257
FXUS62 KGSP 062322
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
722 PM EDT Sun Sep 6 2026

.WHAT HAS CHANGED...
Severe Thunderstorm Watch in effect for Upstate SC and some
adjoining counties of GA and NC until 9 PM EDT.

&&

.KEY MESSAGES...
1. Scattered showers with heavy downpours may redevelop overnight
and could cause isolated flash flooding, especially over the
mountains. Make sure you have multiple ways to receive warnings,
especially if you have outdoor plans.
2. Rain chances linger Monday before drier conditions return
Monday night, persisting through mid-week. A cold front will
bring rain chances back towards the end of the week.

&&

.DISCUSSION...
Key message 1: Scattered showers with heavy downpours may redevelop
overnight and could cause isolated flash flooding, especially over
the mountains. Make sure you have multiple ways to receive warnings,
especially if you have outdoor plans.

Instability will wane nocturnally this evening, though lapse rates
remain favorable for some degree of elevated convection. As the
front sags farther south and high pressure builds from the Great
Lakes into the mid-Atlantic, low-level flow turns more easterly;
overall slow storm motion will continue, but flow aloft remains
westerly and this suggests remaining convection may "anchor" along
east-facing terrain. PWATs will trend downward slowly from north to
south following the advance of the high pressure, though not fast
enough to preclude a threat of isolated flash flooding, particularly
due to the anchoring or where the overnight precip amounts to a
second round of heavy rain, following storms this afternoon. WPC
also features a Slight Risk for an area east of the Blue Ridge
Escarpment and nearest the overnight position of the front as a
result.


Key message 2: Rain chances linger Monday before drier conditions
return Monday night, persisting through mid-week. A cold front will
bring rain chances back towards the end of the week.

Easterly low-level flow continues Monday as the front settles to our
south and we come under the influence of a somewhat wedge-like
surface high nosing south into the region. Areas of fog and low
stratus may linger well into the morning though clouds are expected
to scatter over much of the Piedmont for the afternoon. A few
showers may linger though with lower PWATs and far less instability,
the threat of heavy rain is much lower. Temperatures will trend 10-
15 degrees cooler, with maxes in the mid-70s to lower 80s. We remain
fairly humid through this period. PoPs fall to 10% or less for most
of the area Monday night and remain low through Wednesday night.
Temperatures do moderate as heights rise aloft and the sfc high sets
up offshore, nearly back to normal Tuesday and then slightly above
normal Wednesday.

Subtle upper height falls do begin over the Appalachians again
Wednesday night as a mature cyclone moves across central Canada,
pulling the next front into the mid-MS and OH valleys. Slight return
flow develops in advance of that feature, warranting chance PoPs
returning for the mountains on Thursday. Some of the global models,
especially the Canadian GDPS, show the surrounding broad trough
inducing a wave along the stalled front, generally near south
Georgia, with small PoPs also being warranted for the lower Piedmont
on Thursday as a nod to that possibility. 40-60% PoPs expand to the
whole area Friday near the Ohio Valley cold front. The orientation
of the front is not especially conducive to a strongly forced severe
weather event, and destabilization appears limited ahead of it.
Quasi-zonal upper flow persists into next weekend so the front could
stall near the region and maintain unsettled weather. Seasonably
warm and muggy conditions should continue.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Lingering VCSH and SHRA through 06z is
possible at most terminals, 07z at KCLT. After 06z, cig restrictions
across most terminals (not KCLT) with IFR restrictions through mid
morning. Confidence in BR is highest at KAVL so a TEMPO from 10z-14z
for 3/4SM vsby. Stratus should clear out as winds pick up after 14z.
Winds remain NE through the period with gusts of 15-20 kts during
Monday afternoon and tapering by the end of the forecast period.

Outlook: Drier conditions return by Monday night, lingering
through mid-week.  This should allow VFR to return outside of
morning mountain valley fog and low stratus.

&&

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

&&

$$

CP/JCW