Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

108
FXUS62 KCHS 071533
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1133 AM EDT Sat Jun 7 2025

.SYNOPSIS...
Active weather pattern continues as multiple frontal boundaries
impact the region. A few storms may become strong to severe
severe this weekend, with damaging winds expected to be the
primary hazard. A brief reprieve in heat then returns early
next week in the wake of a strong cold front.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, a mostly zonal flow will prevail across the Southeast
between broad troughing extending from the Midwest to the Northeast
and broad ridging extending across the Gulf and western Atlantic. At
the sfc, the local area will remain nestled between high pressure
extending westward from the Atlantic and lee troughing occurring
east of the Appalachians. The pattern will generally support a dry
westerly flow across the local area into mid afternoon with model
soundings supporting strong sfc heating under mostly sunny skies.
However, moderate instability will also develop in response to
strong sfc heating (MLCAPE ~2500-3000 J/kg), which could help
fuel a few showers and/or isolated thunderstorms closer to
coastal areas where convergence is greatest near a developing/pinned
sea breeze mid-late afternoon. Given DCAPE values approaching
1000 J/kg, a stronger thunderstorm will be capable of producing
gusty winds, and perhaps an isolated damaging wind prior to sunset.

Outside of shower/thunderstorms, the main impact from a westerly low-
lvl flow will be to support high temps in the low-mid 90s away from
the beaches. These temps along with sfc dewpts in the low 70s during
peak heating hours will support heat index values in the 101-106
range, falling just short of Heat Advisory criteria. Low-lvl mixing
should also support a somewhat breezy afternoon with 1000 mb
geostrophic winds between 30-35 kt supporting wind gusts up to 20
mph for most areas, and potentially upwards to 25 mph along the
Charleston County Coast near a pinned sea breeze.

This Evening and Overnight: It appears that the best chance for
convection will come during the evening hours and will be largely
dependent on upstream convection moving in from the west at some
point in the evening. Hi-res model data is quite mixed on the speed,
placement, and even existence of the upstream convective complex in
question and its potential to impact some or all of the forecast
area. At this point, current thinking is that a convective complex
will move across north and central GA in the late afternoon or early
evening hours and then push into the forecast area at some point in
the 7-9pm time period. Given the westerly flow aloft and the track
across north and central GA, it appears the area that stands the
best chance of seeing thunderstorms will be our southeast SC
counties. Despite the timing being after diurnal heating and into
the evening, the environment should be largely undisturbed. The
complex will likely be quite progressive thanks to ~30 knots of mid-
level flow. Model soundings also suggest DCAPE values of 1,000 J/kg
or higher, supporting a damaging wind gust threat with any
thunderstorms that move through. The area we think stands the best
chance to be impacted remains in the SPC Day 1 Slight Risk threat
area, primarily for the wind threat. Whatever does move through
during the evening should shift offshore and away from the coast
through the early morning hours. The rest of the overnight should be
dry and mild with temperatures falling into the low to mid 70s.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
Balmy conditions continue Sunday, with afternoon highs largely
in the lower 90s and dewpoints in the low to mid 70s. Thus,
similar to Saturday, expect heat indices to rise into the 90s to
lower 100s, with the warmest values remaining along and east of
I-95. As always, we encourage you to remain hydrated and to
take break indoors as needed.

In regard to precipitation, Sunday`s atmosphere and setup will
be largely conditional on how Saturday pans out. If convection
does reach our area, could see showers linger through daybreak,
which would put a slight damper on additional development later
that afternoon as the atmosphere works to stabilize itself.
However, if the convection fizzles out before reaching us
Saturday night, think there is a decent chance that our area
could see some strong to severe storms Sunday afternoon and
evening. In terms of dynamics, soundings still show ample CAPE
(upwards of 2000+ J/kg), DCAPE values between 500 to 1000 J/kg,
0-6 km shear around 35 kt, and steep low to mid level lapse
rates (7-8 degC/km). All this to say, IF storms do develop,
believe damaging winds (60+ mph) and hail to the size of
quarters or slightly larger would be possible. We encourage you
to remain weather ready and have multiple ways to receive
warnings!

Otherwise, look for upper level troughing across the Ohio River
Valley to deepen Monday as an upper level low builds over the
Great Lakes region. Sfc cold front ahead of this feature will
take aim at the region Monday afternoon, before stalling out
that evening. As a result, look for renewed chances for showers
and storms to return to the forecast. Expect the aforementioned
upper level trough to continue its journey eastward Tuesday,
pushing yet another sfc cold front toward the region. This will
allow us to see a brief reprieve from the heat, as afternoon
highs settle back into the mid to upper 80s. Lows during this
time will still remain quite mild though, as temperatures only
fall into the lower 70s.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
Upper level pattern shifts heading into Wednesday, with flow
becoming quasi-zonal ahead of modest ridging. Meanwhile, at the
sfc, will see a few frontal boundaries meander around the
region. As such, will likely see daily chances for diurnally
driven showers and storms continue, especially during the late
afternoon hours as the seabreeze pushes inland. Otherwise, look
for highs in the upper 80s to lower 90s to remain common, with
overnight lows generally in the lower 70s.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions should prevail for most of the 12z TAF period at
KCHS, KJZI, and KSAV. Winds will be westerly for much of the
day, with frequent gusts into the 17-20 knot range expected.
While there could be an isolated shower or thunderstorm nearby
in the afternoon, it appears the best chance for thunderstorms
will come during the evening hours and potentially into the
early morning hours. Model guidance remains quite uncertain,
but there is potential for clusters of storms to move in from
the west this evening. The best chances are at KCHS and KJZI,
and we have maintained VCTS between 02-06z.

Extended Aviation Outlook: Typical summertime convection
pattern will bring periodic flight restrictions through early
next week.

&&

.MARINE...
Today and Tonight: The gradient will tighten across the local
waters today, allowing for elevated southwest flow into the
15-20 kt range for much of the waters this afternoon and
evening. In fact, there could be a few 25 kt gusts across the
South Carolina waters as well as in Charleston Harbor. However,
conditions should fall just shy of Small Craft Advisory thresholds.
Seas should peak around 3 ft today, then build up to around 4 ft
this evening and overnight as winds increase.

Sunday through Tuesday: Expect west south-westerly winds to
prevail throughout the period, with sustained speeds between 10
to 20 kt. Winds could become a bit breezy at times, with gusts
up to 23 kt possible as the sea breeze moves inland. Otherwise,
look for seas to range between 2 to 4 ft throughout the period.

&&

.CLIMATE...
Record High Minimum Temperatures:

June 7:
KCHS: 75/2021
KCXM: 79/2021

June 8:
KCHS: 76/1980
KCXM: 78/2021
KSAV: 79/1881

June 9:
KCHS: 77/1978
KSAV: 77/1877

June 11:
KCHS: 76/2020
KSAV: 76/2010

&&

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

&&

$$

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