109
FXUS62 KGSP 211803
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
103 PM EST Fri Nov 21 2025

.SYNOPSIS...
A warm and increasingly moist air mass will remain in place over
our region through Saturday.  Rain chances will be highest over the
mountains as low pressure tries to organize to the west of our area.
Drier but mild high pressure will arrive on Sunday and persist
into early next week.  A cold front will cross the the area in the
middle of the week, ushering in much cooler temperatures behind it.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of noon Fri: Broad upper ridge centered over the eastern Gulf
and south Atlantic Coast today. Nebulous forcing persists through
the afternoon and evening over our CWA, with weak warm front or
baroclinic zone remaining north of the area across KY/VA, north
of the ridge. Said front is associated with a cyclone, now in the
central Plains, which will advance across the mid-MS Valley tonight,
inducing secondary cyclogenesis in the Mid-Atlantic by morning. A
modest cold front should be pulled across the Carolinas/Georgia
late Saturday or Saturday night in turn.

500mb vort axis, a wave preceding the aforementioned cyclone, now
seen on vapor imagery over eastern KY/TN, set to track across the
CWA as it dampens out this afternoon. Max temp potential looks to
be limited by the midlevel cloud cover lingering over the northern
CWA, but most of the Piedmont still makes it into the 70s (a few
degrees shy of records). A modest amount of SBCAPE is shown to
develop this afternoon, with prog soundings most supportive for
deep convection over the mountains. However, as a reflection
of the nebulous forcing, CAMs certainly are not excited and
depict paltry coverage. 20-40% PoPs are forecast over much of the
northwest half of the area through early evening. PWATs decline a
bit for a time this afternoon but increase tonight as cold front
approaches from the west. 850-700mb WAA also picks up, with some
elevated instability above the associated inversion. Hence all areas
receive at least a chance range PoP between about midnight and 5 AM;
a small chance of thunder is forecast in the SW NC mountains and
portions of the CWA southeast of I-85 overnight. Chances decline
east of the mountains by daybreak, as the moisture band shifts east,
but continue to increase along the TN border thru the morning due
to upslope westerly flow, before tapering off.

Gusty SW winds will develop Saturday as clouds scatter, and with
the further aid of downsloping aloft temps should reach the upper
70s in the Piedmont. Still forecasting a record high for CLT and
GSP although AVL still falls short Some showers could redevelop
east of the mountains during peak heating although dry mid to upper
levels likely would weaken deep updrafts. Fast 700-500mb flow will
persist aloft and 0-6km shear is accordingly impressive at 50-60
kt. The surface front arrives past peak heating, and the dry air
aloft is a limiting factor, so severe threat looks rather low,
but can`t completely rule out the ingredients coming together for
strong storms producing a straight-line wind and/or hail threat
in our eastern CWA in the mid to late afternoon.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 1143 AM EST Friday...

Key Messages:

1) Clear and quiet weather in store for Sunday and Monday.

2) Above-normal temperatures expected to persist.

3) Next system approaches from the west by late Monday.

Quiet weather on tap for the short term...as z500 troughing slides
to our east Saturday night...and ushers in somewhat clearer skies
overnight.  Some lingering mid/upper level moisture may persist
into the first part of Sunday, especially in mountain valleys.
By mid-day Sunday, however, a reinforcing shortwave axis will cross
the western Carolinas and scour out any remaining moisture...leaving
us dry and clear through Sunday night and into Monday.  Highs will
creep back toward normal, but the air mass pushing into the area
Sunday will already be well-modified by the time it reaches us,
so highs will remain above normal...just not as far above normal
as they have been.

Upstream, the latter half of the weekend will see a complex
split flow pattern develop over the western CONUS.  An upper low
initially located over the Four Corners region of the American
Southwest will open up into the mean flow by early Monday, but
should quickly be replaced by a new disturbance dipping down out
of west-central Canada.  The result will be cyclogenesis in the
lee of the Colorado/New Mexico Rockies, but generally slow eastward
progress of this low.  By Monday evening, some upper-level moisture
may return to the Carolinas - so perhaps expect some cirrus.  But,
the deeper moisture and associated active weather will remain well
to our west through the end of the period.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 1201 PM EST Friday: Significant timing differences among
long-range ensembles continue to plague a forecaster trying to
gauge what approaching low pressure will do mid-week.  The bulk
of operational guidance depicts an upper low deepening over the
central Great Plains on Tuesday, then pivoting eastward into the
Great Lakes and upper Ohio Valley, and steering an associated
cold front across Tennessee by Tuesday evening.  LREF membership
generally supports this timing.  The question becomes how quickly
the front will push east of our CWA.  The GFS and its ensembles tend
to favor a slower progression, where the upper low lifts northward
and the front only slowly meanders into the eastern Carolinas by
Wednesday night.  The ECMWF and GDPS, and at least the majority of
their ensembles, depict a much faster progression as a consequence
of a more open-wave-like upper pattern that maintains good steering
flow farther south.

Slower solutions would maintain some degree of synoptic forcing
with the frontal circulation well into Wednesday...and although
ongoing rain would likely inhibit good destabilization, some sample
forecast profiles from these solutions do support at least weak
surface-based CAPE Wednesday afternoon...which could allow some
embedded thunder.  The bigger imapct, however, still appears to be
rainfall...with areas west of I-26 potentially receiving up to an
inch of rain...or even more in isolated spots across the Smokies
and Balsams.  By all accounts, we need this rain, and given dry
antecedent conditions, we don`t expect widespread hydro issues
unless QPF response increases a good bit.

Behind the front, a cooler, drier air mass should settle into the
area.  Temperatures will trend back toward normal, and it should
finally start to feel like late November.  By Thursday and Friday,
highs will only climb into the mid-50s, and lows will drop below
freezing even across the low terrian.  Brrr!

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: KCLT reporting SCT low clouds and "HZ" at
issuance time but the HZ is probably drizzle, which could come and
go in early afternoon. Some portions of the northwest NC Piedmont,
including KHKY, remain under an IFR stratocu deck, but that should
become increasingly SCT with time. TEMPO IFR at KHKY for the first
hour. Otherwise, SCT low VFR cumulus and SCT-BKN altostratus thru
the afternoon. Winds will pick up from the SW this aftn and persist
overnight. -SHRA possible over the mountains this aftn but chance
too low to mention at KAVL. Best overall chance for the terminals
is overnight into early Saturday with elevated -SHRA in moist
environment ahead of approaching cold front. This is handled with
combo of VCSH and PROB30/TEMPO, with brief vsby restrictions likely
with any precip, and an isolated TS possible. During or after -SHRA,
MVFR to IFR cigs could form and linger thru daybreak. Winds remain
SW and become gusty in some spots prior to 18z Sat, except KAVL
which will flip to NW. Other sites turn NW at/after 18z. Isolated
SHRA or TSRA could develop near KCLT after 18z Sat as well, but
chance too low to mention at this time.

Outlook: Drier conditions return early next week, although there
will remain some potential for mountain valley fog/low stratus
each morning.

&&

.CLIMATE...
RECORDS FOR 11-21

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      76 1994     24 1937     60 1931     11 1914
   KCLT      78 1942     38 1937     64 1991     19 1914
                            1879
   KGSP      78 1942     38 1914     64 1991     17 1914



RECORDS FOR 11-22

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      74 1940     32 1937     57 1934     15 2008
                                                    1937
   KCLT      76 2011     38 1929     65 1883     13 2008
   KGSP      77 2011     38 1937     58 1953     18 1914

&&

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

&&

$$

SYNOPSIS...MPR
NEAR TERM...JCW
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...JCW
CLIMATE...GSP