639
FXUS62 KGSP 071823
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
123 PM EST Fri Nov 7 2025

.SYNOPSIS...
Rain chances return tonight and continue off and on through Sunday.
A strong cold front makes a full passage Sunday and will filter in
an arctic airmass Sunday night through Tuesday. Mountain snow along
the NC/TN border is expected Sunday night through Monday.
Temperatures gradually rebound after Tuesday, with dry conditions
expected.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 1057 AM Friday: A broad mean trough remains draped across the
country with several embedded shortwave troughs. The first in the
series of troughs is currently dropping across the middle
Mississippi Valley and into the Ohio Valley. This feature will slide
across the Appalachians tonight with an associated surface cold
front encroaching on the mountains. Moisture pooling ahead of the
boundary across the Tennessee Valley will foster a reservoir of 500-
750 J/kg of mixed-layer CAPE over east Tennessee within a moderately
sheared environment. The 12z suite of CAMs is in good agreement that
a band of deep convection will blossom ahead of the frontal boundary
across Middle Tennessee late this afternoon and move east towards
the area this evening. Convection is expected to move into the
mountains late evening into the early overnight hours with at least
scattered showers surviving east of the mountains into the foothills
and Piedmont. Any lingering showers should push east of the area by
or just after sunrise tomorrow morning. The main focus will be the
potential for a few strong to isolated severe storms over the
mountains late this evening. 200-400 J/kg of mixed-layer CAPE is
being progged by guidance with 40-50 kts of deep-layer vertical wind
shear. This should be sufficient to maintain at least some degree of
linear structure into the first tier of counties along the Tennessee
border. Any bowing segments and/or surges in the line will be prime
candidates for locally gusty winds with an isolated severe storm not
out of the question. Any isolated severe threat will quickly
diminish as the remnant line pushes east as instability further
wanes.

Heading into tomorrow, the lead shortwave trough will be quickly
pulling away from the area with a second trough diving out of the
central Rockies and into the central Plains. This will leave the
Southern Appalachians within a broad area of nebulous forcing and
quasi-zonal flow in the base of the trough. The trailing surface
cold front will become increasingly oriented parallel to the upper
flow and will likely stall in the vicinity or over portions of the
area. This will support a rather warm day with afternoon highs
climbing into the low to mid 70s outside of the higher elevations.
Modest instability will likely reside along and south of I-85 within
a well sheared environment, but a dearth of forcing and rather muted
QPF response will preclude any severe threat due to a lack of
convection to begin with.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 104 PM EDT Friday: A digging trough will be in the midst
of sinking southward across the central CONUS at the start of the
forecast period. A weak stationary boundary should help to activate
some showers and a couple of thunderstorms Saturday night before
the attendant, reinforcing cold front encroaches the area by the
daytime period Sunday. Strong height falls will accompany the front
as it makes a full fropa by the Sunday evening. Ahead of the front,
guidance is depicting some convection developing with an environment
consisting of a couple hundred J/kg of instability and strong deep
layer shear (50-60+ kts of 0-6km bulk shear). This may lead to a few
strong to possibly s severe storm, but this threat seems to become
more realized just east of the I-77 corridor and mostly out of the
CWFA. Afternoon highs should end up near-normal ahead of the front.

Behind the front, mostly Sunday evening and beyond, temperatures
will crash as very strong CAA accompany an Arctic surface high
that slides over the central CONUS. Much colder air will filter
in, while northwest flow precipitation picks up along the NC/TN
border. Freezing levels will lower quickly Sunday evening, so the
northwest flow precipitation will quickly turn to snow, especially
in the higher elevations (=>3500`). Hysplit model runs detect
a Great Lakes connection, which only upticks the northwest flow
snow overnight Sunday as the setup becomes dynamically enhanced
with strong vort lobes shifting over the region as model guidance
form a closed low within the trough. Some differ on how far south
the closed low actually drifts, but higher snowfall totals can
be associated with closer proximity of the closed low. All of the
deterministic guidance except for the GFS brings the low across the
CWFA, while the GFS keeps it to the north. Either way the setup
is a typical northwest flow event and should lead to lingering
snow showers into the daytime period Monday, especially in the
northwest facing slopes along the TN border and Smokies. Can`t
ruled out some light accumulations below 3500` into the valleys
before the event is over with by Monday night as these locations in
the mountains will be at or slight above freezing, with very cold
vertical profiles that suggest if anything were to fall out the sky,
that it will be in the form of snow. If the closed low sags far
enough south that it cross the area on Monday, don`t be surprised
to see a few snow flurries break containment east of the mountains,
with flurries possible across the foothills and Piedmont Monday
evening. The chance is low, but definitely nonzero. Snow
accumulations will vary, but the highest amounts are likely in the
northwest facing slopes of the Smokies and in the Roan Mountain
area, where 1-3" of snow is currently forecasted, with locally
higher amounts at elevations above 4500`. Less than one inch is
expected elsewhere along the NC/TN border for now until more
guidance from the CAMs come in on Saturday. Overnight lows Sunday
should end up 5-10 degrees below normal, with an uptick in winds and
wind gusts with the onset of CAA. Only Advisory criteria gusts exist
above 3500` at this time. That combined with the snow Sunday night
could create borderline blizzard conditions above 3500` along the
immediate TN border.

Continued northwest flow snow along the immediate TN border Monday,
while the rest of the area remains partly to mostly sunny. Despite
maximum insolation, anomalously cold thicknesses will be in place
as continued CAA filters in. In this case, temperatures will
run 15-20+ degrees below normal, with 20-30 degrees below normal
being possible in the mountains, making this the coldest air of
the season and feeling the middle of Winter across the western
Carolinas and northeast Georgia.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
As of 115 PM EDT Friday: The upper trough axis will be in the
midst of slipping across the CWFA Monday night as the surface high
over the Lower MS Valley and Deep South helps to relax the winds
and create an environment for really strong radiational cooling
conditions. Factor in very cold thicknesses still in place and
overnight lows will flirt with record low values across parts
of the CWFA, with the higher elevations in the single digits,
teens and twenties in the major mountain valleys, and twenties
for locations outside of the mountains, leading to a widespread
hard freeze that will kill any plant or vegetation that is left
standing outside. Will need a Freeze Watch for the active growing
season zones over the weekend, which is basically all locations
outside of the mountains. Drier air will filter in and the incoming
trough axis will essentially shutoff the northwest flow snow,
but wouldn`t be surprised if that still lingers half the night on
Monday in the favorable upslope regions.

Broad upper troughiness lingers through a good portion of
the rest of the week starting Tuesday as the airmass gradually
modifies. Tuesday should be the last really cold day as highs will
be in 40s over the mountains and 50s outside of the mountains. Model
guidance look to send another cold front during the middle part
of the week, but should be mostly moisture starved without a
real return flow out ahead of it. Otherwise, dry conditions
expected through the end of the workweek as temperatures return
to near-normal values by next Thursday and Friday.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: A band of low stratus continues to scatter
our across the area with all terminals expected to return to VFR
within the next hour or so. VFR conditions continue through the rest
of the day and into the evening ahead of an approaching cold front
from the west. A band of showers will accompany the front overnight
into early Saturday morning with temporary visibility restrictions
possible at all terminals. There are some indications that fog could
develop behind the showers prior to sunrise, but confidence is low
at this time as it will depend on timing of the rain and dissipation
of enough cloud cover for radiation fog to develop. If fog does
develop, some patches of dense fog cannot be ruled out. VFR
conditions return by mid morning Saturday and persist through the
remainder of the TAF period. Winds will be generally light out of
the southwest.

Outlook: Scattered showers may bring isolated restrictions through
the remainder of the weekend as another cold front approaches from
the west. Low clouds and precipitation may linger Monday across the
mountains. Dry conditions return Tuesday. Gusty winds develop Sunday
ahead of the second front and linger through Monday into Tuesday.

&&

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

&&

$$

SYNOPSIS...CAC
NEAR TERM...TW
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...TW