Savannah, Georgia Weather Forecast Discussion

059
FXUS62 KCHS 131824
AFDCHS
Area Forecast Discussion
National Weather Service Charleston SC
224 PM EDT Sat Sep 13 2025
.SYNOPSIS...
High pressure will extend across the region into next week.
Weak low pressure could develop offshore by Monday before
moving farther out into the Atlantic by mid next week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Satellite water vapor indicated a mid-level low off the coast of GA,
seen as notch in the moisture plume over the Atlantic waters. North
of the H5 low, a stream of cirrus clouds should remain across
the SC Lowcountry through the rest of the day and overnight. At
the sfc, the forecast area will remain between a sfc ridge
centered over the Foothills of the Carolinas and broad low
pressure over the Gulf Stream. This pattern will support
northeast winds around 10 mph through tonight. Given cool
thicknesses and thin cloud cover, min temperatures are forecast
to range from the upper 50s inland to the mid to upper 60s along
the coast.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
A sharp upper-level trough positioned along the Southeast U.S. coast
is expected to evolve into a closed upper-level low by Monday.
As the low becomes more defined, there is potential for surface
cyclogenesis to develop a weak non-tropical low off the South
Carolina coast, near an existing coastal trough. However, the exact
location and intensity of this surface low remain highly uncertain.
At the surface, a wedge of strengthening high pressure will remain
in place across the interior, keeping the best chances for
measurable rainfall well offshore.
Mostly sunny skies with a few clouds can be expected Sunday, though
a stray, low-topped shower cannot be entirely ruled out along the
extreme southeast Georgia coast. Otherwise, dry conditions will
dominate across the forecast area. Monday and Tuesday, the overall
forecast remains largely dependent on the evolution of any offshore
surface low. Although, a brief increase in mid and upper-level
moisture will bring slight rain chances to the South Carolina coast
on Monday. Even so, mostly sunny skies with just occasional cloud
cover are expected to continue across much of the area. PoPs range
from 20-30% east of I-95 Monday, mainly across the Charleston Tri-
County. Tuesday currently appears dry, with no mentionable rain
chances and continued mostly sunny conditions.
Temperatures will remain seasonable through Tuesday, with highs in
the low to mid 80s across most locations, and some upper 80s
possible across interior Southeast Georgia. Overnight lows will dip
into the low to mid 60s inland, with upper 60s closer to the
coast.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
Mostly quiet conditions will persist through the rest of the
upcoming week as the upper low across the Carolinas gradually
weakens and ejects out to the northeast Wednesday. The inland high
pressure wedge is forecast to strengthen as ridging builds in behind
the departing upper low. Any meaningful chance for measurable
rainfall will generally remain confined well offshore. Temperatures
will warm ever so slightly through the period, peaking in the upper
80s/lower 90s Thursday and Friday.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
18z TAFs: VFR. At the sfc, the terminals will remain between a
sfc ridge centered over the Foothills of the Carolinas and broad
low pressure over the Gulf Stream. This pattern will support
gusty northeast winds through the rest of this afternoon,
settling to 5 to 10 kts this evening and tonight. Northeast
winds may develop gusts into the teens by mid-morning Sunday.
Extended Aviation Forecast: There are no high confidence
concerns.
&&
.MARINE...
Tonight: The pressure gradient between an inland sfc ridge and a
trough over the Gulf Stream will support gusty NE winds across the
Atlantic waters tonight. This pattern should generally yield
northeast winds between 15 to 20 kts with gusts to 25 kts across the
Atlantic waters. The Charleston Harbor should see northeast winds
between 10 to 15 kts, with gusts to 20 kts through early this
evening. Seas this evening between 5 to 8 ft may decrease to 4 to 7
ft late tonight. Small Craft Advisories will remain in effect for
all Atlantic waters tonight.
Sunday through Thursday: Pinched gradient conditions between inland
high pressure and a coastal trough offshore look to hold through
much of the week. Weak low pressure could develop offshore late
Sunday or Monday, but its strength and track are uncertain. Any low
that forms could have a local impact, but to what degree remains
unknown. For now, northeast winds will remain around the threshold
for Small Craft Advisory conditions (25 kt) for all marine zones
except the Charleston Harbor Sunday into Monday. Additionally, 6+ ft
seas will persist into Monday where Small Craft Advisories continue,
gradually dropping Monday into Monday night. By mid-week conditions
should improve as general model consensus shows the weak surface low
lifting north/northeastward, away from the area.
Rip Currents: Gusty northeast winds Sunday will persist within
pinched gradient conditions. This coupled with 4-5 ft swells with an
8 second period will keep a continued high risk for rip currents
along the Georgia beaches and a moderate risk for the South Carolina
beaches. Headed into Monday, northeast winds will be slightly
elevated, and lingering swell will continue a moderate risk for rip
currents at all area beaches.
&&
.TIDES/COASTAL FLOODING...
Total water levels will remain elevated through the middle of next
from large tidal departures due to a pinched pressure gradient with
elevated northeast winds. The potential for coastal flooding will
continue though through the weekend, especially for coastal portions
of Charleston and Colleton Counties.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...High Risk for Rip Currents through Sunday evening for GAZ117-119-
     139-141.
SC...High Risk for Rip Currents until 8 PM EDT this evening for
     SCZ048>051.
     Coastal Flood Advisory until 3 PM EDT this afternoon for
     SCZ049-050.
MARINE...Small Craft Advisory until 8 PM EDT Monday for AMZ350-352.
     Small Craft Advisory until 2 AM EDT Monday for AMZ354.
     Small Craft Advisory until 8 PM EDT Tuesday for AMZ374.
&&
$$
NEAR TERM...NED
SHORT TERM...BRS
LONG TERM...BRS
AVIATION...BRS/NED
MARINE...BRS/NED

NWS CHS Office Area Forecast Discussion