980
FXUS62 KCHS 141315
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
915 AM EDT Sat Jun 14 2025

.SYNOPSIS...
Atlantic high pressure will build across the Southeast U.S.
through the weekend into next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
This Afternoon: Only minor changes were needed for the mid-
morning update, mainly to refine the timing and areal extent of
pops from late morning through mid-evening.

The region will remain situated between subtropical high
pressure centered well offshore of the Southeast U.S. and a
broad weakness over the lower Mississippi Valley. The airmass
across the region remains warm and humid with surface dewpoints
in the 70s and PWATs within a tenth of an inch of 2.0 inches.
12z composite theta-e analysis showed a sliver of dry air along
and east of I-95 with some modest 850 hPa theta-e pooling noted
west of there. Near term guidance keeps this corridor of dry air
over the coastal counties through early afternoon, which may
help delay convective initiation at the coast and near the sea
breeze until after 2 PM. Farther inland, convection should
begin to fire by noon with activity gradually focusing closer to
the coast as the afternoon progresses and convective outflows
are generated. Hourly pops were adjusted slightly to reflect
this idea, but net pops 50-70% were mostly maintained. A few
strong to marginally severe tstms will be possible through early
evening with weak shear in place. Gusty winds, cloud to ground
lightning and locally heavy rainfall will be the primary
hazards. The risk for an isolated severe tstm will be highest
near mesoscale boundary collisions.

Tonight: Convection should reduce in coverage after sunset.
However, isolated showers may linger through at least midnight,
with weak upper forcing and ample moisture/instability. Lows in
the lower to mid 70s inland, and the mid to upper 70s closer to
the coast.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
Daily chances for showers and thunderstorms continue as the surface
Atlantic high pressure remains off to our east, and an upper level
high is parked off to our south-southeast. While this won`t lead to
constant rain, highest probabilities and spatial coverage for rain
are expected through the late morning and into the afternoon hours
as instability builds, with chances decreasing into the overnight
hours as instability wanes. While severe weather can`t be entirely
ruled out given 1-2 J of MUCAPE, the lack of strong forcing and
weak mid-upper level flow will keep such activity isolated at
best. This is further validated by various AI/ML models, as well
as the SPC keeping chances for severe weather below 5%. With
precipitable water remaining above 1.75", locally heavy rainfall
can`t be ruled out.

As for temperatures, they are expected to slowly increase into the
beginning of the week given the persistent pattern underneath the
aforementioned upper level high. Both the NAEFs and ECMWF ensemble
situational awareness tables (ESATs) continue to show the region
remaining near/above the 90th percentile of climatology with respect
to geopotential heights from 850mb up to 200 mb per the NAEFS and
ECMWF, resulting in afternoon highs on Sunday in the upper 80s to
lower 90s and lower to mid 90s on Monday and Tuesday, while those
near the coast remain in the mid/upper 80s. Heat index values in the
mid 90s to lower 100s are also expected, possibly as high as mid
100s on Monday and Tuesday if dewpoints rise into the upper 70s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
The aforementioned pattern continues while the upper level ridge
begins to slowly build westward as a weak trough moves into the
northeast Thursday into Friday. Daily chances for showers and
thunderstorms continue, with temperatures remaining in the lower to
mid 90s. Currently have heat indices largely remaining below Heat
Advisory criteria of 108 degrees F, but that will need to be
closely monitored.

&&

.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
12Z TAFs: VFR are expected to prevail all sites through this
morning. By afternoon, scattered to numerous showers and
thunderstorms could produce periodic MVFR CIGs. Wind gusts
around 20 knots possible from late morning into mid afternoon.
Convection is expected to decrease in coverage after sunset this
evening, with a return to VFR conditions generally after 01z.

Extended Aviation Forecast: Brief flight restrictions are possible
in showers and thunderstorms each day, mainly in the afternoon.

&&

.MARINE...
Today through Tonight: No significant changes were made with
the early morning update. Although winds will gust to near 20
knots today, winds/seas are not expected to reach SCA levels
during this period. Deep layer high pressure will remain
southeast of the waters with deep layer troughing well
inland/west of the waters. This will keep south-southwest winds
of 10-15 knots in place, gusting to near 20 knots during the
afternoon as the seabreeze develops, but likely stays close to
the coast. Seas generally 2-3 feet within 10 nm of the coast,
and 3 to 4 feet beyond 10 nm.

Sunday through Thursday: Typical summertime conditions will prevail
over the waters with high pressure centered offshore of the
Southeast States. A broad, southerly wind regime can be expected
with winds generally averaging 15 kt or less, except a bit higher
along the land/sea interface and Charleston Harbor each afternoon
with the sea breeze. Seas will remain 4 ft or less through the
period.

Rip Currents: An easterly swell surge will arrive along the
Charleston County beaches today and all remaining beaches for
Sunday. This coupled with locally breezy conditions near the
afternoon sea breeze will support a moderate rip current risk for
the Charleston County beaches Saturday and for all beaches
Sunday.

&&

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

&&

$$