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Area Forecast Discussion (AFD)

Issued by Charleston, SC (CHS)

FXUS62 KCHS 211524

Area Forecast Discussion
National Weather Service Charleston SC
1124 AM EDT Thu Mar 21 2019

A cold front will move into the region from the west late today
and then offshore tonight. High pressure will then build into
the region and persist through the weekend. Low pressure may
move through the Southeast on Tuesday. 


Today: Low pressure centered along the Mid-Atlantic states will exit 
to the north/northeast and away from the area late this morning, 
setting up a westerly flow along the base of a mid/upper lvl trough 
of low pressure shifting across the area this afternoon. The pattern 
will generally result in warmer conditions today as west-southwest 
sfc winds occur ahead of a dry cold front that eventually passes 
through the area late this afternoon. In general, high temps should 
approach the upper 60 to lower 70s under a full sun. These temps 
suggest mixing profiles supportive of wind gusts as high as
15-25 mph during peak heating, highest across Southeast Georgia
and coastal South Carolina where sfc temps are warmest this 

Tonight: The cold front is expected to move offshore by early 
evening with the atmosphere too dry to expect any brief showers 
across northern SC zones. There should be a brief period of mid 
clouds then skies will become mostly clear. Low will be in the 40-45 
degree range and most all areas are expected to maintain a light WNW 
breeze overnight.


Strong continental high pressure centered over the Plains states 
Friday will move just north of the Southeast region Saturday, then 
offshore by late Sunday. It will bring our area dry conditions with 
mostly clear skies. Temperatures will be within a few degrees of 


High pressure will move offshore Sunday night. A coastal trough is 
expected to form Monday while a storm system approaches from the 
west. Models show the system moving through Monday night, then 
perhaps stalling along or just off our coast through Wednesday while 
high pressure prevails inland and to our north. Though, there 
remains uncertainty over the timing, strength, and the track of this 


VFR conditions will prevail at both CHS and SAV terminals through 
12Z Friday. West-southwest winds could up to around 20 kt at times 
this afternoon, especially at the SAV terminal. 

Extended Aviation: VFR through Sunday. There are low probabilities 
of flight restrictions due to an approaching storm system on Monday.


Today and Tonight: West winds late this morning will gradually back 
to southwest and peak near 15-20 kt at times ahead of a cold front 
approaching late this afternoon/evening. Winds should be highest in 
offshore Georgia waters and northern South Carolina waters. Seas 
will generally peak near 4-5 ft beyond 10 nm in nearshore waters and 
4-6 ft in offshore Georgia waters. A Small Craft Advisory will 
therefore remain in effect across offshore Georgia waters today.
Overnight, jetting and surging offshore flow in the wake of the cold 
front will likely support the continuation of a Small Craft Advisory 
across offshore Georgia waters and potentially across all nearshore 
waters. In general, west-northwest winds could gust as high as 20-25 
kt while seas build up to 5-7 ft, highest across offshore Georgia 

Extended Marine: High pressure will prevail across the region 
through the weekend. Low pressure may move through the Southeast on 

Rip Currents: A moderate risk for rip currents continues today as 
lingering 2-3 ft swell energy occurs and southwest winds gust up to 
15-20 mph at times along the beaches, but conditions should begin
to improve by late afternoon. 


A dry cold front will move into Southeast Georgia this afternoon.
Winds are expected to become gusty with 20-23 kt gusts forecast
for at least 2-3 hours. In addition, RH values will fall to 
near critical values. Fuels in this region are the lowest in our
forecast area, but values appear marginal. Per collaboration 
with SPC Fire Weather, all of Southeast Georgia is in an elevated
potential for fire danger this afternoon. A Fire Danger Statement
is in place for this region for anticipated afternoon conditions.

Friday: RH values as low as 25-30 percent and elevated offshore
winds could also cause fire concerns, especially if partners 
report low fuel moisture.


MARINE...Small Craft Advisory until noon EDT Friday for AMZ374.