178
FXUS62 KGSP 061030
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
630 AM EDT Sun Sep 6 2026

.WHAT HAS CHANGED...
WPC introduced a Slight Risk for Excessive Rainfall for today into
tonight.

SPC now has the entire GSP forecast area highlighted in a severe
risk for this afternoon and evening.

&&

.KEY MESSAGES...
1. Another round of severe weather is expected this afternoon and
evening. Showers and possibly thunderstorms will linger through
much of tonight leading to a low-end flood threat. Make sure you
have multiple ways to receive warnings, especially if you have
outdoor plans.
2. Less hot and humid today with even cooler and less humid
conditions expected for the rest of the week. If you have outdoor
plans today make sure to stay hydrated and take frequent breaks
in the shade or in air conditioning.
3. Rain should linger into Monday before drier conditions return
Monday night, lingering through mid-week. A cold front will bring
rain chances back towards the end of the week.

&&

.DISCUSSION...
Key message 1: Another round of severe weather is expected this
afternoon and evening. Showers and possibly thunderstorms will
linger through much of tonight leading to a low-end flood threat.
Make sure you have multiple ways to receive warnings, especially if
you have outdoor plans.

The Day 1 Severe Weather Outlook from SPC now has the entire area
highlighted in a severe risk for this afternoon and evening. The
latest 00Z guidance is showing both higher instability and higher
shear compared to the 00Z guidance from yesterday. With 00Z CAMs now
depicting 20-30 kts of deep layer shear and 2,000-3,000+ J/kg of
SBCAPE, the severe threat should be similar to yesterday, if not
slightly more organized. Damaging wind gusts and large hail up to 1
inch in diameter are the main hazards with any severe storms that
develop. Timing for severe storms looks to be roughly from 2 PM to
10 PM but could linger later into the evening. Like yesterday,
confidence on exact timing remains low.

CAMs have been fairly consistent showing convection lingering into
the overnight hours. With wind shear expected to steadily decrease
this evening into the overnight, storms will have less movement to
them leading to a low end flood threat. Additionally, any areas that
received heavy rainfall from afternoon and evening convection will
be more susceptible to flooding. As a result, WPC has expanded the
Slight Risk for excessive rainfall into a good chunk of the GSP
forecast area today into tonight. This expansion seems reasonable
give 00Z CAMs are showing the potential for some locations to see
2.5-4.5+ inches of rainfall through 12Z Monday across the heart of
the GSP forecast area (roughly from the escarpment up to just west
of the I-77 corridor). Localized flash flooding cannot be entirely
ruled out, especially for any locations that see multiple rounds of
heavy rainfall.


Key message 2: Less hot and humid today with even cooler and less
humid conditions expected for the rest of the week. If you have
outdoor plans today make sure to stay hydrated and take frequent
breaks in the shade or in air conditioning.

Heat Advisory criteria is not expected east of the mountains today
thanks to cooler temperatures (compared to yesterday) behind a cold
front. But it will still be another hot and humid day, especially
across the Upper Savannah River Valley. These areas may flirt with
Heat Advisory criteria briefly this afternoon but with the LREF only
showing a 20% to 30% chance of reaching advisory criteria today,
this is too low to justify an advisory. Furthermore, afternoon
storms will likely limit the duration of heat advisory criteria like
yesterday.

Relief from the heat and humidity finally arrives Monday with high
temperatures expected to end up near or just below normal.
Unfortunately, below normal highs will not be here to stay as
another upper anticyclone builds over the southern and eastern
United States Tuesday into Wednesday. This will allow above normal
highs to return starting Tuesday. Luckily it will not be as hot and
humid this week as it was last week. The anticyclone gradually
breaks down Wednesday night into early Thursday as an upper trough
digs across the north central United States. This trough will push
across the East Coast Friday into Saturday, dragging a cold front
through the GSP forecast area late Thursday night into Friday. High
temperatures should peak on Thursday ahead of the front before
slightly cooler highs return behind the front Friday into Saturday.


Key message 3: Rain should linger into Monday before drier conditions
return Monday night, lingering through mid-week. A cold front will
bring rain chances back towards the end of the week.

Upper trough remains over the region through Monday keep showers
around. The trough then gets nudged off the East Coast as the
aforementioned upper anticylcone builds eastward across the southern
and eastern United States. This will allow drier condition to return
starting Monday night, lingering through at least Wednesday night.
Diurnal mountain convection looks to return Thursday with convective
chances returning for all areas Friday into Saturday as a cold front
impacts the region.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: Dry and VFR through early afternoon outside
of LIFR fog and/or low stratus across the mountain valleys. KAVL and
KHKY have yet to see any fog/stratus develop and the window is
closing quickly. Another round of TSRA and associated restrictions
will impact the terminals this afternoon and evening so have
maintained TEMPOs this update. Also maintained PROB30s for SHRA and
associated restrictions towards the end of the TAF period as another
round of showers will develop and stick around most of the night per
06Z guidance. Could have some embedded thunder at times but
confidence remains too low to mention. Winds will be N/NW at KAVL
through early afternoon before gradually turning SE/ESE late this
afternoon into tonight. Winds east of the mountains will gradually
turn more N`ly through daybreak, toggling NE the rest of the morning
hours. IFR to MVFR restrictions should develop this evening into
tonight but per usual once SHRA starts cigs may improve somewhat.
Confidence on timing for TEMPOs and PROB30s remains low as guidance
is not in good agreement regarding timing or coverage of TSRA/SHRA.

Outlook: Restrictions, and possibly SHRA, will linger into Monday.
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.

&&

$$

AR