926
FXUS62 KGSP 231047
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
647 AM EDT Sat Aug 23 2025

.SYNOPSIS...
Chance for showers and thunderstorms linger through the rest of the
weekend, ahead of a cold front. Can`t rule out an isolated instance
of localized flash flooding. The cold front is expected to pass
through the area on Monday, leading to a Fall-like airmass as drier
and cooler conditions settle in through much of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 635 AM EDT Saturday...Radar shows some isolated light
shower activity over the Lakelands at daybreak, generally moving
westward slowly. Expect the western Upstate/northeast GA/ and the
central/srn mountains of NC to see a few more tiny showers at any
time overnight as we retain some weak sfc-based buoyancy in those
areas to fuel the shallow convection being forced by an easterly
upslope flow. Temps will start out close to normal.

Still dealing with this weakness/baggy mid/upper trof across
the region for one more day before it gets absorbed into the
upper trof digging down from the Great Lakes/Midwest late
tonight. A low-amplitude mid/upper ridge over the northeast
continues to support relatively weak sfc high pressure off the
Mid-Atlantic/New England coasts today, ridging down across our
region in wedge look-alike fashion, but it`s really nothing more
than an inverted ridge because the static stability is too low for
cold air damming. Through peak heating, a moisture gradient will
be working its way westward across the region, so precip probs will
be much higher over the west and generally isolated at best east of
I-77. The lingering moisture and light easterly flow should be able
to generate scattered to numerous showers and a few thunderstorms
(over the mtns) this afternoon in an environment that might only
manage 500 J/kg of sfc-based CAPE, maybe 1000 J/kg closer to the
TN border. The lack of buoyancy should preclude much of any threat
of severe storms, and the heavy rain threat looks lower than it
has the past week or so. Meanwhile, the extensive cloud cover and
cooler easterly flow should once again keep high temps on the order
of 5-10 degrees below normal. For tonight, the plan is for any
remaining shower activity to get pushed further out to the western
and southern borders by the continued E/NE flow, leaving us with a
night more quiet than the past few. Low temps should be a category
or so below normal as some drier air advects into the region.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 132 AM EDT Saturday: Broad upper troughiness will begin
to dig into the southeastern CONUS as a strong closed upper
low churns just south of the Hudson Bay. An airmass changing
cold front will be just northwest of the CWFA at the start
of the forecast period. Some available moisture and a slight
uptick in deep layer shear (~20-25 kts) will be evident ahead
of the front. Model guidance are not excited about instability
developing with only 1000-2000 J/kg of SBCAPE. In this case, a
couple of organized cluster of thunderstorms can`t be ruled out
with one or two potentially becoming strong to severe, however,
the threat is low Sunday afternoon and evening. The front should
make a full fropa on Monday as noticeably drier air filters in
behind the front with dewpoints in the 50s across much of the area,
with some 40s in the mountains by Monday afternoon/evening. Sunday
will be the last real warm and humid day with afternoon highs a
few ticks below normal. Elevated dewpoints will keep overnight
lows near-normal Sunday night. Downsloping behind the front and
compressional warming ahead of the front will keep Monday on the
warmer side despite the fropa as this will help to delay the onset
of true CAA. Afternoon highs on Monday will continue to run a few
degrees below normal. The real cooldown will be felt Monday night
with overnight lows in the low to mid 50s in the mountains and
foothills, while lower 60s will be present in the Piedmont zones.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 137 AM EDT Saturday: Broad cyclonic flow aloft and falling
heights will keep the cooler and drier airmass in place through much
of the upcoming workweek. Surface high will settle over the area
from the northwest by Wednesday night, which should be the coolest
night with 40s in the mountains and 50s elsewhere before a very
gradual rebound in temperatures. We mean very gradual. Otherwise, a
mostly dry forecast with some potential of precip returning by the
very end of the week, but confidence is too low this far out for any
mentionable PoP outside of the ridgetops. Temperatures will be 6-12
degrees below normal through much of the period.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: We remain under a moist easterly low level
flow early this morning, so low clouds will be abundant, some of
which will form a temporary bkn ceiling at the MVFR level. Can`t
rule out some brief IFR at the Upstate terminals either, but the
IFR depicted in some of the guidance is much less certain. The TAFs
will stay optimistic at this point and keep most places at MVFR
at least temporarily until the middle part of the day. Wind will
be light ENE. The low clouds should be slow to lift and scatter
once again today. The atmosphere will not get nearly as unstable
this afternoon, but the moist easterly low level upslope flow will
persist. Thus, most terminals with the exception of KCLT have a
chance at showers in the afternoon. At this time, the wind direction
should come around to ESE for awhile. The shower activity should
diminish by sunset. Dry air will filter in from the east tonight,
limiting low cloud production.

Outlook: Shower and thunderstorm chances along with associated
flight restrictions will linger through the second half of the
weekend. Drier conditions will return next week. Fog and low
stratus may develop each night, mainly in the mountain valleys.

&&

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

&&

$$

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