027
FXUS62 KGSP 181759
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
159 PM EDT Sat Oct 18 2025

.SYNOPSIS...
Dry conditions continue today, before a cold front arrives
on Sunday, bringing showers and a few thunderstorms with it.
Dry and cool conditions return next week, lingering through next
weekend.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of midday Saturday: Breezy southwesterly flow will continue
this afternoon and tonight between sfc high pressure drifting
off the Southeast Coast and amplifying upper trough moving thru
the mid-Mississippi Valley. Pressure gradient should increase in
low levels overnight, and the SW flow should be associated with
some moistening, although even the normally more cloud-sensitive
guidance is not developing much cloud cover even along the Blue
Ridge Escarpment until very late tonight. Hence winds may weaken via
decoupling for a time in the evening, but probably will strengthen
again in the wee hours of the morning. Combined with the arrival
of cirrus around then, river/mountain valley fog is likely to
be at least as limited in coverage as it was Saturday morning,
and min temps will be even warmer, on the order of 10 above normal.

The trough will induce cyclogenesis near the Ozarks this evening,
with the incipient low reaching Michigan by morning. Given 40-50 kt
of cloud-layer shear largely oriented near parallel to the attendant
cold front, a linear MCS appears likely to form near the MS River,
pushing east thereof by midnight. This initial line looks to run
out of surface-based instability overnight, with loosely organized
weak convection reaching the western Smoky Mtns, possibly 6-8
AM if the line progresses faster than CAMs as frequently occurs,
but most likely not until 8-10 AM. Light precip chances expand east
across the CWA from there. Wind gusts of 25-35 mph will be possible
in the early morning over the mountain ridges, preceding the front.

Surface cold front will be west of the Appalachians, probably
over the Cumberland Plateau, around midday Sunday. A narrow zone
of viable SBCAPE is progged to develop ahead of the front as it
moves across East TN with shear parameters similar in magnitude
if not stronger to those seen overnight. Models largely develop a
second narrow band of convection there but differ as to how well
it holds together across the mountains. 12z HRRR depicts the line
maintaining organization and suggests further destabilization
by 19-21z immediately along the front across NE GA, the western
Upstate, and the NC foothills to the tune of 250-750 J/kg. Lapse
rates are still not very good through a deep layer, so how much
shear to which parcels are exposed appears somewhat questionable,
and this may partly explain why the same HRRR run depicts no
appreciable updraft helicity. A second round of showers perhaps with
isolated embedded thunder does look likely to develop and affect
the eastern half of the CWA. Winds look to easily gust to 30-35 mph
(perhaps locally up to 40 mph) at times during the afternoon in
these areas, and certainly a damaging convective wind event can`t be
ruled out. SPC MRGL risk area for wind looks reasonably placed given
the best forcing from the trough. One might argue the widespread
sub-severe gusts could prove more of a public impact. After somewhat
of a lull in the morning due to weakening LLJ, gusts will develop
across the mountains again behind the front and similarly could
gust 25-35 mph in the late afternoon and early evening.

Max temps Sunday will be limited by the earlier arrival of clouds
and precip in the western half of the area, and probably near
to a little below normal for the mountains and foothills. The
I-77 corridor still looks to rise into the mid-upper 70s or 2-4
above normal.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Key Messages:

1) Dry conditions persist with no rain expected.

2) Gusty winds return Tuesday ahead of another cold front.

As of 120 PM EDT Saturday: By Sunday night, there could be a few
lingering showers and thunderstorms moving through with the cold
front. However, these should quickly diminish and taper off as much
drier air from the N/NW filters into the region. Once the showers
move out, the pattern becomes dry and quiet once again. Surface high
pressure amplifies over the region and suppresses any rain chances
through the period. Synoptically, the southeast remains in
relatively zonal flow as a new upper low forms over the Midwest on
Tuesday. This disturbance deepens and swings over the Great Lakes by
late Tuesday, pushing another cold front toward the CWA. Ahead of
the front, guidance shows the western fringe of the high pressure
shifts closer to the area, allowing for a narrow window of moisture
advection. But this may not be enough of a recovery to allow for any
potential pre-frontal shower activity before even drier air comes
crashing in. All in all, Winds start diminishing on Monday before
picking up again Tuesday as the upper low shoves a compacted
pressure gradient to the north. As for any fire weather concerns, RH
levels look to be in the 30-40 percent range east of the mountains
on both days during the afternoons. Gusty winds on Tuesday could
create concern with the lower RH and drier vegetation. Temperatures
are just below normal Monday before rebounding ahead of the front on
Tuesday.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
1) A relatively weak and dry cold front may pass through the area by
midweek.

2) Temperatures continue to be cooler and more seasonably normal.

As of 130 PM EDT Saturday: The extended portion remains similar to
the short term, quiet. Tuesday night, guidance has a weak cold front
reaching the area and bringing even cooler and drier air from the
north. Synoptically, the upper low over the Great Lakes slowly moves
eastward, keeping gusty winds around through at least Wednesday
night, when the tight pressure gradient finally moves out. Guidance
does show minimal QPF response with the front, but confidence is
very low as to whether this will actually result in rainfall
anywhere in the CWA. Hence, PoPs for Tuesday night will remain
unmentionable at this time. Looking further into the extended, high
pressure systems continue to dominate the southeast and keep rain
chances a stray. Guidance far out at the end of the forecast show
another area of low pressure forming with yet another cold front,
but tis the season. Whether or not this brings any measurable
rainfall is to be determined. As for temperatures, expect temps to
be normal for October and near freezing overnight temps possible
across the mountains by midweek.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Stratocu at FL030-040 are present over the
mountains and NE Georgia at issuance time but should lift slightly
thru peak heating this afternoon. Expecting VFR to prevail at
all TAF sites including KAVL and KAND this aftn/evening. S to
SW breezes with occasional gusts of 15-20 kt here and there this
afternoon. Increasing pressure gradient will maintain some wind
tonight. FEW low VFR cu may develop but main cloud cover will
be cirrus tonight, becoming SCT-BKN by daybreak Sun, from west
to east. Likely too windy for fog except perhaps in the Little
TN Valley of SW NC. Convection moving thru TN/MS/AL this evening
should weaken to just remnant -SHRA which reach KAVL and perhaps
KAND/KGMU/KGSP 13-15z. Cigs probably low VFR at that time, but
restrictions look likely to develop by late morning, when precip
chances increase. All sites except KCLT get PROB30 before 18z,
with precip prevailing by then at KAVL and KAND. Peak chance for
impactful SHRA is after 18z. Wind gusts to around 30 kt likely
after 18z at KCLT.

Outlook: NW`ly wind shift Sunday evening along with wind gusts of
20-30 kt. Speeds taper off Monday morning, though VFR prevails. Dry
conditions return on Monday. A dry cold front may bring breezy
conditions again on Tuesday lingering into Wednesday.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...JCW
SHORT TERM...CP
LONG TERM...CP
AVIATION...JCW