Charleston, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

112
FXUS62 KCHS 212058
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
358 PM EST Thu Nov 21 2024

.SYNOPSIS...
Canadian high pressure will build across the area tonight and
will remain the primary feature through early next week. A cold
front could approach the area towards the middle of next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Gusty winds peak this afternoon ahead of the approaching
reinforcing cold front, with 20-25 kt gusts continuing through
sunset. High pressure building in behind the front and a modest
surface inversion will result in weakening winds overnight,
with breezy conditions still near the water. Lows will dip into
the mid to upper 30s inland and lot to mid 40s along the coast.
Although the gradient will steadily diminish overnight, at least
light winds are expected to persist through sunrise, with HREF
probs of 10 m temps less than 35 and winds less than 5 mph
intersecting south of the Pee Dee region near 0%, negating any
tangible concern for frost.

Lake Winds: Winds peak on the lake through late afternoon, with
gusts as strong as 30 kt possible near the center of the lake.
The gradient will weaken behind a backdoor front that will cross
the lake early this evening, allowing the Lake Wind Advisory to
end, though gusts to around 20 kt will persist into Friday.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Deep mid level low will meander over the Northeast on Friday,
before exiting on Saturday. The pattern will then flatten and be
replaced by weak ridging by the end of the weekend. At the
surface, low pressure will finally exit allowing high pressure
to continue to build over the local area. Gusty winds are
expected on Friday, then the pressure gradient eases through the
weekend. Gusts over Lake Moultrie could approach Lake Wind
Advisory criteria Friday into Friday night, but at this point
remains just shy.

Otherwise, expect full sunshine with moderating temperatures.
It will be coolest on Friday when highs top out in the mid to
upper 50s (~10 degrees below climo). By Sunday, temperatures
will recover to the upper 60s. Lows will be chilly, falling
solidly into the 30s inland of the coast. Attention then turns
to the potential for frost over far interior areas. For Friday
night/Saturday morning, while temps are supportive, winds could
stay too elevated for widespread frost development. Certainly
not out of the question to see patchy frost in more sheltered
locations. For Saturday night/Sunday morning, we did go on the
cooler side of guidance with ideal radiational cooling
conditions in place. As winds are expected to go calm, this
could lead to a higher threat for frost. Will continue to
monitor trends.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Surface high pressure will continue to extend into the area
early next week, although a cold front could approach during the
latter half of the period. Still some uncertainties in the
evolution of that feature, whether it actually passes through or
stalls, so changes to the forecast are likely. At this point,
no rain is in the forecast. Temperatures will be above climo for
Monday and Tuesday then possibly cooler for Wednesday if fropa
occurs.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
High confidence VFR conditions through the period with very
limited moisture at any level. Gusty SW to W winds this
afternoon, with peak gusts likely around 25 mph, but frequent
gusts more in the 20-25 mph range. Gusts diminish this evening
as the surface inversion sets up away from the water (CHS and
SAV), which at least occasional gusts could persist at JZI into
the night as CAA continues to mix and funnel down the nearby
Stono River.

Extended Aviation Outlook: VFR. Gusty west winds are expected
again Friday.

&&

.MARINE...
The gradient continues to pinch ahead of a backdoor cold front
that will cross the waters early-to-mid evening. Still breezy W
winds overnight with the SCAs remaining in effect for all
waters. Minimal swell arriving, so seas largely dictate by local
offshore wind, 2-4 ft nearshore, up to 7 ft offshore.

Friday through Tuesday: Gusty west winds will persist over the
coastal waters Friday into Friday night, maintaining the ongoing
Small Craft Advisories. For the Charleston Harbor, gusts should
fall below 25 kt Friday evening so the Advisory is scheduled to
come down at 23z/6 PM. Conditions will improve on Saturday,
with winds and seas remaining below advisory levels through
Tuesday. Winds eventually turn southwest with speeds generally
15 knots or less and seas 1-3 ft.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Lake Wind Advisory until 11 PM EST this evening for SCZ045.
MARINE...Small Craft Advisory until 6 PM EST Friday for AMZ330.
     Small Craft Advisory until 7 AM EST Saturday for AMZ350-352-
     354.
     Small Craft Advisory until 10 AM EST Saturday for AMZ374.

&&

$$

NEAR TERM...CEB
SHORT TERM...Adam
LONG TERM...Adam
AVIATION...Adam/CEB
MARINE...Adam/CEB