540
FXUS62 KGSP 312314
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
714 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 646 PM EDT Sunday: No major changes to the forecast this
evening.  Mid-level shortwave axis and associated speed max have
translated east of the forecast area per water vapor imagery and
the latest RAP analysis, which also indicate that a closed upper
low has developed just east of the Chesapeake Bay.

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 SUNDAY/...
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 /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: VFR at all terminals despite some lingering
FEW/SCT coverage at around FL030 across the Upstate and Foothills.
Wound up with some convection this afternoon across the NC
mountains, and even a few spots in the western Upstate; however,
the bulk of this activity has waned by this point, and further
redevelopment isn`t looking likely.  Drier air is still expected
to filter in overnight and tomorrow, allowing VFR conditions to
prevail through the remainder of the TAF period.  The exception,
of course, is KAVL, which as usual has a chance of seeing MVFR fog /
low stratus development around dawn Monday.  Generally think Monday
afternoon will have too little convective coverage to warrant even
mention of VCSH at any of the TAF sites.  Expect a steady 5-10kt
northeast wind 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/MPR
SHORT TERM...CP
LONG TERM...CP
AVIATION...MPR