038
FXUS62 KGSP 030003
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
803 PM EDT Tue Sep 2 2025

.SYNOPSIS...
High pressure remains centered along the East Coast through
Wednesday. Conditions will be mostly dry with the exception of
mountain and foothill showers and storms returning on Wednesday. A
weak cold front approaches from the northwest on Thursday and may
bring another round of showers and storms to the area. Temperatures
remain below seasonal normals through Thursday. An upper ridge may
build eastward from Texas over the weekend resulting in a warming
trend until Sunday when another cold front brings cooler
temperatures into next week.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 745 PM EDT Tuesday: It is probable that scattered showers will
continue to percolate across the NC/GA mountains into the night,
aided by subtle energy rotating in within the cyclonic flow aloft.
Considerable cloud cover over the mtns will keep low temps about a
category warmer early Wednesday compared to today, but still about a
category below normal for early Sept.

Otherwise, the eastern half of the CONUS will remain under very
broad upper trofing thru the near-term period and beyond. Another
upper shortwave will move thru the longwave trof axis tonight and
support lingering mid clouds and sct precip across the mtns once
again. At the sfc, the weak wedge pattern over our area will
gradually dissipate thru the period as the sfc high weakens and
shifts further NE. The 850mb flow will become more SWLY across the
NC mtns later tonight/overnight, adding a weak upslope component and
increasing the shower potential. There is some weak instability in
the model profiles, but I`m not confident it will be enough to
produce any lightning over our fcst area tonight/overnight. Tomorrow
we will likely see better shower/tstorm coverage across the mtns and
into the foothills as the upper shortwave provides additional
support. Over the Upstate and Piedmont, precip chances tomorrow
appear mini-mal again. Temps will continue to warm on Wednesday, but
highs are still expected to remain below climatology, especially
over the mtns.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 113 PM Tuesday: The trend of the model guidance is toward
lifting the upper low from the upper Great Lakes north toward Hudson
Bay on Wednesday night and Thursday. and as a result, it is looking
less like an approaching sfc front will make it across the mtns in
spite of some decent-looking mid/upper forcing. The main concern
for Thursday will be the severe weather threat. The new model runs
show less of a push and keep the front to the northwest through
the day. Only the NAMNest goes out far enough to give clues, and
it supports the idea that precip probs would be limited to the
area N/W of I-85, but a little more expansive than what the NBM
shows, so precip chances have been extended into the NW Piedmont
zones. The better shear and buoyancy is expected to stay on the
west side of the mtns, but at this point severe storms will not
be ruled out, especially in northwest NC. Temps ahead fo the
boundary will rise back to normal for Thursday. The passage of
a short wave will take the forcing with it, leaving the front to
the northwest for Friday, and keeping a brisk WSW low level flow
of warm advection. Friday looks dry, with temps climbing another
five degrees or so, above normal.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 1249 PM Tuesday: The forecast from Saturday onward seems
to be more and more of a slowly moving target as the guidance is
having trouble with the movement/timing of the large upper low
over eastern Canada over the weekend, and the evolution of what
remains of what is currently TS Lorena in the eastern Pacific. The
trend has been toward putting the center of the upper low farther
north with each run, which results in less troffing over our region
over the weekend, and thus less of a southward push for the second
sfc front. Thus, it`s looking more likely that a clean pass won`t
happen and the boundary, such as it is, will get hung up across the
region at least on Saturday and Sunday, possibly into Monday. There
would be enough modest instability across the mtns on Saturday to
account for some thunderstorm activity, though the better shear
would remain to the west and northwest, minimzing the severe storm
potential. Precip chances are trending back upward for the back
half of the weekend, though still below 30 pct across most of the
region. Temps also don`t cool off quite as rapidly on Sunday as
well. So, we continue to carry high temps on Saturday that are on
the order of 5-7 degrees above normal, but the dropoff to Sunday
is merely back to right around normal. The model blend continues
to favor a dropoff below normal for Monday and Tuesday, but the
model trend suggests that perhaps that is too low. By Tuesday,
confidence drops way off as the forecast guidance might not be
properly taking into account the fate of what becomes of the east
Pacific tropical system. The operational GFS is most bullish with
bringing a return of moisture from the southwest, but the ECMWF
is much more muted with a strong high to our northeast. For now,
a token chance is carried over the southern half, but that could
easily go either way.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
At KCLT: Under a light easterly wind, just some cirrus is expected
this evening. Higher level clouds may thicken at times into
Wednesday morning as upper level impulses rotate in.  Light winds
will assume a southerly component Wednesday afternoon along with a
VFR level cumulus field.  Shower chances are expected to remain well
west of the terminal tomorrow.

Elsewhere across the FA:  VFR conditions will continue for the
foothill terminal locations, with ongoing shower chances and
possible flight restrictions in the NC mountains.  It is far from an
ideal fog setup for KAVL thanks to considerable cloudiness and
shower possibilities.  Given the mixed signals on potential IFR
development, planning on staying the course feature at least chances
of IFR during the pre-dawn hours.  Also will maintain VCSH into the
night with PROB30s for tsra all Wednesday afternoon.

Outlook: At least sct aftn/evening convection will be possible
across the higher terrain on Thursday with chances diminishing again
on Friday. Nocturnal fog and/or low stratus will also be possible
overnight and into the morning, especially in the favored mtn
valleys.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...CSH/JPT
SHORT TERM...PM
LONG TERM...PM
AVIATION...CSH/JPT