Area Forecast Discussion
Issued by NWS Charleston, SC

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723
FXUS62 KCHS 021904
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
304 PM EDT Wed Jul 2 2025

.SYNOPSIS...
A cold front is expected to move into the area today and could
then linger along or just off the coast through the weekend.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
As of mid afternoon, visible satellite and sfc observations
indicated that a sea breeze was advancing inland across the coastal
counties as a cold front was pushing from the Carolina Foothills.
SPC mesoanalysis indicated a band of 2 to 2.1 inches between the sea
breeze and cold front. In addition, SBCAPE values between the two
boundaries is expected to build between 2500-3000 J/kg late this
afternoon and evening. High resolution guidance indicates that
clusters of thunderstorms will initial develop near the sea breeze
this afternoon, then coverage should increase as the cold front
nears from the west. These storms are forecast to have slow motions,
generally remaining around 10 mph, or propagate on outflow
boundaries. Given the deep moisture and slow storm motions, heavy
rainfall will be a concern for these storms. In fact, the 12Z HREF
indicate high probabilities for 3"/3hr to 10-30% with 1"/3hr
increasing to 50-70%. Flooding of low-lying areas or other poor
drainage areas will remain a concern through this afternoon into
early this evening, especially along the I-95 corridor.

Deep convection across SE GA/SC should dissipate late this evening,
some shower activity may linger over the adjacent Atlantic waters
late tonight. Low temperatures are forecast to range from near 70
inland to the mid to upper 70s along the coast.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
The surface front is expected to remain stalled along the coast
on Thursday. Weak shortwave energy will be moving off the coast
in the morning, with mainly weak NVA over the area. PWs will
remain fairly high, particularly along the coast, with slightly
drier air moving into inland areas. Close to 2000 J/kg CAPE
expected to develop during the afternoon with highs in the low
90s and dewpoints in the mid 70s. Scattered showers and tstms
expected to develop in the afternoon with the greatest coverage
closer to the coast mid to late afternoon. Quite a bit of
coverage could continue into the early to mid evening including
locally heavy rainfall and numerous cloud to ground lightning
strikes.

Slightly drier air will overspread the area on Friday with the
surface front a bit farther off the coast. However, there should
still be a moderate sea breeze in the afternoon and enough
instability to support scattered showers and thunderstorms,
mainly in the afternoon/evening.

Slightly drier high pressure will move into inland SC on
Saturday. However, a potential tropical or subtropical low may
develop well off the SC/GA coast and start moving northwest.
This could bring increasing coverage of showers and tstms to
coastal areas later in the day though the confidence is very low
due to large model uncertainties.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
The main concern for this period continues to be the possibility
that low pressure will develop off the SC/GA coast and then move
NW or N toward the area. NHC currently has a 40% chance for
tropical cyclone formation in the next 7 days. The 12Z GFS and
ECMWF are showing increasing chances of development. Even if
tropical development doesn`t occur, Saturday night through
Sunday could be relatively wet, particularly along the coast.

Upper ridging heading into the middle of next week should bring
increasing temperatures and heat indices.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
18Z TAFs: Clusters of thunderstorms will initial develop near
the sea breeze this afternoon, then coverage should increase as
the cold front nears from the west. These storms are forecast to
have slow motions, generally remaining around 10 mph, or
propagate on outflow boundaries. KCHS and KSAV TAFs will feature
TEMPOs from 19-23Z for TSRA. Convection should decrease as it
crosses west of the sea breeze later this evening. The rest of
the night should feature VFR conditions and south winds between
5 to 10 kts.

Extended Aviation Outlook: Brief flight restrictions will be
possible with isolated to scattered afternoon showers and
thunderstorms through the weekend and into early next week.


&&

.MARINE...
Tonight, the sfc pattern should yield southerly winds generally
between 10-15 kts. This evening, a slight gradient pinch may yield a
period of gusts around 20 kts late this evening. Seas are forecast
to range between 2 to 3 ft.

Winds/seas expected to remain below advisory criteria Thursday
through Sunday. The only caveat is the possibility of a
tropical or subtropical low developing off the GA/SC coast on
Saturday that could affect the waters Saturday night into
Sunday.

&&

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

&&

$$

NEAR TERM...NED
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...JRL
MARINE...JRL