354
FXUS62 KCHS 100026
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
826 PM EDT Wed Jul 9 2025

.SYNOPSIS...
Weak high pressure will extend across the area through the
weekend.

&&

.NEAR TERM /THROUGH THURSDAY/...
So far this evening, convection has developed along and behind a
large outflow boundary, sourced from thunderstorms over SE GA
this afternoon. This boundary has push north across the entire
forecast area, expected to slide across the adjacent Atlantic
waters through the rest of this evening. The strongest
convection should remain near the boundary this evening. In its
wake, stratiform rain will continue into the late evening
hours, gradually dissipating. The widespread rain has cooled
temperatures well into the 70s this evening. Temperatures may
remain nearly stationary through the rest of the night. The
forecast will feature adjustments to PoP/Wx and align hourly
temperatures to recent observations.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
Aloft, a large-scale ridge centered across the Atlantic will weaken
across the Southeast as h5 vort energy associated with a shortwave
tracks across the Tennessee Valley towards the Mid-Atlantic states.
At the sfc, the local area will remain nestled along the western
edge of an Atlantic high while troughing develops inland each day.
Although wind shear remains weak, there will be a small uptick in
low-lvl wind fields to support slightly more storm organization, but
also slightly faster storm motion, suggesting a greater threat for
strong and/or severe thunderstorms during the next few days, but
perhaps a more limited concern for minor flooding, although daily
PWATs around 2.0 inches should support brief heavy downpours with
convective activity each afternoon/evening.

Coverage of showers/thunderstorms should be greatest Thursday and
Friday (scattered to numerous), when peak h5 vort energy is draped
across a moderately unstable airmass residing near sfc troughing and
eventually an interacting sea breeze, although a more limited
isolated strong/severe thunderstorm risk could carry into the
weekend on Saturday with a noticeable downward trend in overall
convective coverage. Strong sfc heating supporting SBCAPE around
2000-3000 J/kg, low-lvl lapse rates between -7.5 to -8.5 C/km and
modest levels of DCAPE favor a damaging wind threat with
strong/severe thunderstorms Thursday afternoon/evening, and perhaps
again on Friday, with a lessor risk for small hail both days given
warm profiles/weak mid-lvl lapse rates. The latest SPC Day 2
Convective Outlook includes a Slight Risk for severe weather across
parts of Southeast South Carolina and Southeast Georgia on Thursday,
with a Marginal Risk for severe weather over remaining areas,
including the coast. WPC has also placed a Marginal Risk for
excessive rainfall across the far interior Thursday. On Friday, the
SPC Day 3 Outlook indicates a Marginal Risk for severe weather
covering far inland areas of Southeast South Carolina.

High temperatures will reach the upper 80s near the beaches to low-
mid 90s inland Thursday, then warm 1-2 degrees higher during the
weekend. A few spots could approach the upper 90s Saturday.
Overnight lows will remain mild, generally in the low-mid 70s inland
to upper 70s/around 80 at the beaches.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Ridging will continue to build over the Deep South late this weekend
and into early next week. Otherwise, little change expected in the
overall synoptic pattern and the forecast. Typical diurnal
convection will continue with scattered showers/thunderstorms
forming each day in the afternoon/evening. Sunday will be rather hot
as highs in the mid 90s could approach the upper 90s in some areas.
Heat indices could make a run for Heat Advisory criteria (108
degrees) in some spots, thus we will continue to monitor in the
event advisories are needed. Thereafter, temperatures will still
remain above normal, but highs will settle back into the lower
90s.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Prior to the 0Z TAFs, a large outflow boundary with scattered
showers and thunderstorms was pushing over the KCHS and KJZI
terminals. In the wake of the boundary, stratiform rain and
showers was lingering across SE GA and SC, including KSAV. The
light rain may remain over the terminals into the late evening
hours before dissipating. The rest of the night is forecast to
remain VFR with SW winds between 5 to 10 kts. On Thursday, sea
breeze thunderstorms are forecast across the terminals between
17-20Z, highlighted with TEMPOs for each TAF.

Extended Aviation Outlook: Periods and/or TEMPO flight restrictions
are likely at CHS/JZI/SAV terminals Thursday/Friday afternoons and
evenings due to showers/thunderstorms impacting the area. Precip
coverage should become more typical Saturday/Sunday, posing a more
limited risk for TEMPO flight restrictions each day.

&&

.MARINE...
Through Tonight: Southerly winds continue to prevail, with some
slight backing noting as the sea breeze moves inland. Speeds will
generally range from 10-15 kt, but will be closer to 15 kt with
gusts to 20 kt near the land/sea interface and Charleston Harbor
near and behind the sea breeze. Otherwise, look for winds to shift
more southwesterly overnight, with seas averaging between 2-3 ft. As
noted previously, deep summertime nocturnal surging may cause winds
to become slightly stronger than forecast - though no headlines are
anticipated at this time.

Wednesday through Sunday: A fairly typical summertime pattern will
remain in place for much of the week with Atlantic high pressure
centered offshore and a weak trough developing inland each day.
Relatively benign conditions are expected across local waters as a
result, with south to southwest winds around 15 kt and seas between
2-4 ft through late week, subsiding to 1-3 ft by early next week. A
few gusts up to 20 kt are possible along the Charleston County Coast
and in the Charleston Harbor due to sea breeze influences.

&&

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

&&

$$

NEAR TERM...NED
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...NED
MARINE...DPB/SST