Area Forecast Discussion Issued by NWS Charleston, SC
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000
FXUS62 KCHS 280235
AFDCHS
Area Forecast Discussion
National Weather Service Charleston SC
1035 PM EDT Wed Mar 27 2024
.SYNOPSIS...
An area of low pressure and an associated cold front will
progress through the area tonight and then offshore Thursday
morning. High pressure will build in Friday and prevail through
early next week.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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Shower and thunderstorm coverage is beginning to increase from
the south and this trend should continue as we move through the
night with a front meandering over the area and deep moisture
in place (PWats of 1.4 off the 00z KCHS RAOB). Could see some
pockets of heavier rainfall with minor ponding on roadways and
in poor drainage areas, but widespread flooding issues are not
anticipated. Of late, there has also been a couple stronger
storms with one report of penny size hail. There is potential
for additional storms with stronger updrafts capable of
producing hail and stronger wind gusts, though this threat
should remain pretty isolated.
Highest rain chances should transition towards the coast late
tonight with decreasing coverage inland.
Breezy conditions will develop just before daybreak for areas
behind the front. Lows will range from the mid 50s well inland
to the upper 50s at the coast.-- End Changed Discussion --
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.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
Thursday and Thursday night: Aloft, a deep trough will swing
through the eastern portion of the CONUS during the day and
then shift offshore overnight. At the surface, the day will
begin with the cold front situated right along the coast with
the surface low just to the east. The front will shift offshore
in the morning and the post- frontal airmass will steadily
filter in through the rest of the day. The most active portion
of the entire period will be the morning when the front is still
lingering in the vicinity. The eastern half of the forecast
area will see scattered to numerous showers for a few hours
Thursday morning, and possibly an isolated thunderstorm. These
rain chances will quickly diminish from west to east and we
should be rain-free by around or just after noon. With the front
shifting offshore, winds will be gusty out of the north-
northwest with frequent gusts into the 20-25 mph range. Cloud
cover will decrease through the day and clear skies should
arrive by the evening and prevail through the overnight.
Thursday highs are forecast to peak in the mid to upper 60s with
overnight lows in the low to mid 40s.
Lake Winds: Strong north-northwesterly winds are expected across
Lake Moultrie on Thursday as a cold front moves offshore. Gusts
could be near 25 knots and a Lake Wind Advisory could be needed.
Friday through Saturday: Dry high pressure will build in Friday
and prevail into the first half of the weekend. Friday highs
are forecast to top out right around 70 with overnight lows
mostly in the mid to upper 40s. Saturday will bring a notable
warm up with above normal temperatures. Highs are forecast to
reach the upper 70s in most areas away from the immediate
coastline.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Broad ridging will gradually build across the eastern CONUS
late this weekend and through early next week, with the
possibility of the next trough approaching the area by the
middle of next week. Dry conditions and warm temperatures are
expected through most of the period. Highs are expected to reach
the low to mid 80s Sunday through at least Tuesday, with a
return to the 70s for Wednesday as a front moves in for
Wednesday and also brings our next chance of rain.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
Conditions are expected to deteriorate to MVFR and eventually
IFR levels later this evening and overnight as rain and low
clouds spread into the terminals. Maintained tempo group for
best timing of thunder and lower visibilities. Rain should exit
Thursday morning shortly after daybreak, but low clouds will
linger through much of the day. VFR should return late in the
day. In addition, gusty north winds in the 20-25 kt range will
develop as a cold front moves offshore in the morning.
Extended Aviation Outlook: VFR conditions will prevail.
&&
.MARINE...
Tonight: Showers/tstms will impact the coastal waters overnight
as low pressure moves through the area along a quasi-stationary
front. Southerly winds will become more southwest overnight.
Sustained winds will largely remain below 15 kt outside of
tstms. Wind gusts to 35kt could occur with any of the stronger
tstms, so Special Marine Warnings may be needed at various
times through the night. The cold front is expected to clear the
coast just before daybreak Thursday. Winds will pick up quickly
after FROPA with gusts near 25 kt. The bulk of these will hold
off until after sunrise. Seas will hold 2-4 ft nearshore waters
within 20 NM and 4-6 ft over the Georgia offshore waters from
20-60 NM offshore. A Small Craft Advisory continues for the
Georgia offshore waters tonight.
Thursday through Monday: The cold front will be positioned along
or just off the coast Thursday morning. The front and an area of
low pressure will move away from the coast through the rest of
the day and a period of strong north-northwesterly flow is
expected into at least early Friday morning. A period of solid
Small Craft Advisory conditions is expected for all waters. The
outer Georgia waters advisory is already in effect and runs
through Friday morning. We have issued advisories for all
nearshore waters, going into effect Thursday morning and then
ending at various times Thursday afternoon through late Thursday
evening. Frequent gusts into the 25-30 knot range are expected,
strongest in the Charleston County waters and the outer Georgia
waters. An advisory might also be needed for Charleston Harbor
for the daytime hours on Thursday, with gusts near 25 knots.
Conditions will improve significantly late Thursday night
through Friday morning as the gradient relaxes. Then this
weekend into early next week, southwest flow will settle in and
prevail with periods of time where wind speeds will surge into
the 15-20 knot range at times.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory from 8 AM to 10 PM EDT Thursday for
AMZ350.
Small Craft Advisory from 8 AM to 6 PM EDT Thursday for AMZ352.
Small Craft Advisory from 8 AM to 4 PM EDT Thursday for AMZ354.
Small Craft Advisory until 8 AM EDT Friday for AMZ374.
&&
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AVIATION...
MARINE...