476
FXUS62 KGSP 021119
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
619 AM EST Tue Dec 2 2025

.SYNOPSIS...
Low pressure lifts across the forecast area today bringing
widespread precipitation. Behind the system, high pressure will
result in chilly and dry conditions Wednesday into Thursday.
Unseasonably cold and unsettled weather is expected Friday as
another system brings more precipitation to the area.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 614 AM EST Tuesday...

Key Messages:

1) Winter Weather Advisory remains in effect for the northern and
central Appalachians, owing to ongoing freezing rain and light
ice accumulations, until 10 AM.

2) Rainfall will continue through the first part of today before
we dry out during the afternoon and evening.

3) Dry but very cold conditions should return tonight.

Widespread rainfall still underway across the entire area, with
best coverage and rates across the SC Upstate; this continues to
drive patchy fog and low ceilings.  Lots of reports of icing across
the northern and central Appalachians this morning.  The peak
in freezing rain coverage has likely passed at this point, as
mesoanalysis now depicts the stronger signal for isentropic ascent
to our north and east, and temperatures are more or less holding
steady and even rising in some spots.  Would expect them to begin
rising everywhere, slowly but steadily, in the next 2 hours or so.
A Winter Weather Advisory remains in place for the southern French
Broad Valley, northern Blue Ridge, and NC Blue Ridge Escarpment
zones through 10 AM today, by which point temperatures at even
the coldest spots should be reliably warm enough to preclude
further ice accumulation and convert remaining precipitation to
an entirely-rain forecast.

Rainfall will move steadily eastward through late morning...with
essentially the entire forecast area forecast to be dry by early
afternoon.  Cloud cover could linger through much of the day, but
the influence of WAA across the area will help offset any loss
of daytime heating; high temperatures are therefore expected to
reach the low 50s across the non-mountain zones, only remaining in
the 40s across the NC mountains.  By tomorrow evening, we should
see consistent clearing that`ll continue into Tuesday night.
Between a somewhat cooler postfrontal air mass in place tomorrow
night, and a few hours of good radiative cooling after midnight
once CAA abates and winds die down, lows Wednesday morning are
likely to drop into the mid-20s across most of the low terrain,
except for the Savannah River Valley, which may hover around 30.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
As of midnight Tuesday morning:

Key message 1: Dry weather Wednesday with temperatures trending
slightly cooler in most Piedmont locations.

Weak sfc high pressure will migrate across the Southeast Wednesday,
though 500mb flow already will be slightly cyclonic as the next
trough digs into the northern Great Lakes region. Despite sunny skies
weak CAA continues and max temps will be held 2-3 degrees cooler than
Tuesday in most locations east of the mountains, the greatest change
being in areas that experience strong downsloping/warming Tuesday
afternoon. Temps will be about the same within the mountains or
perhaps slightly warmer.

Key message 2: A weak front settling through the area Thursday could
spawn a few showers in our far south, and should bring cooler temps
to the mountains and warmer temps east.

Dynamic forcing with the aforementioned trough will remain far off to
our north through Thursday, and the associated front looks to reach
the CWA with minimal oomph. Midlevel cover will reach the area early
in the day which will limit warming in the mountains, with CAA
developing there during the day also. With the previous airmass
modifying, and with downsloping beginning aloft with the arriving
front, temps should trend slightly warmer east of the mountains.

The sfc high behind the front expands east out of the mid-MS Valley
by the end of the day Thursday. The front in turn should stall along
its southern periphery somewhere across GA/SC. Meanwhile a separate
shortwave will exit the southern Rockies and begin to activate the
previous stalled/coastal front in the far Deep South. It is hard to
discern which front is responsible for the small PoPs depicted by
some models over our Lakelands zones, but the idea is plausible
enough for a slight chance in the official forecast, as rain Thursday
afternoon.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 1230 AM Tue:

Key message 1: Confidence remains very low in the forecast for
Thursday night through Saturday night, but period(s) of light wintry
precip cannot be ruled out in that timeframe, mainly in the northern
CWA.

General expectation is the same as previous cycles, that the surface
high that reaches the area Thursday will center over the Mid-Atlantic
coast by Friday morning, and that amplifying jet streak and/or the
weak trough crossing the southern Rockies will lead to frontogenesis
along the baroclinic zone across the SE Coastal Plain to our south.
The timing of that process, causing eventual development of a
Miller-A cyclone, however remains difficult to pin down.

Cold-air damming had seemed like a good bet given the strength and
position of the high, but recent GFS runs show the high being weaker
and more transient, with less diabatic cooling and later onset of PoP
which would suggest precip is likely to begin as rain for all but the
coldest Escarpment areas. The ECMWF, which had once been consistent
in Friday being dry, is now faster and colder than the GFS, clearly
depicting CAD and freezing rain and/or snow over our northern
mountains and I-40 corridor. With the wedge locked in, it continues
to produce some wintry precip through Friday. The GFS eventually does
produce QPF in a similar pattern, just starting later and almost all
liquid. The Canadian GDPS is drier, showing a weaker high like the
GFS but also keeping the precip associated with the frontal wave
mostly to our south. The best consensus for precip occurrence is
Friday afternoon through very early Saturday morning, and at least
weak CAD appears likely, even if temps remain above freezing. Temps
Friday look to be quite chilly. with most areas in the lower 40s,
possibly not making it out of the 30s if the CAD is as strong as the
ECMWF depicts. Regardless of which solution verifies, precip chances
should be on the decline east of the mountains, at least temporarily,
late Friday night as the Miller-A forms and pulls away from the
coast. Northwest flow snow or rime ice could develop near the TN
border at that time.

It remains unclear whether the aforementioned southern shortwave will
phase with another shortwave in the northern Plains, so there could
be another opportunity for coastal front to reactivate Saturday
night, exemplified by the 02/00z ECMWF. The GFS had once depicted
this sort of thing. PoPs do ramp back up as a nod to this
possibility. P-type in this scenario probably would be predominantly
rain, but more FZRA can`t be ruled out in the mountain/foothill
locations where colder temps persist. Temps should rebound back into
the upper 40s or lower 50s Saturday--still several below normal.

Key message 2: Light northwest flow snow is possible near the TN
border late Sunday thru early Monday.

Most models depict a clipper-like shortwave blowing across the
Appalachians between late Sunday and Monday morning, and small PoPs
redevelop near the TN border. Temps appear supportive of snow at that
time. The GFS depicts some light snow showers developing in the NC
Piedmont Monday morning but those often don`t pan out with a clipper,
or end up just being flurries and a novelty. Temps trend slightly
cooler again on Monday.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Widespread IFR ceilings with even some LIFR
mixed in this morning, with ongoing rainfall across most of the
terminal forecast area.  Signal remains in statistical guidance
for worsening vis as rainfall continues, and a period of overall
worsening restrictions to consistent IFR/LIFR around daybreak.
Vis should begin improving by mid-morning, but ceilings will
be much more stubborn, with the GLAMP and short-range blended
guidance both suggested that KCLT and the Upstate sites could
remain socked into IFR conditions well past noon today, despite
rainfall ending everywhere by late morning or early afternoon.
Could be well into the late afternoon/evening hours before enough
low-level moisture is scoured out enough to get us fully back
to VFR.  Light and variable winds overnight, at least somewhat
favoring an ENE component, will gradually become more consistently
NW by mid-day Tuesday.  Expect VFR conditions and a steady NW wind
of 5-7 kts the first part of Tuesday night, and for winds to then
become light and <3kts across the terminal forecast area during
the predawn hours Wednesday.  In some statistical guidance, there
is a weak signal for some mountain valley fog with any low-level
moisture that fails to scour out today, so threw in a mention of
MVFR fog at KAVL after 09z tonight.

Outlook: Dry, VFR conditions expected to persist through Wednesday
and the first part of Thursday.  Rain could return as early as
Thursday afternoon, but more likely Thursday night and Friday as
the next system arrives.  Rain and associated flight restrictions
could continue into the weekend.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Winter Weather Advisory until 10 AM EST this morning for
     NCZ033-049-050-053-065-501-503-505-507-509.
SC...None.

&&

$$

SYNOPSIS...AR
NEAR TERM...MPR
SHORT TERM...JCW
LONG TERM...JCW
AVIATION...MPR