910
FXUS62 KGSP 221043
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
643 AM EDT Fri Aug 22 2025

.SYNOPSIS...
Chances for mainly afternoon and evening showers and thunderstorms
increase into the weekend. Temperatures will be a few degrees below
normal Friday into the weekend. Temperatures warm up briefly Monday
ahead of a cold front before cooler and drier conditions develop
behind the front the rest of the workweek.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 645 AM EDT Friday...still have scattered showers
lingering across the western Piedmont at daybreak, but rainfall
rates and coverage are considerably less than what we saw
overnight. Meanwhile, other showers were slowly developing in the
weakly upslope flow over the foothills and near the Blue Ridge
Escarpment, as well as parts of the Upstate. Precip probs were
tweaked again to account for the radar trends. The remnant blob of
weak sfc-based CAPE has drifted to the south and over the Midlands,
so any remaining showers are not expected to cause major problems.

As for today, the idea is that we would have another fairly active
day in spite of widespread cloud cover because of this remnant
baggy mid/upper trof overhead and plenty of available moisture
to work with. The developing E/NE upslope flow at low levels will
easily force additional storms across much of the region, but this
doesn`t look like a widespread washout, more a case of most places
over the mtns/Upstate/northeast GA getting a round of rain and/or
thunderstorms at some point with some potential for heavy rain
through the evening. The Marginal Risk on the Day 1 ERO looks like
a good call. Meanwhile, some drier air should filter in from the
NE in the morning and much of the NW Piedmont may stay rain-free,
with the dry air making progress over the western Piedmont and
nrn Upstate in the afternoon. Tough forecast. Extensive cloud
cover and early precip will keep temps below normal, maybe by as
much as ten degrees in some spots. The southwest mountain valleys
of NC might end up the warmest, but if the sun peeks out for too
long the eastern zones could get warmer than fcst. For the evening,
the shower activity should linger along the old boundary draped to
our south and along the other weak boundary getting pushed slowly
SW into northeast GA. Several of the CAMs depict this scenario,
with the rain continuing over northeast GA and the western Upstate
until the pre-dawn hours. Low temps should be in the upper 60s
outside the mtns, so a bit cooler than what it has been lately.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
As of 1207 AM EDT Friday: A quasi-stationary frontal boundary will
be draped south of the CWFA, while a surface high shifts offshore
the Mid-Atlantic Coast. Expect a stout Atlantic Fetch to provide a
moist airmass across the area, especially in locations along and
west of I-26. With scattered vort energy in place, aiding in an
obvious lifting mechanism, expect numerous to widespread convection
across the aforementioned area on Saturday. Instability will be
limited as profiles show tall, skinny CAPE, and deep warm cloud
layer, while PWAT values are able to surge up to 1.50"-2.00".
Without much in the way of wind shear, storm motion will be
relatively slow and could lead to a few instances of localized flash-
flooding. The convective activity will have an enhanced diurnal
peak, but with available forcing and moisture, expect convection to
linger past the typical diurnal timeframe and continue into the late
evening and early overnight period, while gradually diminishing in
coverage. Drier air punching in from the north-northeast at the
surface should help contain this activity from spreading too far
east of the I-77 corridor. Temperatures should run 5-10 degrees
below normal thanks to extensive cloud cover and convection, but the
I-77 corridor should end a few degrees warmer compared to the rest
of the Piedmont zones, where insolation at the surface will be
better. Lingering convective debris and a relatively moist airmass
will keep overnight lows near normal for Saturday night.

A weak surface low will develop along stalled frontal boundary
and lift up the Carolina Coast Sunday into Sunday night, while
a stout upper trough begins to dig into the area from the north
with a Fall-like cold front knocking on our door. The surface low
should provide some surface subsidence to help with widespread
convective development, especially east of the mountains. However,
the front will bring its own lifting mechanism with enough
moisture to initiate convection over the mountains during peak
heating Sunday. Orographic enhancement will also play a role in this
development. With a slight uptick in deep layer shear, height falls,
and available instability, can`t totally rule out a sneaky severe
storm or two in the mountains/foothills for Sunday. The activity is
shown moving across the CWFA Sunday night as the cold front slowly
pushes into the CWFA, making a full fropa right at daybreak Monday
or slightly after the forecast period. Very noticeable changes coming
to you in the extended forecast period. Temperatures will be a few
ticks below normal for afternoon highs on Sunday and near-normal
Sunday night.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 1232 AM EDT Friday: Strong cold front with height falls
will make a full fropa by Monday afternoon, with stout dry air
advection behind the front. A Fall-like pattern will be in store
for much of next week as a result. Broad cyclonic flow aloft
will remain in place through much of the forecast period over the
eastern CONUS as convection is essentially shutdown and dewpoints
fall into the 50s and even 40s across the higher elevations. The
onset of cooler air won`t filter in until Tuesday, so Monday will
be the last really warm day, with highs only being a few degrees
below normal. Temperatures beyond Monday will be 5-10+ degrees
below normal for afternoon highs and overnight lows. Expect the
muggy conditions to come to an end at least through the last days
of August.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: A real mixed bag of flight restrictions
early this morning because of showers and storms persisting in
the weakly upslope flow east of the mtns. The idea remains that
we will develop low cloud decks readily around daybreak, mainly
low MVFR and IFR. Wind will be light NE to E. After sunrise,
the ceiling will slowly lift with daytime heating to MVFR. Most
locations will stand a decent chance of getting another round of
thunderstorms at some point from midday onward. The exception will
be KCLT, where dry air will work in from the east. The convection
may linger over the mtns/western Upstate/northeast GA well into
late tonight. The situation doesn`t change appreciably tonight,
so more ceiling restrictions can be expected at most terminals.

Outlook: Shower and thunderstorm chances along with associated
flight restrictions will linger through the weekend.  Drier
conditions will return next week.  Fog and low stratus will be
possible each morning.

&&

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

&&

$$

SYNOPSIS...AR
NEAR TERM...PM
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...PM