079
FXUS62 KGSP 220850
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
350 AM EST Wed Jan 22 2025

.SYNOPSIS...
Arctic high pressure slowly weakens through the end of the work
week. The air mass will gradually modify by this weekend with
temperatures returning to around normal along with a return of
precipitation chances Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages:

1) Snow has ended across our forecast area, however the current
Winter Weather Advisory will remain in effect until 9 AM this
morning due to lingering hazardous road conditions.

2) A Cold Weather Advisory is in effect until noon today for all
counties except Avery, where an Extreme Cold Warning is in effect.

3) Dry conditions will prevail today with cold air still in place
across the region.

As of 3:15 AM EST Wednesday: Satellite imagery is still showing the
broad high cloud shield covering the eastern half of our CWA. It has
been gradually retreating eastward over the past several hours, but
doing so a bit slower than anticipated. As such, temperatures may not
be able to cool quite as much as expected this morning, especially
over our eastern zones. Regardless, wind chills will still likely
reach Cold Wx Advisory criteria (or get close) before the morning
is over. The other main concern this morning will be the road con-
ditions. Conditions have likely deteriorated since last night on
some roads as any moisture refroze. Thus, the Winter Wx Advisory
will remain in effect until 9 AM this morning to highlight these
hazards. For areas to the north, a Special Weather Statement remains
in effect until 9 AM to reflect the potential for slick roads this
morning.

Otherwise, an elongated upper shortwave will move overhead and then
lift off the Atlantic Coast this afternoon. In its wake, upper-level
flow becomes more zonal to end the period. At the same time, the back-
side of the broader upper trof will amplify again over the central
CONUS. At the sfc, another robust, reinforcing high will spread over
our region from the NW today and linger into the next period. Thus,
today/tonight will be dry, cold, and mostly sunny. The main concern
continues to be the Arctic air that will persist thru the period.
High temps today will struggle to climb much above freezing for most
of our fcst area, although highs will be about a category warmer than
Tuesday across most of our mtns zones and 1 to 2 categories warmer
above roughly 3500 ft. Lows early Thursday are still on track to be
in the teens outside the mtns and teens to single digits over the mtns,
but with weaker winds expected tonight and early Thursday, it doesn`t
look like we will reach Cold Wx Advisory criteria for any of our zones.
Avery County is expected to come close, but not quite.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 150 AM Wednesday: An upper trough will persist across the
eastern and central CONUS Thursday into Friday, as a series of
shortwaves dive into the trough axis. The trough will finally
eject east Friday night, pushing a weak, dry cold front thru
the forecast area. Periods of stratocu may bank up along the
slopes near the TN border Thursday night thru Friday with temps
supporting a few flurries or isolated snow showers. Overall,
guidance continues to show basically no QPF response as moisture
depth is just too shallow. The rest of the area may see some
thick mid and high clouds as shortwave energy passes by, mainly
Thursday. Otherwise, dry conditions expected with temps remaining
well below normal, but with a gradual warming trend, as the arctic
air mass moderates. Highs 10 to 15 degrees below normal Thursday
and around 10 degrees below normal Friday. Wind chill values will
drop into the single digits across the higher elevations Thursday
night, with upper teens to lower 20s elsewhere.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 230 AM Wednesday: The upper flow becomes zonal to start the
medium range, but split flow will develop once again across the
West. The 00z guidance still is not in great agreement on a closed
low forming over California, while a northern stream trough digs
into the Upper Midwest. The low looks to become cutoff, but some
energy may eject from it out into the Plains Sunday, inducing a
weak sfc wave over Texas. That low may spread some moisture east
across our region Sunday night thru Monday, but the 00z guidance has
trended drier, shunting the moisture south. Meanwhile, temps will
continue to moderate toward normal. By the time moisture arrives,
temps will support mainly just rain, except perhaps in the higher
elevations which may see a wintry mix. The National Blend of Models
has chc PoPs Monday, which may be overdone if the model`s continue
to trend weaker/shunted with the low. Temps are also tricky Sunday
night, as guidance has lows near to slightly below freezing across
most of the forecast area. Given the uncertainty in the forecast,
stuck with just RA/SN, but some sleet and/or FZRA may be possible,
if a warm nose sets up. Dry weather returns with mild high pressure
building in Tuesday and Wednesday. Temps may actually warm a few
degrees above normal.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: With the snow showers having moved east of
our area over the past few hrs, we can expect dry, VFR conditions
to prevail thru the 06z taf period at all terminals. BKN/OVC high
clouds remain over most of our area, but they should clear from west
to east over the next 6 hrs or so, with mostly clear skies expected
by roughly 12z and for the rest of the taf period. Outside the mtns,
winds will remain N to NE thru the morning and then gradually veer
to more ELY and then SELY as the day wears on. They are expected
to go light and VRB to calm later tonight. At KAVL, winds will
remain N to NW thru the overnight/morning with gusts tapering
off by roughly 12z this morning. They will toggle around to SE
this afternoon, and then go light and VRB later this evening.

Outlook: Broad high pressure builds back over the region on Wed-
nesday and will persist thru the weekend, with VFR conditions
prevailing.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Cold Weather Advisory until noon EST today for GAZ010-017-018-
     026-028-029.
     Winter Weather Advisory until 9 AM EST this morning for GAZ017-
     018-026-028-029.
NC...Cold Weather Advisory until noon EST today for NCZ035>037-
     048>053-056>059-062>065-068>072-082-501>510.
     Winter Weather Advisory until 9 AM EST this morning for
     NCZ070>072-082.
     Extreme Cold Warning until noon EST today for NCZ033.
SC...Cold Weather Advisory until noon EST today for SCZ008>014-019-
     101>109.
     Winter Weather Advisory until 9 AM EST this morning for
     SCZ009>014-019-104-107-109.

&&

$$

SYNOPSIS...ARK
NEAR TERM...JPT
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...JPT