Area Forecast Discussion
Issued by NWS Greer, SC

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
274
FXUS62 KGSP 081811
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
111 PM EST Sat Nov 8 2025

.SYNOPSIS...
A few strong to severe thunderstorms can`t be ruled out this
afternoon and evening across portions the western Piedmont. 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 SUNDAY/...
As of 1240 pm Saturday: The latest water vapor imagery depicts a
very broad/low-amplitude upper trough centered just east of the Miss
River Valley early this afternoon, with a train of mostly weak short
wave short wave troughs from the Ohio Valley NW into the Canadian
Prairie. Surface analysis depicts a weak/quasi-stationary frontal
boundary bisecting our CWA, with slightly warmer/clearer conditions
indicated south of the boundary...roughly across the southern half
of the area. The latest SPC Mesoanalysis indicates 500-1000 J/kg of
sbCAPE from the Lakelands/upper Savannah River Valley into north
GA, with cumulus becoming increasingly congested/agitated across
north and central GA.

Convection-allowing models remain consistent in allowing scattered
deep convection to develop along/south of the boundary...from
central GA into the southern half of our area by late afternoon,
continuing into the evening as mean cloud-bearing flow allows
activity to move rather quickly E/NE toward the Charlotte
Metro Area. Deep layer shear will be more than adequate for
organized cell structures, including the potential for rotating
updrafts/supercells in the more unstable air (e.g. across the
southern tier of our counties.) The main severe threats would be
from large hail with any rotating storms, as well as damaging wind
gusts. Low level shear/helicity parameters are quite underwhelming,
but a brief, weak tornado cannot be ruled out with any supercell
structures. Scattered convection will move east by around
midnight...or shortly thereafter, with another round of widespread
low clouds and fog...perhaps locally dense expected by daybreak. Min
temps will be well above normal in the cloudy/humid conditions.

The upper trough will continue to deepen/amplify as it
approaches the Appalachians on Sunday, with attendant strong
cold front forecast to push into western North Carolina by
late morning...pushing east of the CWA by the end of the
period. Temperatures will begin falling across the mountains
during the afternoon, with northwest upslope flow becoming
established...and attendant scattered showers expected...especially
across the counties bordering TN. Rain is expected to change to snow
above ~4000ft by the end of the period as snow levels steadily fall
in the strong cold advection. Other than the NW flow precip...the
front is unlikely to bring any showers to the forecast area, as
moisture and forcing are expected to become maximized to our east.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 1258 PM EDT Saturday: Strong CAA and steep height falls will
be in the midst of entering the CWFA as a digging upper trough parks
over the MS Valley and the attendant cold front should be in the
process of exiting the eastern portions of the CWFA by the start
of the forecast period. Low-level flow will turn west-northwesterly
with strong vort lobes traversing across the area and moisture being
advected off the Great Lakes. This combined with tanking snow levels
and mechanical lift along the NC/TN border, expect northwest flow
snow to crank up overnight Sunday. Tight pressure gradient (4-6mb)
with ongoing snow and dynamical features aloft will support sporadic
blizzard conditions at the highest elevations (>4000`) along the
immediate Tennessee border. Soundings from the CAMs are picking up
on very shallow instability, which should only increase snowfall
rates, especially in the favorable upslope areas in the Smokies,
northern Madison County, and the Roan Mountain area. Perhaps an
instance of thunder snow can`t be ruled out either, but good luck
finding the exact location where this might occur. The rest of
the area remains quiet, but the CAA will uptick winds overnight
Sunday. Despite temperatures getting close to freezing and matching
up well with frosty values outside of the mountains, winds will be
elevated too much for frost to develop and will keep temperatures
too warm for a Freeze Warning. Overnight lows on Sunday will run
5-10 degrees below normal.

Northwest flow snow will linger throughout the day Monday, but will
be off and on as the area will be in between two large areas of vort
energy. Downslope flow should help locations outside the NC/TN
border to remain partly to mostly sunny, especially during the first
half of the daytime period. Some changes will be noticeable by the
evening hours as a bowling ball of vort energy associated with the
closed upper low swings into the area. Enough dynamical forcing and
low snow-levels could allow for the reinforced northwest flow snow
to break containment east of the mountains depending on the
orientation of the low. This provides an AFD mention for possible
flurries across the western Piedmont and foothills and Upstate SC,
but confidence is not high enough for a mentionable PoP. Seems like
model guidance are in good agreement with the placement of the low
and the timing happening after peak heating to allow for such setup
to occur. Flurries will not be widespread, but a few locations may
get lucky enough to see November flakes outside of the mountains.
This will also be the best time period for some of the other
mountain locations that don`t normally feel the impacts of northwest
flow snow to get in on the action as well, with little to no
accumulation expected in the locations outside of the typical west
to northwest facing slopes. With the impressive dynamics of this
system and the Great Lakes connection, will not be surprised to see
snow totals exceed expectations in some of the ridgetops and favored
upslope areas. With that being the case, the latest snow totals
match up well with the overall thinking and supports 6-10" at the
highest elevations in the Smokies, and a solid 1-3+" along the
immediate Tennessee border, with less than an inch elsewhere.
Temperatures will be cold on Monday as afternoon highs will be
colder than what we receive in the middle of January. Afternoon
highs will run 15-20+ degrees below normal.

The bowling ball closed upper low should shift east of the area by
daybreak Tuesday as dry air entrainment gets going and essentially
shuts off the northwest flow snow maker. The coldest night of
the season will be Monday night as CAA fully settles in and very
cold thicknesses remain in place. Expect a hard freeze across
the entire CWFA with most locations in the 20s, teens and single
digits expected for the higher elevations. In this case, all of the
non-mountains zones should expect a Freeze Warning Monday night
into Tuesday morning. Factor in the elevated wind gusts and the
wind chill values will be near or below 0F above 4500`, with single
digits in the lower elevations, and teens for a large area outside
of the mountains. Doesn`t meet Cold Weather Advisory, but will be
close. The trough axis shifts east of the area on Tuesday and a
strong surface high will settle over the eastern half of the Gulf.
Expect drier conditions and mostly sunny skies, with a gradual
rebound in temperatures, but not much. Afternoon highs on Tuesday
will continue to run 12-18 degrees below normal.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 106 PM EDT Saturday: Broad upper troughiness should
linger overhead through a good portion of the workweek as the
airmass continues to modify Wednesday and beyond. Model guidance
continue to hint at a relatively diffuse cold front to move in
Thursday associated with a passing shortwave over the northeastern
CONUS. Expected to be moisture starved though as no real return flow
and weak forcing won`t be able to squeeze much of a QPF response
across the CWFA. However, a reinforcing shot of drier air behind the
front may cause some fire weather concerns Thursday and Friday as
this will lower RH values. Otherwise, dry conditions are expected
as temperatures return to near-normal or slightly higher values
by next Thursday and linger through the end of the forecast period.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Cigs have finally scattered and/or lifted
to VFR across the Terminal Forecast Area this afternoon, although
can`t rule out brief periods of MVFR here and there for the first
couple of hours of this forecast period. Meanwhile, moisture will
remain adequate for some modest destabilization to occur in light
of the strong heating that is underway, especially across the
southern half of the area. A weak frontal boundary is expected to
provide a focus for development of scattered deep convection late
this afternoon into the evening...mainly impacting the upstate SC
terminals and KCLT. Convection should primarily be of the shower
variety, but isolated/widely scattered thunderstorms are expected,
with the probability of such increasing toward the southern part
of the area...such that a tempo for TSRA is included at KAND after
22Z. VCSH and/or Prob30s for SHRA appear to be the best forecast
at the other terminals, but will need to monitor trends closely for
potential AMD to include TS at the other Upstate terminals and KCLT.

Convection is expected to diminish and/or move east of the
area around, or shortly after midnight, with the potential for
crashing cigs and possibly reduced visby increasing from late
evening through the overnight. LIFR cigs are forecast at most
sites between 06-12Z Sunday. The visby forecast is primarily MVFR,
but can`t at all rule out something lower, especially at the NC
terminals. Skies should clear at most terminals by late morning,
with VFR expected at most sites from ~15Z on. Winds will generally
be light/variable until the daylight hours Sunday, when they are
expected to become SW at 5-10 kts at most sites, with a further
increase and some gustiness expected Sunday afternoon.

Outlook: A strong cold front will cross the area from the west
by late Sunday, bringing gusty winds, some low clouds and RA/SN
showers to the mountains.  Precipitation may linger Monday across
the mountains. Gusty winds linger through Monday into Tuesday. Dry
conditions Wednesday and Thursday with afternoon gusts possible.

&&

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

&&

$$

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