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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCHS 111732
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1232 PM EST Tue Dec 11 2018

.SYNOPSIS...
High pressure will prevail through Thursday. A storm system
will affect the area Thursday night into Saturday morning,
followed by another area of high pressure.

&&

.NEAR TERM /THROUGH TONIGHT/...
No changes with this update as everything remains on track.

Rest of today: The sharp mid/upper level trough will continue
moving off the coast this afternoon, with northwest flow
prevailing as ridging builds eastward. At the surface, high
pressure along the Gulf Coast will gradually shift eastward.
Sunny skies are expected, allowing highs to reach the low to
mid 50s.

Tonight: Surface high pressure will draw closer and settle
across the Florida, Georgia, Alabama area by late tonight.
Clear skies should prevail until very late when a few cirrus
approach from the west. Expect a cold night with lows below
freezing for areas away from the immediate coast.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
Wednesday will be dry with high temps in the mid/upper 50s as
deep layered high pressure prevails. Temperatures will warm
several degrees by Thursday as the surface high shifts east and
southerly flow develops. A few showers will be possible along
the GA coast late in the day as an upper shortwave spurs a weak
coastal trough to develop off the GA coast.

A powerful closed upper low will move into the Arklatex region
late Thursday night, spreading a large area of vorticity energy
into the Southeast. Southerly 0-6 km flow will steadily
strengthen Thursday night and Friday, with the resultant theta-e
advection pushing PWats to 1.5-1.8" by midday Friday. Thursday
night should see a steady increase in rain shower coverage due
to strong isentropic ascent along and north of a warm front
bisecting the area W-E. We are showing widespread showers and a
few thunderstorms on Friday as several weak surface lows move
through the area ahead of a cold front Friday evening. Given the
unseasonably high PWats and deep forcing, many areas could pick
up 1-2" of rain by Friday evening.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Models have come into better agreement with the timing of the
cold front, now showing it moving offshore late Friday night.
Downslope flow will maintain high temps around 60 through Monday
before a reinforcing cold front brings some cooler weather by
Tuesday.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
18Z TAFs: VFR.

Extended Aviation Outlook: MVFR or lower conditions are likely
Thursday night through Friday night as a storm system affects
the area.

&&

.MARINE...
Today through tonight: High pressure will gradually draw closer
to the area today, and northwest flow will prevail. Wind speeds
will top out in the 15-20 knot range for the most part with
some gusts to 25 knots in the outer waters. Overnight, winds
will drop off a bit as the gradient weakens, becoming 10-15
knots. Seas will be 2-4 ft in the nearshore waters today, with
some 5 footers possible near the 20 nm line in the Charleston
County waters. Overnight, nearshore seas will be in the 1-3 ft
range. For the outer waters 4-6 ft seas will continue through
the evening dropping off to 3-5 ft late. The Small Craft
Advisory for the outer Georgia waters continues through
midnight.

Fairly quiet marine weather expected Tuesday through Thursday
as high pressure persists. Increasing southerly flow ahead of a
cold front Thursday night through Friday will likely require
Small Craft Advisories for most waters. Advisory conditions
likely to persist into Saturday night or Sunday behind the cold
front as fairly strong westerly winds occur.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until midnight EST tonight for AMZ374.

&&

$$
NEAR TERM...
SHORT TERM...
LONG TERM...JRL
AVIATION...
MARINE...