967
FXUS62 KGSP 311755
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
155 PM EDT Sun Aug 31 2025

.SYNOPSIS...
High pressure will remain over the East Coast into mid week.. Expect
isolated to scattered afternoon and evening showers and a few storms
for the mountains early in the week.  There will be greater coverage
of the showers and storms into the foothills and Piedmont on
Wednesday and Thursday as a cold front approaches from the
northwest. Temperatures remain below seasonal normals through the
week.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 135 PM EDT Sunday: The latest water vapor imagery indicates
a mid-level speed max digging into the region, with an upper low
beginning to form over the upper Mid-Atlantic within broader long
wave trough centered from New England into the Carolinas. This
favorable setup for upward vertical motion...augmented by sbCAPE
of 500-1000 J/kg is resulting in scattered deep convection
across the southern Appalachians this afternoon. Activity has
been exclusively showers so far...but a rumble or two of thunder
will be possible with a handful of deeper cores as the afternoon
wears on. Convection has been fairly progressive thus far...and
rainfall rates rather tame. Some very isolated heavy rainfall can
be expected this afternoon, but that`s about the extent of the
convective threat.

Otherwise, upper ridge/confluence zone north of developing upper low
will support 1025+ mb surface high pressure settling over the
northeast Conus tonight, which is forecast to result in a
sharpening/deepening of the inverted ridge axis nosing down the
foothills and Piedmont of the Carolinas. As a result, drier low
level air is expected to be forced into the CWA from the northeast
tonight into tomorrow. Any low clouds and shower potential should
therefore become shunted to far southwest NC and northeast GA early
this evening before activity dissipates altogether as instability
depletes by mid-evening or so. This trend will also be seen in
tomorrow`s sensible weather, as cooler conditions and anomalously
low surface dewpoints coincident with the ridge axis will result in
any weak diurnal instability being confined to the Smokies and
vicinity. PoPs of 20-30% are therefore confined to that small area
of the CWA Monday afternoon...with the thunder potential remaining
quite limited due to warm mid-level temps/weak capping. Temps are
expected to be 5-10 degrees below climo through the period.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 120 PM EDT Sunday: A stubborn ridge out west continues to
influence the downstream pattern in the eastern CONUS as a weak
cutoff low pushes east in the Mid Atlantic region. Towards the end
of the short term period, a strong upper low starts to dive
southward from Canada, strengthening the trough over the eastern
portion of the country. Meanwhile, surface high pressure over the NE
lingers into Tuesday, reinforcing the drier and cooler air before
eroding on Wednesday. Guidance doesn`t show too much in terms of
moisture recovery on Wednesday as PWATs remain relatively drier.
However, as the upper low plunges south and disrupts the flow aloft,
the growing trough an abundance of shortwaves traversing over the
CWA throughout the period. Although not anticipating much in terms
of shower or thunderstorm activity, cannot rule out a few stray
showers or rumbles of thunder over the mountains. For this low
confidence in precip chances, will keep a slight chance (15-30%) for
the far western NC mountains on Tuesday with an uptick (30-60%) over
more of the mountain zones Wednesday. Temperatures remain steady and
just below normal.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
As of 125 PM EDT Sunday: Not much changing in the extended as the
upper low over Canada goes full Hulk mode across the Midwest and
Great Lakes region. In response, the ridge out west amplifies and
the persistent trough across the eastern CONUS gets reinforced. As
of now, the long range guidance keeps the tighter pressure gradient
to the north, which could help reduce the winds across the area,
especially at the higher elevations. This could change if the trough
dips further south. Meanwhile, a few embedded shortwaves traverse
across the CWA, increasing rain chances. This will be highly
dependent on how much moisture can return on Thursday. For now,
keeping the higher PoPs in the mountains near slight chance/chance
(30-50%), and slight chance (15-30%) elsewhere. By Friday and into
the beginning of the weekend, a weakening frontal boundary could
cross the area and shunt rain chances afterwards. Overall, the
pattern remains cool, dry and helping to keep the tropical season
quiet. Let`s keep it that way. Temperatures remain near normal
through the end of the period.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
At KCLT and elsewhere: MVFR cigs lingering near KGMU and KGSP
should lift and scatter prior to late afternoon. Otherwise,
convective weather is a little more active than in recent days,
with scattered showers ongoing across the mountains, and even
some isolated activity across the foothills. KAVL stands the best
chance for seeing impacts this afternoon, and a tempo for SHRA w/
MVFR conditions is advertised there this afternoon. A shower is
also possible at KGSP/KGMU/KHKY, but chances are only around 20%
at those sites, and will therefore hold off on any TAF mention at
this time. A sharpening/deepening surface ridge axis will drive
drier low level air into the Terminal Forecast Area tonight into
Monday, and VFR conditions are expected to prevail at all sites
outside of the mountains during that time frame. Restrictions
are likely to develop in the mountains valleys late tonight/early
Monday. As usual, the greatest chances for restrictions will be
in the valleys to the W and N of KAVL, but MVFR visby is also
forecast at KAVL. With the drier air filtering into the region,
Monday afternoon is expected to be much less convectively active
than today. Winds will generally remain NE at 5-10 kts through
the period.

Outlook: At least scattered afternoon/evening convection will
return for much of the area Wed and Thu before diminishing again
late in the week. Nocturnal valley fog and/or low stratus will
also be possible each night and early morning, especially at
mountain terminals.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...JDL
SHORT TERM...CP
LONG TERM...CP
AVIATION...JDL