663
FXUS62 KGSP 081843
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
243 PM EDT Tue Sep 8 2026

.WHAT HAS CHANGED...
NBM trending even lower for PoPs on Thursday.

&&

.KEY MESSAGES...
1. Daily shower and thunderstorm chances return Friday through the
weekend in association with a cold front. Above normal temperatures
return by Thursday and generally continue into early next week.

&&

.DISCUSSION...
Key message 1: Daily shower and thunderstorm chances return Friday
through the weekend in association with a cold front. Above normal
temperatures return by Thursday and generally continue into early
next week.

A flattening subtropical ridge will become more assertive across the
Southeast for the latter half of this week, with escalating heat/
humidity expected to result...temps forecast to be more than 5
degrees above climo by Friday. In the interim, while above normal
temps can be expected Wed and Thu afternoons, surface dewpoints are
forecast to mix out sufficiently to preclude significant
destabilization...limiting diurnal convective potential to < 20%
across much of the area both days.

By Friday, heights will begin gradually falling across our region
as a short wave trough progresses across the northeast quadrant
of the country. The leading edge of an associated frontal zone is
forecast to push into the area by Fri afternoon, with increasing SW
low level flow allowing moisture to pool along/near the boundary
to enhance convective chances...warranting likely PoPs across
much of the mountains and solid chances elsewhere. While Friday is
expected to be the hottest day of the week, humidity will be such
that afternoon Heat Index is expected to be solidly below Advisory
criteria, and even H.I. of 100 is forecast to be very localized.

The frontal zone is forecast to stall across or perhaps near the
area over the weekend...certainly close enough to allow plenty of
moisture and at least some instability to linger. While signals in
model guidance are weak...the general pattern of a stalled frontal
zone and very moist conditions will support solid coverage of mainly
diurnal convection amd some degree of an excessive rainfall threat
over the weekend. Otherwise, increased clouds and showers/storms
will allow temperatures to cool to near-normal levels.

By early next week, the global models are in general agreement in
sweeping any deep moisture out to sea while allowing the subtropical
ridge to make another comeback across the Southeast. This will
allow for another warm-up, with temps around 5 degrees above climo
forecast by Monday. Precip chances will diminish, but moisture
and instability are forecast to be sufficient to support diurnal
convective probabilities early next week, mainly over the mountains.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Other than spotty showers across the
mountains west of KAVL later this afternoon, the Terminal
Forecast Area is expected to be free of convection through at
least Wednesday. Lake and/or mountain valley fog/low stratus is
again expected on Wed morning, but a slightly drier air mass may
delay the onset while also limiting the areal extent. For now,
categorical MVFR conditions are limited to KAVL toward daybreak,
with tempo LIFR conditions at KAVL and MVFR fog at KHKY. Otherwise,
VFR conditions are forecast. Generally light E winds this afternoon
will become light/variable or calm this evening.

Outlook: A cold front should bring back daily shower and
thunderstorm chances (and possible restrictions) Friday into the
weekend. The probability of morning fog/low stratus will also
increase, especially in the mountain valleys.

&&

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

&&

$$

JDL