268
FXUS62 KGSP 011817
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
117 PM EST Mon Dec 1 2025

.SYNOPSIS...
Low pressure moves northeast from the Gulf tonight and Tuesday with
widespread precipitation. Behind the system, high pressure will
result in chilly and dry conditions Wednesday and Thursday.
Unseasonably cold and unsettled weather is expected Friday as
another system brings more precipitation to the area.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 1258 PM EST Monday...

Key Messages:

1) Fair and cool today as high pressure passes by.

2) Precip develops from the southwest this evening, mostly rain,
but with pockets of freezing rain over the northern mountains and
along/near the Blue Ridge Escarpment in North Carolina.

3) A Winter Weather Advisory has been expanded to include parts
of Buncombe/Henderson/Polk/Rutherford counties, from 7 PM Monday
through 10 AM Tuesday.

Fair weather prevails this afternoon and into the early evening
as sfc high pressure migrates from the Great Lakes to New
England. Meanwhile, the short wave seen in the water vapor imagery
coming out across the srn Plains will help increase moisture return
from the southwest. Precip probs have been pushed back further
based on the 12Z HREF and the expectation that developing precip
will have a difficult time working northeastward into the dry air
across our region.

But, develop it will, as the 850mb flow improves quickly this
evening, increasing the moisture flux and contributing strong
isentropic lift that spreads northeast between 00Z and 06Z to
engulf the entire fcst area. Thus, precip probs will be ramped
up all the way to categorical SW to NE in that time frame. The
slightly later start might allow for a bit more cooling down
farther to the S/SW along the Escarpment, such that when the precip
arrives the temps will have an easier time wet-bulbing down to
around freezing. Meanwhile, strong warm advection will develop a
formidable warm nose overhead. The upshot is that after some mixed
precip potential at onset mainly over the mtns, we end up with an
R/ZR situation. The majority of the region will have nothing but a
cold rain, but the usual areas over the nrn mountains and near the
Blue Ridge Escarpment from Blowing Rock down to Saluda, including
the eastern-most parts of Buncombe and Henderson counties should
see a period of freezing rain starting late this evening. The warm
nose makes the situation elevation-dependent, so places that are
above about 4000 feet or so should be mostly rain after some mix
at onset. There is enough icing potential to expand the Advisory
down south to include the mountain parts of Polk and Rutherford
and also Henderson and Buncombe. NOTE that the ice potential
will be east of a line from roughly Swannanoa to Fairview and
Edneyville, with little to no accumulation expected in Asheville
and Hendersonville and west of the I-26 corridor. Of course,
things could go wrong. The most likely failure mode would be that
colder air is more extensive which could require expansion across
the NC Foothill zones, or that the cold air holds on longer and
allows for some icing to approach or exceed Warning criteria. The
warm advection should be strong, so precip should be all rain by
around daybreak. Temps will naturally be at or below normal.

The precip will move off to the east steadily and should be over
by early afternoon. Assuming we get some partial clearing and
dry air in the afternoon once the sfc wave moves to the east,
temps could rebound to around normal.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 1237 PM EST Monday:

Key Message 1: Northwest flow in the midst of ending Tuesday evening
following the departing system from the Near-Term period. Most
locations across the area below freezing for overnight lows Tuesday.

Ongoing northwest flow precip should fully diminish by Tuesday
evening along the immediate Tennessee border as drier air disrupts
the shallow layer of moisture along the favorable upslope zones.
Weak surface high will move in from the northwest as CAA works into
the CWFA. Gusty winds gradually subside across the mountains
overnight Tuesday as the center of the surface high shifts into the
OH/TN Valleys. Temperatures will be in the upper teens and 20s
across the mountains with mid to upper 30s elsewhere for overnight
lows with decent radiational cooling conditions outside of boundary
layers struggling to fully decouple.

Key Message 2: Dry weather Wednesday and Thursday with temperatures
rebounding from Wednesday to Thursday.

Weak surface high moves across the southeastern CONUS on Wednesday
as low-amplitude ridging settles over the region in response to a
digging upper trough over the western CONUS. A cold front is shown
encroaching the CWFA from the northwest on Thursday as the front
sags through the area without much fanfare as better forcing for
ascent remains north and available moisture stays south over a
developing baroclinic zone over the Gulf Coast region. In this case,
not much change to the overall airmass. Temperatures will be cool
Wednesday with afternoon highs in the 40s in the mountains and upper
40s to lowers 50s across the Piedmont. Overnight lows should run
below freezing with 20s and lower 30s expected with good radiational
cooling conditions in place. Weak downslope component should help
bump temperatures a few degrees higher compared to Wednesday for
afternoon highs on Thursday.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 115 PM EST Monday:

Key message 1: Next system moves into the western Carolinas
and northeast Georgia late Thursday into Friday, with wintry
precipitation possible, mainly across the mountains as a result
of another cold-air damming event. Confidence remains low overall
for occurrence of precipitation and winter weather.

Stronger surface high (~1030mb) moves in behind the short-term
cold front as it shifts from the Midwest through the OH Valley
and offshore the Mid-Atlantic Thursday night through Friday. The
aforementioned cold front will stall south of the CWFA, in the
vicinity of the I-20 corridor. Activated baroclinic zone over the
southeastern CONUS will induce Miller-A surface cyclogenesis along
the boundary as it becomes reactivated and develop a low pressure
system as the next storm system moves across the eastern Gulf
Coast Friday and over the Carolina Coast Friday night. Latest
model guidance have trended drier with a shorter period of good
QPF response. The complicating factor will be the strength of the
in-situ CAD as it develops Friday as the onset of precipitation
Friday morning could start out with a mix bag of wintry precip
in the North Carolina mountains/foothills, as well as the I-40
corridor before transitioning to all liquid for most locations. The
probability of any accumulating snow or ice remains confined to
the northern Blue Ridge mountains at this time, especially now
with the latest trends keeping the system slightly further south,
which in turn, limits the overall available moisture. However,
this would limit the presence of a strong warm nose, which could
lead to more of snow/sleet across the high elevations instead
of a predominately freezing rain event. Still a lot of factors
to consider, but the potential for another nuisance winter system
across the mountains is definitely in the playing cards. Elsewhere,
outside of the mountains, model solutions, including ensembles
indicate mostly a cold rain. Either way, temperatures will be cold
on Friday with most locations in the 30s and 40s across the CWFA,
with near freezing temperatures in the mountains/foothills, where
the chance for wintry precip is best.

Key message 2: Calmer weather in store for the latter half of the
weekend into early next week. Slight rebound in temperatures with
trends keeping values near normal.

One consensus that model guidance are picking up on is the overall
end time of the weekend system as precip could linger into Saturday
before shifting east of the CWFA by Saturday night as a southern
stream shortwave aids in a faster storm departure. Precip chances
have reflected this in the latest forecast update as trends have
lowered to slight chance (15-24%) and chance (25-54%) PoPs across
the area and fully drying out by early Sunday. If the latest
model guidance continue with a drier trend, then the main precip
timing will be Friday and Friday night with less coverage for
Saturday. Weak cyclonic flow aloft remains in place through the
weekend as another shortwave is shown swinging within the mean flow
and approaching the area by the end of the weekend. Guidance differ
on the overall QPF response, but looks light overall, even with the
more aggressive solutions. Slight chance PoPs are introduced across
the mountains Sunday night, but remains dry elsewhere. Temperatures
continue to run within a few degrees of normal over the weekend
into the early next week, but is subject to change depending on
how long CAD lingers, especially for Saturday.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
At KCLT and elsewhere: VFR conditions will persist past sunset
and probably thru the late evening, but clouds will thicken after
sunset and ceilings will start to drop as moisture spreads quickly
northeastward. Wind should be NE. The development of light precip
after about 02Z from SW to NE will bring the ceiling steadily
down thru MVFR and into the IFR to LIFR range at all terminals
in the late night/early morning hours. By the start of operations
in the morning, it should be raining at all terminals with an IFR
restriction most likely. Due to the strong SW flow, there could be
some LLWS across KAVL at that time. Variability between LIFR and
MVFR can be expected. Precip type looks to be just a cold rain at
all terminals, but will have to monitor KAVL and KHKY for possible
freezing rain before daybreak. Temps warm by 13Z and that should
end that threat. The system moves thru fairly quickly. Ceilings
may crash to LIFR around daybreak as the precip starts to taper
off. Quick improvement is expected right around the end of the
period, with wind coming around to SW to W.

Outlook: VFR conditions return Tuesday night into Wednesday. Another
system may bring rain and associated flight restrictions to the
region on Friday and into the weekend.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Winter Weather Advisory from 7 PM this evening to 10 AM EST
     Tuesday for NCZ033-049-050-053-065-501-503-505-507-509.
SC...None.

&&

$$

SYNOPSIS...DEO
NEAR TERM...PM
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...PM