499
FXUS62 KGSP 111738
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
138 PM EDT Tue Aug 11 2026

.WHAT HAS CHANGED...
Increasing chances for severe storms over northern portions of the
area this evening.

Updated the aviation discussion for the 18Z TAFs.

&&

.KEY MESSAGES...
1. Severe thunderstorms are possible across northern portions of
the area this evening. Additional rounds of storms may push into
the area overnight through Wednesday, but confidence is low at
this time.
2. Heat builds by late week into the weekend with continued daily
chances for mainly afternoon/evening thunderstorms.

&&

.DISCUSSION...
Key message 1: Severe thunderstorms are possible across northern
portions of the area this evening. Additional rounds of storms may
push into the area overnight through Wednesday, but confidence is
low at this time.

Broad upper ridging extends from the Gulf States through the
Southern Plains and into the Four Corners region. Deep-layer
northwest flow remains entrenched on the northern flank of the ridge
from the Northern Plains across the Midwest and through the Ohio
Valley and into the Southern Appalachians. This synoptic pattern is
synonymous with late summer "ridge rider" patterns where complexes
of storms develop across the Midwest and drop into the Appalachians.
This exact scenario is already ongoing with two notable MCSs with
the lead complex of storms dropping southeast across portions of
eastern Kentucky into southern West Virginia and western Virginia.
Farther upstream, an intense convective line is dropping southeast
across Indiana into western Ohio. A fairly quiet afternoon is
expected outside of a the potential for a few isolate to widely
scattered pulse type storms. Attention quickly shifts to the lead
complex of storms as it pushes towards the western Carolinas this
afternoon. Storms will likely track along a notable instability
gradient and will make a run towards at least the northern portion
of the forecast area along and north of I-40. Moderate instability
and plenty of DCAPE will support the potential for damaging winds
with any linear segments that survive into the area. Southern extent
of any severe threat remains uncertain, but cannot be ruled out as
far south as the I-85 corridor or even the entire area should a more
robust line of storms be realized. The expanded slight risk down to
the NC/SC state line and marginal for the remainder of the area is
well placed for now.

Forecast confidence wanes by the overnight into early Wednesday
morning as the second complex of storms drops out of the Midwest and
towards the area. Guidance is split as to how far south any storms
survive during the overnight instability minimum and where exactly
they track. The lead storms this evening will likely lay out a cold
pool with the instability gradient shifting farther west in
response. This could keep additional rounds of storms just to our
west, but that`s far from certain with some members of guidance
bringing more convection into the area during the early morning
hours. Any severe threat should be isolated with any overnight
storms, but an isolated flash flooding threat cannot be ruled out
should storms train down the remnant outflow boundary from earlier
activity. Of course the potential for any storms Wednesday afternoon
will be highly dependent on how things evolve overnight.


Key message 2: Heat builds by late week into the weekend with
continued daily chances for mainly afternoon/evening thunderstorms.

By Thursday into Friday, a prominent ridge is forecast to build
across the Deep South with the western Carolinas and northeast
Georgia situated on the northeast flank of the ridge and on the
southern periphery of the deeper northwest flow regime. The ridge
further strengthens through the weekend as it expands into the
Southern Plains. The result will be the potential for a hotter
stretch of weather with afternoon highs creeping into the low to
upper 90s across much of the area. A humid airmass will also remain
in place and will support increasing heat indices with low 100s to
around 105 possible. It`s not out of the question that a day or two
of heat advisories may be needed, but confidence is low to moderate
at this time owing to uncertainty with how much dewpoints mix out
and any degree of convection and debris clouds. Given the persistent
northwest flow, a continued threat for complexes of storms to drop
into the area will persist, especially Thursday and Friday, along
with the potential for more typical diurnally driven
afternoon/evening storms. Given the hot/humid airmass, any storms
that do develop could become severe with a threat for damaging
winds.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Forecast confidence through this afternoon
and evening is lower than usual as multiple complexes of
thunderstorms are evolving to our northwest and may make a run at
the area. Should these storms make it, typical convective
restrictions can be expected, generally between ~21-02z. Regardless
at least a couple isolated storms cannot be ruled out ahead of any
line of storms approaching from the northwest. The overnight should
be fairly quiet and mountain valley fog cannot be discounted, but
confidence is low owing to what could be copious amounts of
lingering cloud cover from decaying storms. Winds will generally be
light and out of the northwest.

Outlook: A few showers or thunderstorms will be possible each
afternoon with flight restrictions possible for low stratus and fog
each morning in the mountain valleys and locations that received
rain the day before.

&&

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

&&

$$

TW