101
FXUS62 KGSP 100627
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
127 AM EST Wed Dec 10 2025

.SYNOPSIS...
High pressure will move off to the east today as a cold front
approaches from the northwest. The front should move through
tonight, with precipitation chances limited to the Tennessee border
areas. High pressure returns Thursday and into the weekend ahead
of an arctic cold front which arrives early Sunday.  Dry and cold
high pressure will move in briefly for the start of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1:20 AM EST Wednesday:

Key message 1: Gusty winds developing this morning and persisting
thru this evening.

850mb winds will ramp up overnight with a LLJ advancing across KY/
TN thru daybreak preceding the axis of the main upper shortwave.
Higher elevations should see 15 to 25 mph winds develop by sunrise.
Cloud cover will be tricky to fcst through the morning, but still
expecting clouds to remain sct enough to allow more rapid warming
than we saw Tuesday morning, which should allow for mixing of the
gusty winds to begin early in the day. Most of our lower elevations
are expected to see gusts approaching 30 mph by late morning, with
higher elevations seeing 30 to 40 mph gusts by that time as the core
of the LLJ passes over the mtns/foothills. Compressional warming and
some amount of sunshine should warm temps back into the 50s for most
locations below 3500 ft this afternoon; The strongest 850mb winds are
expected over the Piedmont during peak heating, suggesting frequent
30 to 35 mph gusts and peak gusts likely near 40 mph.

Key message 2: Northwest flow snowfall developing this afternoon/
evening near the Tennessee border.

Significant cold-air advection will commence in the wake of the LLJ
passage, with the base of the upper shortwave progged to pass over
the Appalachians around 00z Thursday. Winds turn WLY this afternoon
along the TN border and to the NW near the base of the trof, with
accompanying upslope moisture. Sfc temps should fall rapidly over
the mtns by sunset and the top of the moist layer will approach
favorable temps for ice nucleation, with cooling overcoming the
increasingly shallow moisture. The most favored NW flow locations
along the NC/TN border are expected to see roughly 2 to 5 inches
of snow by 12z Thursday. This also includes a good portion of Avery
County. However, further from the border, zone averages across our
TN border counties are not high enough to warrant a Winter Weather
Advisory at this time.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 1225 AM EST Wednesday...No messages are particularly `key`
for the late part of the week. A NW flow snow event should wind
down early in the morning on Thursday with maybe some lingering
flurries over the northern mountains. After that, the rest of the
late week part of the forecast looks like middle of winter kind of
stuff as we remain under a deep WNW flow aloft. High temps Thursday
will be 5-10 degrees below normal. Guidance continues to show the
next short wave missing us to the north Thursday night and Friday,
so some light rain/snow might nip the nrn part of Avery County,
but otherwise it should be dry. Otherwise, sfc high pressure will
build in from the west and the air mass should modify for Friday,
with the srn half of the fcst area returning close to normal. The
prolonged WNW flow will keep a S-to-N temperature gradient across
the region, so places to the north of I-40 might remain a few
degrees on the cooler side of normal.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 1253 AM EST Wednesday...

Key Message #1: Above normal temps Saturday.

The forecast for the weekend continues to drift and trend as
run-to-run consistency has been mediocre. The latest guidance
shows the upper pattern flattening even more across the region on
Saturday, with fairly deep warm advection spreading overhead by the
afternoon. That combined with strong and more westerly downslope
flow, and nearly full sun, will contribute to temperatures likely
climbing above normal for the first time since Thanksgiving
on Saturday afternoon. Should be an enjoyable day if this
works out, although confidence is average because of the model
drift. Fortunately, the trend continues to be toward the warmer
and drier.

Key Message #2: Model guidance trending back toward a dry frontal
passage Saturday night into Sunday.

That moving target aspect of the forecast is most apparent on
Saturday night into Sunday with the next clipper system rotating
through the eastern upper trof. The new guidance still has a strong
short wave which brings the trof axis across the area Saturday
night, but the model consensus is to move the vort center past us
well to the north. As a result, the previous injection of western
Gulf moisture looks like it won`t amount to much, and the better
forcing and low level moisture associated with the wave will for
the most part miss us to the north. The model blend still retains
some small precip chances over the mtns for Saturday night, but
this is starting to look more like a hold-over from the previous
runs as the newer guidance trends drier.

Key Message #3: Breezy behind the cold front Sunday, with a much
colder air mass for the start of next week.

The arctic front looks like it will cross the region early in the
day on Sunday, but downslope flow east of the mtns will help to
keep temps still somewhere between normal and five under through
the afternoon. Expect it to be a breezy day, at least across
the mtns, assuming the pressure gradient across the barrier is
as strong as depicted by the GFS. The strong cold air advection
should take over through the late afternoon and temps will plummet
after dark. Monday still looks like the chilly day as the heart of
the cold air mass moves through. Temps still look like something
on the order of 15 degrees below normal. Alas, modification will
be quick as the pattern finally becomes progressive, and quickly
at that. By Tuesday, the trof axis already swings offshore and the
sfc high moves off to the east, allowing for a quick rebound toward
normal on the temperatures. An upper ridge moves in by Wednesday
and we may feel some effects from a southern stream wave by then,
but confidence on the timing is low. Either way, the pattern looks
like it would favor just rain.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: A broad area of high clouds has been moving
eastward over the fcst area for the past few hrs. Guidance still
shows drying likely to continue above the PBL overnight, with an
inversion being reinforced nocturnally. There is some potential for
a shallow moist layer to produce some lower cloud decks overnight
and into the morning, however strengthening winds still appear to
be the main limiting factor in that scenario. For this taf issuance,
I don`t have any restrictions. The LLWS threat increases toward day-
break and is mentioned at all taf sites at some point between 10z and
18z. Otherwise, winds pick up from the S to SW by sunrise across the
area with gusts commencing. All sites are expected to see 25 to 30 kt
gusts this afternoon, with a few peak gusts of 35 to 40 kt possible.
Winds will veer around to more WLY/NWLY this evening with lower-end
gusts lingering across the area thru light tonight.

Outlook: NW flow snow showers expected along the NC/TN border Thurs
night into Fri with MVFR restrictions possible at KAVL during that
period. Otherwise, expect mostly dry/VFR conditions elsewhere thru
the weekend.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$

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