744
FXUS62 KCHS 150034
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
834 PM EDT Sat Jun 14 2025

.SYNOPSIS...
Atlantic high pressure will build across the Southeast United
States through the weekend into next week.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Early Evening and Overnight: Weak mid-lvl energy rounding the
southeastern most edge of a trough positioned across the Ohio River
Valley will continue to support scattered/numerous showers along
with a few thunderstorms locally within highly moist and mild
conditions early evening, but will display a weakening/waning trend
due to a lack of environmental shear, loss of diurnal heating, and
worked over environment from previous convection throughout the day.
A bulk of guidance suggests all areas to become precip-free by
midnight, and remain dry through the remainder of the night. Light
southerly winds and some clouds will maintain mild/warm conditions
overnight along the northeast edge of the Atlantic ridge. In
general, lows should range in the low-mid 70s inland to around 80 at
the beaches and Downtown Charleston.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Afternoon showers and thunderstorms are in the forecast for
each successive day in the short term as South Carolina and
Georgia remain on the periphery of a mid-level ridge. Further
west over the ArkLaTex, a mid level weakness will start to break
off from the main flow with mid-level ridging remaining
centered over northwest Mexico and east of Florida. The weakness
will remain close enough to allow for daily afternoon showers
and thunderstorms. Usually when this type of synoptic setup
occurs, convective initiation occurs sooner than pure
climatology (12 - 2 PM instead of a 2 - 4 PM start time). Mean
cloud layer flow on Sunday and Monday is mostly 15 kt or less,
so the probability for any severe weather is forecast to remain
<5%. On Tuesday, mean cloud layer flow does tick up to around 20
kt, but this still will keep severe probabilities below 5%. The
main threat with this type of setup will be for locally heavy
rainfall as mean flow is weak with PWATs around 2.00". Expect
high temperatures to be near 90 degrees F each day with lows in
the mid 70s. Head index values are forecast to reach around 100
degrees F each day.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Not much change in the sensible weather Tuesday night through
Saturday. The pattern continues to support daily chances for
showers and thunderstorms with high temperatures slightly
warmer, or in the low 90s. Heat indices will remain below Heat
Advisory criteria of 108 degrees F, but will still be in the
103-107 degrees F range.

Taking a look at the cluster analysis, also supports the above.
Interestingly, the latest run of the deterministic GFS shows a
mid- level low breaking off over New England by the end of the
long term with a back door front possibly sliding through South
Carolina. However, the cluster analysis shows little in the way
of ensemble support for this with around 9% of the overall
ensemble solution space (GEFS, GEPS, EPS) with some variant of
this answer, while the other ~91% of the ensemble space showing
a much less amplified mid- level low.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
Early evening showers are expected to wane and/or shift offshore by
around 02-03Z, with the exception of showers and perhaps a
thunderstorm lingering at the SAV until around 01Z this evening.
TEMPO MVFR conditions are possible between 00-01Z at SAV due to
showers/thunderstorms. Otherwise, expect VFR conditions to prevail
at all terminals through at least 14-16Z Sunday. Showers and
thunderstorms return at all terminals early Sunday afternoon,
leading to VCTS at all sites in the current TAF issuance. TEMPO
flight restrictions will likely be required between the 18Z Sunday
to 00Z Monday time frame at all terminals, but will need to be
introduced in later TAF issuances as probabilities increase and
higher confidence in timing occurs.

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

&&

.MARINE...
Tonight: Convection ongoing across local waters should wane early
evening, although there is a secondary cluster of thunderstorms
approaching southern Georgia waters during the next 1-2 hours. Much
of this activity should weaken before entering local waters as well
given a worked over environment. Nevertheless, a few Marine Weather
Statements are possible across southern Georgia waters should
activity remain somewhat organized early this evening. Otherwise,
the local area will remain positioned between an Atlantic ridge to
the east-southeast and a trough approaching the central and southern
Appalachian Mountains late night. The pattern supports conditions
below Small Craft Advisory levels through the night, with south to
southwest winds generally around 15 kt and seas ranging between
2-4 ft.

Sunday through Thursday: Typical summertime conditions will
prevail over the waters with high pressure centered offshore of
the Southeast United 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: Swell will begin to increase in period to around
9s on Sunday with a southwest wind around 10 to 15 kt. This will
continue into Monday allowing a moderate risk of rip currents
to persist at all area beaches through Monday.

&&

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

&&

$$

NEAR TERM...DPB
SHORT TERM...
LONG TERM...
AVIATION...DPB
MARINE...DPB