St. Andrews, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

940
FXUS62 KCAE 211106
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
606 AM EST Thu Nov 21 2024

.SYNOPSIS...
A drier and colder airmass will settle across the region into
the weekend. Gusty winds are expected once again this morning
and into the afternoon hours, with gusts of 30-40 mph possible.
Dry weather continues this weekend, with slowly rebounding
temperatures across the area.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Message(s):

- Colder and drier air continues to settle into the region.
- Strong and gusty winds will remain today into this evening.
- Frost possible tonight everywhere, along with freezing
  temperatures over the northern Midlands.

Cold front has exited off the east coast. Behind it, much drier
and colder air has moved into the region. Strong pressure
gradient will create a breezy conditions through the day, with
wind gusts over 30 mph possible in places. Lake wind advisory
remains in effect into this evening. With good cold advection,
even under sunny skies, afternoon temperatures will remain in
the 50s for highs. Tonight will see a drop off in winds,
although sustained winds up to 10 mph will remain possible.
This will bring a good amount of cold advection and continued
drier air in from the north overnight.

As for temperatures tonight, guidance indicating portions of
the northern Midlands will have the potential to drop down to
around freezing late tonight. Many of the ensemble members
indicate a range of temperatures slightly above freezing, with a
number also at or below freezing across the north. Due to this,
have issued a Freeze Watch for the Northern Midlands late
tonight. Remaining forecast area should drop into the middle
30s, which would bring potential for frost in sheltered areas.
Frost may be limited due to dry air and winds through the night
however. Have held off on any advisory for now, and will let
later shifts evaluate the potential for frost/freeze product
upgrades for tonight.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
Key Message(s):

- Cooler Friday with breezy conditions possible Friday night.

Strong low pressure to the north of the area Friday with NAEFS mean
indicating the MSLP over the Mid Atlantic is near the climatological
minimum for this time of year. The low will be further away from the
area, however, with 850mb winds around 25 knots and decreasing
through the day. While winds may be breezy Friday, they are not
expected to be nearly as strong as Thursday. Northwest winds aloft
will once again promote downslope flow, reinforcing the already dry
airmass. Temperatures a bit cooler Friday, mostly in the mid-50s.
Upper level low over the Mid Atlantic will steer the surface low
farther south with increasing winds aloft tonight, although the
highest 850mb jet will likely be just to the north of the area. By
the time of this low level jet development, it is likely that a
surface inversion will develop, preventing much of it from mixing
down, but a Lake Wind Advisory may be needed Friday night due to
more favorable mixing over the lakes, especially in the northern
portion of the forecast area. Cold advection will once again support
lows in the mid-30s to near freezing.

As the upper low shifts to the east Saturday, rising heights will
lead to temperatures recovering, although still a few degrees below
seasonal average, in the low 60s. Dry weather persists with
ensembles indicating a high probability of PWATs remaining at or
below a half inch. Lows once again generally in the mid-30s as
high pressure moves over the southeastern US, promoting strong
radiational cooling, although stayed near blended guidance as
forecast soundings indicate a weak low level jet could prevent
ideal radiational cooling.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Key Message(s):

- Gradually warming but dry pattern into early next week.
- A bit more unsettled weather possible by midweek.

High confidence among ensemble members in dry weather continuing
through Monday with majority of members indicating PWATs remaining
at or below a half inch. By early next week, ridging begins building
over the area with GEFS and EPS means favoring above average 500mb
heights leading to highs several degrees above average, in the upper
60s and low 70s. Moisture will increase ahead of another cold front
late Monday into midweek. Uncertainty as to the timing of this
frontal passage and whether or not it pushes south of the area or
stalls so hard to pin down exactly when rain will be most likely
at this point. As a result, a bit more unsettled towards the
end of the period, although total blended rainfall through
Wednesday remains only around a tenth or two.

&&

.AVIATION /11Z THURSDAY THROUGH MONDAY/...
VFR is forecast for the entire period.

Cold front is east of the area. Drier airmass will continue to
move into the region the next 24 hours, keeping mostly clear
skies at all taf locations. Biggest issue through the period
will be the winds and associated gusts. Winds through sunrise
around 5 knots out of the west, then winds are expected to
become gusty again through the daytime hours, especially after
15z with frequent gusts of 25-30 knots forecast through the day.
Wind direction is expected to be westerly to northwesterly
through the period.


EXTENDED AVIATION OUTLOOK...Strong and gusty winds expected
again on Friday with gusts in excess of 25 knots possible.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...Lake Wind Advisory until 7 PM EST this evening for SCZ016-018-
     020>022-025>031-035-037-038-041-115-116-135>137.
     Freeze Watch from late tonight through Friday morning for
     SCZ016-020>022-029-115-116.
GA...Lake Wind Advisory until 7 PM EST this evening for GAZ040-
     063>065-077.

&&

$$