225
FXUS62 KGSP 282341
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
741 PM EDT Sun Sep 28 2025

.SYNOPSIS...
A stalled front along the Carolina coast will drift west slightly
allowing for a return of showers and storms for Monday into
Tuesday. Meanwhile, a tropical system will drift northward across
the Bahamas, but is expected to slow down and start to drift east
away from the Florida coast late Tuesday. The tropical system is
expected to move further out over the Atlantic later in the week
as high pressure builds over our area from the north.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 735 PM EDT Sunday: Lingering upper troughiness to go along
with a light low-level Atlantic Fetch is helping to keep enough
available moisture around, which is resulting in a few showers
lingering over the mountains this evening, with not much breaking
containment east. Showers should dissipate prior to midnight. Drier
northeasterly flow continues to filter in at the surface thanks to
a surface high parked over the Great Lakes region. Nice day overall
with highs near-normal. Changes begin to take place overnight as
the aforementioned trough retrogrades and moist easterly low-level
flow in association with Tropical Storm Imelda works into the
CWFA from the east. CAMS continue to show the leading edge of the
precipitation where the flow veers from northeasterly at the surface
and easterly around the 850mb-700mb layer, creating a defined
convergence zone. Showers are expected to spread from east-to-west
starting early morning Monday near the I-77 corridor, then towards
the mountains by late morning/early afternoon. Not expecting much
in the way of instability as a wedge configuration settles in as
continued northeasterly flow sets the stage for it. Precipitation
will linger through a good chunk of the day. QPF amounts remain
on the lighter side with most locations receiving less than 0.50"
through the end of the forecast period. Expect afternoon highs on
Monday to drop a category or so compared to today.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 110 PM EDT Sunday: Moisture spreading in from the east
across a stalled front along the East Coast will be at its maximum
over the CWFA Monday night. This will be thanks to easterly flow
between T.D. Nine (which may be Imelda by that time) and high
pressure over the Great Lakes to southern New England. PoPs will
range from low-end chance in the far western zones to likely east
of I-77. From there the tropical system is forecast to slow down
and begin to turn toward the east. The latest guidance is in good
agreement on this, and the trend has been for this turn to be
further south of the Carolina Coast. Once that happens, flow will
turn more northeasterly atop the forecast area advecting drier
air and allowing PoPs to taper off. Scattered diurnal convection
looks to develop again Tuesday with the lingering moisture, but
then PoPs drop off Tuesday night. QPF doesn`t look heavy with this
precip, as forcing will be weak. Wednesday`s fcst has trended
drier, as high pressure builds in from the north. Mostly cloudy
skies expected Tuesday into Tuesday night, then turning partly
cloudy Wednesday. Breezy NE winds are expected both days across
the Piedmont, but well short of advisory criteria. Lows will be
5-10 deg above normal and highs a few deg below normal.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 130 PM EDT Sunday: The medium range looks pretty quiet for
the region, as guidance is in good agreement on a 1030-1033 mb sfc
high drifting south out of Canada into the Northeast, shunting
any tropical moisture off the East Coast. PoPs remain below 20%
thru the end of the workweek and temps will be a few deg below
normal. Overall, a nice fall air mass should spread over the
area. Models are not in great agreement on depicting a cut off
low developing somewhere around the lower MS Valley late in the
week. The 00z ECMWF is more bullish on the low spreading moisture
back into the CWFA late Saturday thru Sunday. Upper ridging will
hold on along the East Coast, but moisture may start to increase
from the west, if the low does form. For now, PoPs increase to
slight chc to low-end chc, with temps returning to near normal.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: VFR conditions are expected to persist
through much of the night...except in the mountain valleys, where
some fog/low stratus is expected to form after midnight. Having said
that, lack of widespread rainfall and slightly drier near-surface
air should result in restrictions being less widespread than on
Sunday morning. Additionally, VFR clouds may persist in the vicinity
of KAVL through much of the night...which would further limit the
probability of low fog/stratus. As such, have limited the mention
of restrictions to MVFR, with SCT004 clouds at KAVL by daybreak.

Otherwise, a plume of deep Atlantic moisture is expected to
advect into the Terminal Forecast Area from the east, mainly
after sunrise Monday. This will be accompanied by lowering cigs
as well as increasing chances for showers. MVFR cigs are expected
to develop at all sites by noon, with further deterioration to
IFR cigs expected...beginning late morning at KCLT...with most
other sites following during the afternoon. At this point, a
shower mention is limited to Prob30s/VCSH, but tempos may become
necessary once confidence increases in timing. A few TS are also
possible, but coverage is expected to be isolated and unworthy of
a TAF mention at this time. Winds will generally remain NE through
the period...5-10 kts through most of Monday morning, with some
increase...along with potential gusts possible during the afternoon.

Outlook: Some flight restrictions can be expected during the
early part of this week as a prolonged easterly flow at low levels
brings moisture westward. Most likely this will be in the form of
a low cloud ceiling at MVFR or IFR levels. Beyond that, confidence
in precip is fairly low. Over the mtns, fog and low stratus are
possible each morning, mainly in the mountain valleys and for any
locations that received heavy rainfall the night prior.

&&

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

&&

$$

SYNOPSIS...ARK
NEAR TERM...CAC/JDL
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...JDL