Area Forecast Discussion Issued by NWS Charleston, SC
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCHS 050256
AFDCHS
Area Forecast Discussion
National Weather Service Charleston SC
956 PM EST Thu Mar 4 2021
.SYNOPSIS...
High pressure will prevail into next week, aside from a low
pressure system to the south brushing the area late this week
into the weekend.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Clear skies and light winds will persist through early Fri
morning. A weak backdoor cold front will drop through later
tonight, bringing a slight increase in surface winds. Overnight
lows will likely range in the low/mid 40s for much of the area,
but should stay in the upper 40s to around 50 degrees along the
immediate coast.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
High pressure will approach the region as a cold front shifts
further south on Friday. All the while, a deep mid to upper level
trough centered across eastern Canada will dig into the region and
shortwave energy associated with the trough will help advect
moisture into the area. Cloud cover is expected to increase late
Friday night before clearing out on Sunday. There are some 12Z model
discrepancies so still unsure of how much precip coverage the area
will receive. Though, did limit POPs over land to slight chance and
over the waters to chance. Any showers that do form should be light
and no accumulation is expected. Winds could become gusty at times,
mainly along the coast.
High temperatures will be in the 60s on Friday, then mid 50s to low
60s on Saturday and Sunday. Friday night low temps will be in the
upper 30s to mid 40s. On Saturday, lows will be in the mid to upper
30s. While temps will be conducive for frost formation, Saturday
night will not be a great night for radiational cooling and
conditions seem too dry for widespread frost.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
High confidence this period as models are in decent agreement
keeping high pressure in control with mainly dry weather, although
there is a small chance for a few showers mid week as a coastal
trough develops. The main forecast challenge will revolve around
temperatures, which should stay below normal until possibly getting
back near normal Tuesday. Still possible to see some frost and/or
freezing temperatures inland each morning through Tuesday, with the
best chance of a freeze Sunday night. Note that now that we`re back
into the growing season we will be issuing Frost Advisories and
Freeze Watches/Warnings as needed.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR.
Extended Aviation Outlook: While lower ceilings might develop
late Friday into Sunday, prolonged flight restrictions are not
expected.
&&
.MARINE...
-- Changed Discussion --
Fairly weak SW flow through early Fri morning will turn N and
strengthen later tonight behind a backdoor cold front. Cold air
advection behind the front and a tightening of the pressure
gradient will support a northerly wind up to 15-20 kt at times
and seas up to 2-4 ft. Wind gusts could briefly touch 25 kt
across some waters approaching daybreak, but the event will be
quite limited in duration. Thus, a Small Craft Advisory is not
needed at this time.
Friday through Tuesday: NNE winds will prevail through Tuesday. As
shortwave energy associated with an mid to upper level trough passes
across the waters, the pressure gradient will become pinched. Winds
will be 15-20 knots with occasional gusts to 25 knots and seas could
approach 6 feet. Small Craft Advisories could be needed starting
Friday, then again on Saturday though conditions seem marginal at
this time. By late Sunday, winds and seas will subside as high
pressure prevails.-- End Changed Discussion --
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...JRL
SHORT TERM...RAD
LONG TERM...RJB
AVIATION...JRL
MARINE...JRL/RAD