361
FXUS62 KCHS 030701
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
301 AM EDT Sun Aug 3 2025

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

&&

.NEAR TERM /THROUGH TONIGHT/...
Prior to daybreak: A weak wave of low pressure along a stationary
front east of the Savannah River Entrance offshore will continue to
play a role in northeast winds across nearby coastal waters
producing ample moisture convergence and the continuation of
showers/thunderstorms along coastal communities from Edisto Island,
SC to Savannah, GA. Instability plots continue to show a tongue
of higher MLCAPE just off the beaches along with PWATs near
2.25-2.40 also touching coastal communities, supporting higher
rainfall rates and a risk for flash flooding along the lower
South Carolina Coast. Flood Advisories and/or Flash Flood
Warnings could eventually be needed.

Today: A broad/weak mid-lvl trough will remain across the Midwest
and Northeast while subtle h5 vort energy traverses the Southeast
United States. At the sfc, high pressure nudging across the area
from the north will keep a nearly stationary front south of the
Altamaha River, while weak low pressure across coastal waters
departs further offshore. Shower and thunderstorm activity
associated with this feature should wane across coastal communities
this morning, but activity is likely to return during afternoon
hours as weak h5 vort energy traverses across ample moisture locally
(PWATs ~2.25 inches). The bulk of shower and thunderstorm activity
should remain across far Southern South Carolina and into Southeast
Georgia, closer to the front nearby, but instability will be notably
weaker than previous days, therefore limiting stronger thunderstorm
activity. The main concern will continue to be locally heavy
rainfall with shower/thunderstorm activity, with coastal areas along
and south of Beaufort, SC into Southeast Georgia seeing the higher
potential for Flash Flooding. WPC continues to highlight much of the
area in a Slight Risk for excessive rainfall. Flood Advisories
and/or Flash Flood Warnings could eventually be needed. Given the
extent of shower/thunderstorm activity and high pressure building
into the region, high temps should range in the upper 70s/around 80
well inland to low-mid 80s across the remainder of the area.

Tonight: Much like the previous night, shower and thunderstorm
activity could linger into evening hours, but should gradually wane
with the loss of diurnal heating while sfc high pressure is in place
and the front remains stalled south of the local area. Given the
moist environment, few to scattered showers/thunderstorms can not be
ruled out overnight and remain in the forecast, but the bulk of
heavier rainfall concerns should be south of the local area and/or
offshore after midnight. Low temps should dip into the upper 60s
inland to low-mid 70s closer to the coast.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
The work week will start off with a surface high pressure across the
northeast, a stalled front off to our south extending northeastwards
into a weak surface low pressure, and broad mid-level troughing
across the south-central CONUS. This will continue our pattern
that we`ve been in, resulting in chances for scattered showers
and thunderstorms throughout the day, with afternoon highs in
the upper 70s to lower 80s across inland SE SC and SE GA, to
lower to mid 80s along the coast. With precipitable water values
remaining just above 2 inches, locally heavy rainfall remains
the main concern as the stronger showers/thunderstorms will be
capable of putting down 2-3 inches of rain in an hour, which has
been observed over the past few days. Flood advisories and
flash flood warnings may be needed as a result, especially for
areas where flooding rains have already been experienced
recently. WPC maintains a marginal risk (level 1 out of 4) of
excessive rainfall, which seems appropriate given the
isolated/scattered nature of the possible flooding. A few of the
high resolution convection allowing models (CAMs) are
indicating an MCS lifting northwards out of southern Georgia
Monday afternoon/evening, limited by the lack of instability
north of the front, so that`ll be something to monitor model
trends for.

Tuesday and Wednesday will see the aforementioned mid-level trough
continue to slowly shift eastwards, with the front remaining even
further off to our south. This will continue our unsettled pattern
for a few more days, with temperatures rising to near normal in the
upper 80s across the region. A few of the models have started to
indicate the previously mentioned surface low over the Atlantic
water may become tropical, further made evident by NHC`s tropical
weather outlook, though that looks to move out to sea.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
Ridging attempts to build back across the region as a narrowing
trough moves out of the south-central US and towards the east
coast into the end of 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 deep moisture still in place, with shortwave energy and
sea-breezes as forcing mechanisms. Seasonal temperatures in the
upper 80s to lower 90s are expected.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
KCHS/KJZI: VFR conditions should prevail into daybreak, but tempo
MVFR cigs are possible at times, particularly at JZI as showers
attempt to reach the terminal during the night. Tempo MVFR
conditions at possible at both terminals after daybreak into late
morning hours. Confidence is then quite low in regards to flight
restrictions associated with shower/thunderstorm impacts at both
terminals this afternoon, but VFR conditions should prevail for a
bulk of the time period. Adjustments will likely be needed to
overall timing and impacts of convection during the afternoon.

KSAV: An area of low pressure off the coast should continue to
produce showers near the terminal for the next few hours and
possibly into daybreak. Regardless of convection, IFR cigs are
expected for a bulk of the night, persisting into mid-late morning
hours. Additional rounds of showers and thunderstorms are more
likely to occur during the afternoon into early evening, thus have
maintained MVFR conditions with -SHRA and VCTS from 16Z Sunday to
01Z Monday. Adjustments will likely be needed to overall timing and
impacts of convection during the afternoon.

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...
Early Morning: A tighter pressure gradient associated with high
pressure nudging into the area north of a front offshore should
support gusty north-northeast winds (15-20 kt) across South Carolina
waters prior to daybreak and the potential for a few wind gusts up
to 25 kt across Charleston County waters (out to 20 nm) during the
next few hours. Given winds should gradually trend weaker and the
duration/coverage of 25 kt wind gusts being rather small, conditions
do not support a Small Craft Advisory at this time. Seas will build
in response to favorable northeasterly winds, generally to 3-5 ft
across Charleston County waters, and 2-3 ft across southern South
Carolina and Georgia coastal waters.

Today and Tonight: A modest pressure gradient will reside across
local waters between high pressure inland and a nearby front stalled
along or just south of local waters. Weak areas of low pressure
could also develop along/near the front, spawning gusty showers and
thunderstorms for much of the period. Outside of convection, north-
northeast sfc winds will generally range between 15-20 kt during the
day, strongest across South Carolina waters. The pressure gradient
should then weaken during the night, supporting northeast winds in
more of the 10-15 kt range. Seas will slowly build across the waters
within the northeasterly flow, generally to 3-5 ft (largest off the
Charleston County Coast and outer Georgia waters).

Monday through Friday: 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 the continuation of gusty northeast winds
on Monday. Though conditions are forecast to stay below Small Craft
Advisory criteria, some low 20 kt gusts are possible on Monday.
Northeast winds are forecast to persist into mid-late week with
speeds 15 knots or less. Seas will average 2-4 feet.

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

&&

.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