507
FXUS62 KGSP 160022
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
822 PM EDT Sat Aug 15 2026

.WHAT HAS CHANGED...
The aviation forecast was updated for the 00z TAF issuance.

&&

.KEY MESSAGES...
1. Another Heat Advisory has been issued for most of NE Georgia,
the SC Upstate, and the CLT metro area for Sunday. Hot and humid
weather continues into the first part of next week, with triple
digit heat index values likely over the low terrain each afternoon.
2. There overall severe threat is lower than previously expected
this afternoon but not eliminated. Isolated to scattered diurnal
showers and storms develop each afternoon through the middle
of next week. A couple of strong to severe storms, as well as
isolated nuisance flooding, will be possible each day.

&&

.DISCUSSION...
Key message 1: Another Heat Advisory has been issued for most of NE
Georgia, the SC Upstate, and the CLT metro area for Sunday. Hot
and humid weather continues into the first part of next week, with
triple digit heat index values likely over the low terrain each
afternoon.

The upper anticyclone remains in place to our west through early next
week keeping high heights and thicknesses over the area. This means
the hot temperatures continue through that time period. With elevated
dewpoints continuing through that period as well, heat index values
will exceed 100 outside of the mountains through at least Tuesday.
Another Heat Advisory has been issued for Sunday for the same loca-
tions as this afternoon`s Advisory. Expect another one will be needed
for Monday and possibly Tuesday.

Although the guidance is showing the anticyclone migrating westward
with a steep ridge building over the west coast through the end of
the period, heights over our area don`t substantially fall until
Friday. This keeps the potential for elevated heat index values over
the area until then, although the coverage of triple digit values
will diminish.


Key message 2: There overall severe threat is lower than previously
expected this afternoon but not eliminated. Isolated to scattered
diurnal showers and storms develop each afternoon through the middle
of next week. A couple of strong to severe storms, as well as
isolated nuisance flooding, will be possible each day.

Despite a very unstable air mass, along with steep low level lapse
rates and high DCAPE, remain over our area this afternoon. Shear
remains weak. The frontal boundary to our north won`t move as far
south as expected either. This means that there will a lower
potential for organized storms. However, given the instability and
DCAPE a few severe storms are expected to produce damaging wind
gusts. High PW values and slow moving storms could lead to some
isolated flooding.

Similar conditions are expected into the middle of next week with
isolated to scattered convection, a few severe storms, and possibly
isolated flooding.

For the latter part of the week, a developing shallow trough over
the eastern CONUS could help push a frontal boundary into the area
with better coverage of convection, but details remain uncertain.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: We`ve still got a few clusters of showers
and thunderstorms over the fcst area this evening, with one cell
developing very close to KAVL. I have VCTS for KAVL and KHKY until
roughly 02z, but after that, connective activity should be mostly
done for the evening. Otherwise, expect mostly dry, VFR conditions
thru the period with winds becoming calm at most sites later this
evening and remaining that way thru tomorrow morning. Winds will
eventually pick up from the SW (outside the mtns) tomorrow aftn,
with speeds around 5 kts. Some amount of mtn valley fog is likely
overnight, but it remains unclear if it will reach KAVL. For now,
I have 5SM and SCT003 beginning around 09z. I also have 5SM and
SCT005 at KHKY but my confidence is lower there. The chances for
convection are lower on Sunday with only KAVL carrying a mention
of it at this time with a PROB30 for TSRA. Going forward, if ex-
pected coverage trends higher for our area, more sites will likely
need PROB30s for Sunday aftn/evening.

Outlook: Scattered showers and thunderstorms and their associated
restrictions will be possible each aftn/evening thru early next week.
Low stratus and fog will be possible each morning, especially in the
mtn valleys.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory from noon to 8 PM EDT Sunday for GAZ018-026-028-
     029.
NC...Heat Advisory from noon to 8 PM EDT Sunday for NCZ070>072-082.
SC...Heat Advisory from noon to 8 PM EDT Sunday for SCZ008>014-019-
     104>109.

&&

$$

JPT/RWH