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538
FXUS62 KCHS 282003
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
403 PM EDT Tue May 28 2024

.SYNOPSIS...
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A cold front will shift offshore tonight. High pressure will
build in from the west mid to late week, passing overhead and
then offshore over the weekend.
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&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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Through Sunset: Surface observations and satellite imagery
indicate a front has stalled along our coast. This is indicated
by W to NW winds far inland and dew points dropping into the
lower 60s. Additionally, there`s a weak sea breeze. However,
it`s pinned along the coast due to the W to NW surface winds.
The HRRR continues to indicate just enough convergence and
lingering moisture that isolated showers or maybe a thunderstorm
could develop for the next few hours, mainly in the upper parts
of Charleston County and far eastern Berkeley County. Therefore,
we maintained slight chance POPs in these locations. But the
mesoscale setup doesn`t favor anything strong and anything that
does manage to develop should dissipate around sunset. The
remaining locations across our area will be dry with just fair
weather cumulus.

Tonight: The mid-levels will consist of a longwave trough over
the eastern half of the U.S. At the surface, a stationary front
meandering along our coast in the early evening will transition
into a cold front by late evening, then move further offshore
and away from our area. Broad High pressure will be centered
over the northern MS Valley overnight, with its periphery
building into our region, especially after midnight. The
gradient should support very light surface winds, generally from
the NW. These winds will continue to usher lower dewpoints into
our area along with mostly clear skies. This should yield
decent radiational cooling for our area. Lows will range from
the lower 60s far inland to the lower 70s at the beaches.
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&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
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Zonal flow aloft prevails Wednesday into Thursday before an H5
shortwave dips toward the area from the north late Thursday into
Friday. At the surface, troughing persists offshore as high
pressure centered over the Great Lakes builds in from the west
Wednesday and Thursday. A very weak front will cross the area
Friday as the high shifts more over the Northeast and ridges
down the coast. Expect dry and warm conditions to prevail
Wednesday and Thursday under the strong subsidence aloft.
Thursday night and Friday are less certain as modest moisture
pooling ahead of the approaching front and modest lift ahead of
the approaching shortwave could coincide just enough to initiate
some showers and storms sometime Friday morning through
afternoon. Have expanded the slight chance POPs some Friday,
mainly near the coast, but overall expect moisture to be too
limited for much coverage, and mainly dry conditions still on
tap for Friday with temps trending closer to normal.
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&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
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Surface high builds in stronger Saturday and Sunday, then
pushes offshore early next week as a series of weak disturbances
possibly pass through. The weekend is trending drier with very
limited low level moisture available, then have trended toward a
more summerlike pattern for early next week, with storm chances
mainly along and inland of the sea breeze following a diurnal
pattern. Temperatures will be within a few degrees of climo
through the period.
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&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
18Z TAFs: VFR. Isolated convection could develop just north of
KCHS and KJZI for a few hours this afternoon near the
intersection of a weak sea breeze and a stationary front.
However, the probabilities of direct impacts to these sites is
very low, so we won`t include any mention in these TAFs.
Otherwise, winds will eventually turn to the NW by daybreak
Wednesday, as the front moves further offshore.

Extended Aviation Outlook: VFR.

&&

.MARINE...
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Tonight: A stationary front meandering along our coast in the
early evening will transition into a cold front by late evening,
then move further offshore and away from our area. The periphery
of broad High pressure will then build into our region,
especially after midnight. SW winds in the evening will shift to
the NW after midnight, generally remaining less than 15 kt. Seas
will be 2-3 ft.

Wednesday through Sunday: No marine concerns anticipated
midweek through the weekend with light to moderate winds
prevailing as high pressure builds in from the west through
Friday, shifting over the Southeast coast for the weekend.
Minimal income swell will keep seas around 2 ft or less through
Friday, with seas increasing to 2-4 ft over the weekend with the
introduction of medium period northeast swell.
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&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$

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