091
FXUS62 KCHS 191929
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
329 PM EDT Thu Sep 19 2024

.SYNOPSIS...
An area of high pressure is expected to gradually strengthen
across the region through early next week. A weak cold front
may approach from the west by next Thursday.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Mid level trough axis will continue to extend down the Southeast
coast through tonight. Weak high pressure will prevail at the
surface. Any lingering shower activity will dissipate this evening
with loss of heating, leaving dry conditions for the remainder of
the overnight. There are signals that fog could once again develop
late towards daybreak, especially over southeast Georgia. Opted to
include patchy fog in the forecast in those locations. Low
temperatures will be near normal, ranging from the mid 60s far
inland to upper 60s/around 70 closer to the coast.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
Friday: The axis of the mid-level trough is expected to push east
over the western Atlantic as strong ridge centered over TX ridges NE
over the Ohio River Valley. GFS indicates that a short wave is
expected to track from north to south across the forecast area
during the afternoon, followed by rising heights. As temperatures
reach the mid to upper 80s over dewpoints in the 70s, weak
instability should develop across extreme SE GA. Latest run of the
HREF indicates that a weak sea breeze may develop along the GA coast
Friday afternoon. The combination of the shortwave passage, weak sea
breeze, and limited instability may support isolated showers along
the coast of SE GA during the afternoon.

Saturday and Sunday, the forecast area will become dominated by weak
sfc high pressure as a large H5 ridge builds across the Deep South
and Southeast U.S. GFS forecast soundings indicate that the
environment will remain less than 1.6 inches of PW with a
significant inversion at H8. High temperatures should favor values
in the upper 80s, with low 90s possible across inland GA on Sunday.
PoPs will remain less than SCHC through this weekend.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Monday through Tuesday, long term guidance indicates that the H5 590
DM ridge will shift east across the northern Gulf coast and FL. This
ridge combined with a low over the western Caribbean could set up a
Rex Block through early next week. H5 heights should increase across
the forecast area, peaking Monday and Monday night, limiting any
instability across the forecast area on Monday and Tuesday. The
forecast will feature dry weather through early next week. High
temperatures are forecast to remain in the mid to upper 80s.

Wednesday, H5 heights will begin to break down, possibly with the
approach of amplifying wave. GFS shows a cold front accelerating
east, possibly pushing across the forecast area by Wednesday
evening. The forecast will feature SCHC to CHC PoPs for showers and
thunderstorms. High temperatures will generally range in the mid
80s.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
Prevailing VFR conditions today. A brief shower is possible
this afternoon, but impacts in the way of flight restrictions
should be minimal if one occurs.

There is a chance for restrictions in fog late tonight towards
daybreak, with the best chances at KSAV. Maintained MVFR for
now.

Extended Aviation Outlook: VFR. No significant weather expected.

&&

.MARINE...
Easterly winds late the afternoon and evening will become
northerly late tonight. Winds generally remain 10 knots or less
with seas averaging 1 to 3 feet.

Friday through Monday: Building high pressure should result in winds
between 10-15 kts with gusts around 20 kts. Wave heights should
generally remain between 2-5 ft. Conditions should remain below
Small Craft Advisory criteria.

&&

.TIDES/COASTAL FLOODING...
Given high astronomical tides and latest tidal departures, minor
coastal flooding is expected along the Charleston and Colleton
county coasts with the evening high tide cycle. A Coastal Flood
Advisory has been issued with tide levels expected to peak between
7.3-7.5 ft MLLW. Further south and along the Georgia coast, current
forecast keeps tides from reaching minor flooding criteria of 9.5
ft MLLW in Fort Pulaski, but will continue to monitor trends.

Positive tidal anomalies along with high astronomical tides from the
full moon will lead to elevated tides for the rest of this week and
through the weekend. Coastal Flood Advisories will probably be
needed for both the morning and evening high tides through Friday
for both Charleston Harbor and Fort Pulaski.

The astronomical high tides start to lower Saturday and Sunday, but
the morning high tides will likely be elevated enough to still
require Coastal Flood Advisories (especially for Charleston and
coastal Colleton Counties). More uncertainty exists for Fort
Pulaski.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...Coastal Flood Advisory from 8 PM this evening to midnight EDT
     tonight for SCZ049-050.
MARINE...None.

&&

$$

NEAR TERM...ETM
SHORT TERM...NED
LONG TERM...NED
AVIATION...ETM/NED
MARINE...ETM/NED