Savannah, Georgia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

473
FXUS62 KCHS 031554
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1054 AM EST Tue Dec 3 2024

.SYNOPSIS...
High pressure will prevail through mid week. A cold front will
push across the area Thursday, with the return of high pressure
thereafter.

&&

.NEAR TERM /THROUGH TONIGHT/...
Today: Aloft, a longwave trough will remain across the East CONUS
with its axis extending from the Northeast to Southeast United
States for much of the day. At the sfc, high pressure centered
across the Ozarks will shift east within a west-northwest flow,
crossing Kentucky/Tennessee through late day. Despite a dry
downslope wind and full day of sun, cold air advection associated
with the approaching arctic airmass will limit afternoon highs
some 15 degrees below normal locally. In general, high temps
should peak in the mid-upper 40s across northern/inland areas
to lower 50s across Southeast Georgia.

Tonight: The arctic high will push atop the immediate vicinity,
allowing for winds to quickly decouple, and resulting in light
or calm winds through the night. With clear skies and the
extremely dry air mass in place, excellent radiational cooling
will transpire. We`re looking at our coldest night so far this
season, with the main challenge to be how cold does it get.
While radiational cooling usually leads to colder than expected
for many places, 850 mb temperatures warm about 6-7C between 12Z
Tuesday and 12Z Wednesday. This coincides with a slight increase
in the low level thickness as well.

Most communities inland will already be below freezing by 9 or
10 PM, and remain there through mid morning on Wednesday. As
much as 11-12 hours of temperatures below 32F can occur. The
freezing line looks to make it to near the coast, with a hard
freeze just about everywhere inland from the Intra-Coastal. We
leaned toward the colder guidance, utilizing much of the NBM
50th Percentile. This will result in the coldest temperatures of
the season, with some places down near 20-21F across our northwest
tier of zones. This is near the criteria for a Cold Weather
Advisory. But since it looks marginal and DESI indicating very
little probability of such an occurrence, we opted to defer to
later shifts to see if the advisory will be necessary.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Surface high pressure centered over the Southeastern U.S. will
slide offshore Wednesday as a cold front approaches from the
west. Conditions will be rain-free and dry through Wednesday,
and even Thursday despite the frontal passage. The deeper
moisture looks to slide south of the area; however, there could
be a small chance an isolated shower brushes interior southeast
Georgia Thursday. Otherwise, a slight uptick in southwesterly
winds are expected ahead of the FROPA, with the greatest period
of WAA to occur Wednesday night into Thursday morning. Breezy
conditions are possible during this time and gusts across Lake
Moultrie could reach 25 kt or greater, which would warrant a
Lake Wind Advisory. Southwesterly winds and the eventual WAA
regime will allow for a brief warm-up Wednesday into Thursday.
Peak temperatures Wednesday will reach the low/mid 50s, with
upper 50s possible closer to the Altamaha River. Overnight lows
Wednesday will dip into the mid to upper 30s inland, and lower
40s along the coast. For Thursday, highs are forecast to warm
into the low to mid 60s.

The cold front should quickly push through early Thursday night,
with high pressure returning Friday. Overnight Thursday,
temperatures will plummet in the wake of the front ranging from the
upper 20s inland, low to mid 30s closer to the coast, and upper 30s
along the beaches. Friday will be rather cold, even under mostly
clear skies, with highs progged to reach the mid to upper 40s across
southeast South Carolina and upper 40s/lower 50s across southeast
Georgia.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A cold front associated with a shortwave could approach early next
week. Its approach could bring a bout of deeper moisture with
isolated showers initially Sunday into Monday, but a greater chance
of showers associated with the main low pressure center is
anticipated Monday into Tuesday. A significant warming trend will
occur during the period due to ridging across the Southeast. Peak
temperatures initially in the 50s will increase to near or around 70
degrees by Monday.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
VFR conditions will prevail at KCHS, KJZI, and KSAV through 12Z
Wednesday. In wake of a cold front, arctic high pressure will
build in, allowing for N and NW winds to get a bit gusty during
the day, peaking around 20 kt. Winds drop off considerably with
sunset, and go light or calm tonight.

Extended Aviation Outlook: VFR. Gusty conditions associated with a
cold front are possible at the terminals Thursday.

&&

.MARINE...
Today: An arctic high pressure system will build into the area
behind a cold front, accompanied by modest isallobaric pressure
rises, cold air advection, and a pinching of the gradient.
North/northwest winds will generally peak between 15-20 kt with some
gusts around 25 kt across the Charleston County waters into early
afternoon, and the Georgia waters 20-60 nm offshore through late
afternoon. Small Craft Advisories will continue for these coastal
zones as a result for the time being. Seas will be limited
somewhat by offshore wind trajectories, but should still range
between 2-4 ft across nearshore waters (largest of the Charleston
County Coast) and 3-5 ft across outer Georgia waters.

Tonight: All Small Craft Advisories will likely have ended by
sunset, and with the arctic high shifting into the Southeast, some
relaxation of the pressure gradient. However, the setup will still
favor northerly winds up to 15 or 20 kt early on, then dropping at
least 5 kt or so overnight. Charleston Harbor will experience much
lighter winds, mainly in the range of 5-10 kt. Seas will generally
range between 2-3 ft nearshore to 3-4 ft across outer Georgia waters.

Wednesday through Sunday: Surface high pressure across the Southeast
will prevail before a cold front pushes offshore Thursday night.
Light winds around 5-10 kt will shift out of the southwest Wednesday
evening with a surge expected overnight ahead of the aforementioned
front. Small Craft Advisories look likely for most marine zones
through Thursday/Thursday night with gusts around 25-30 kt. Elevated
winds will continue through Friday as high pressure rebuilds, before
settling over the weekend. Seas will average 2-4 ft Wednesday before
building Thursday to 3-5 ft with some 6 footers breaching the
Charleston County waters. Seas will then settle over the weekend,
back down to 2-4 feet.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 1 PM EST this afternoon for AMZ350.
     Small Craft Advisory until 5 PM EST this afternoon for AMZ374.

&&

$$

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