions are possible in low
clouds and showers/thunderstorms through early next week as a
stalled front lingers in the vicinity.

&&

.MARINE...
Today and Tonight: A cold front will slowly drop southward
across the Georgia waters this afternoon and evening before
stalling. Winds will shift north-northeast behind the front,
generally peaking in the 10-15 kt range. Scattered to numerous
showers and thunderstorms are likely across the waters this
afternoon through most of the night, a few which could become
strong this evening, mainly across the Georgia waters closer to
the front. Later tonight as the pressure gradient tightens,
winds across the Charleston County nearshore waters (out to 20
nm) will slightly increase, approaching 20 kt. Gusts could also
approach 25 kt at times, but should solidly remain below Small
Craft Advisory criteria. Seas will range 2-3 ft today,
increasing to 3-5 ft across the Charleston County nearshore
waters late tonight.

Sunday through Thursday: High pressure will reside inland, while a
stalled front meanders nearby/over the coastal waters through much
of the upcoming week. An enhanced pressure gradient between these
two features will lead to gusty northeast winds early next week,
especially on Sunday. Conditions are forecast to stay below Small
Craft Advisory criteria, but some low 20 kt gusts are possible.
Northeast winds are forecast to persist into mid-late week with
speeds 15 knots or less. Seas will average 2-4 feet.

Rip Currents: Gusty northeast winds and increasing swells will lead
to a Moderate Risk of rip currents at the Charleston county beaches
on Sunday. Local calculations keep the remaining beaches at a Low
Risk.

&&

.CLIMATE...
Record Precipitation:

August 2:
KSAV: 1.81/1990

&&

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

&&

$$

NEAR TERM...BRS
SHORT TERM...ETM
LONG TERM...ETM
AVIATION...BRS/ETM
MARINE...BRS/ETM