365
FXUS62 KGSP 281331
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
931 AM EDT Tue Jul 28 2026

.WHAT HAS CHANGED...
Heat Advisory for today was expanded to Greenwood, Abbeville,
Anderson, and Oconee (non-mountains) counties.

SPC Day 1 tornado threat was expanded and now includes all of
western NC, the northern SC Upstate, and extreme northeast GA.

&&

.KEY MESSAGES...
1. Severe weather is possible this afternoon and evening with the
main hazards being damaging winds and large hail, but there will
also be an isolated tornado threat. Make sure you have multiple
ways to receive warnings.
2. Heat and humidity peak today. A Heat Advisory remains in effect
for portions of northeast Georgia until 8 PM and was expanded
to include the western South Carolina Upstate. Stay hydrated,
limit time outdoors and spend as much time in air conditioning as
possible. Never leave people or pets alone in a closed car. Look
before you lock!
3. Less humid, drier, and cooler behind the front Wednesday
through Friday. Even cooler conditions expected over the weekend
with shower and thunderstorm chances returning.

&&

.DISCUSSION...
Key message 1: Severe weather is possible this afternoon and evening
with the main hazards being damaging winds and large hail, but there
will also be an isolated tornado threat. Make sure you have multiple
ways to receive warnings.

We`ll have one more day in the active, northwest-flow "ring of fire"
pattern we have been locked into since late last week. A loosely
organized cluster of storms currently over West Virginia, Kentucky,
and northeastern Tennessee will approach the area late this morning.
Could not rule out a few strong, sub-severe storms but the severe
threat should remain low through the morning hours.

Cloud cover associated with the prefrontal WAA, and/or cirrus debris
from the morning storms, still could inhibit convective development
later in the day, though without a strong cold pool from an MCS it`s
hard to see that completely capping off profiles and thus is
unlikely to preclude a second round of activity nearer the actual
cold front, this afternoon and evening. PoPs are lower in the
afternoon for the southwest quadrant of the CWA, where the morning
activity (and arguably strong downslope flow) has the most potential
to keep things quiet. PoPs are highest in the afternoon along the TN
border for upslope, but also in the eastern Piedmont south of I-85,
where morning activity is likely to have the least effect. However
we will have to monitor convective trends and surface obs throughout
the morning to evaluate the likelihood of the second round taking
shape. By late afternoon or early evening, assuming no inhibition,
2000-3000 J/kg of SBCAPE still may overlap with 40+ kt of
northwesterly 0-6km bulk shear (and strongly curving hodographs). As
the cold front looks to advance SE`wd through the NC Piedmont
accompanied by the shortwave, discrete supercells remain the favored
mode there. Damaging winds and large hail perhaps approaching 2" in
diameter are certainly on the table this afternoon, but 0-1km
helicity exceeds 100 m2/s2 in some areas so there will be an
isolated tornado threat, especially across the Charlotte metro.
Farther west, the frontal orientation is more E-W and a more linear
mode may result, though still with wind/hail risk from embedded
supercell structures. SPC Day 1 Outlook keeps the Slight Risk for
virtually the whole CWA, but with the probabilistic contours more
suggestive of the greatest threat being in our eastern zones.


Key message 2: Heat and humidity peak today. A Heat Advisory remains
in effect for portions of northeast Georgia until 8 PM and was
expanded to include the western South Carolina Upstate. Stay
hydrated, limit time outdoors and spend as much time in air
conditioning as possible. Never leave people or pets alone in a
closed car. Look before you lock!

Increased SW`ly flow will allow highs to end up around 4-8 degrees
above normal this afternoon. Afternoon temperatures will climb into
the lower to mid 90s east of the mountains and the upper 80s to
lower 90s across the typically warmer mountain valleys. Heat indices
east of the mountains will climb into the upper 90s to lower 100s,
with a Heat Advisory criteria in effect through 8 PM for Elbert,
Hart, Franklin, and Stephens counties in NE GA as heat indices from
105 to 108 degrees can be expected. Went ahead and expanded the Heat
Advisory to include Greenwood, Abbeville, Anderson, and Oconee (non-
mountains) counties as these locations will see heat indices from
105-108 degrees as well.


Key message 3: Less humid, drier, and cooler behind the front
Wednesday through Friday. Even cooler conditions expected over
the weekend with shower and thunderstorm chances returning.

Behind the front, temperatures trend back to around climo on
Wednesday, with lower humidity that should keep indices below 100,
and much more stable conditions such that precip chances remain near
zero, except for the TN/NC border area where upsloping could kick
off a shower or two. Appreciably drier air filters in for Thursday
that brings temps slightly lower but heat indices more noticeably
lower. Similar conditions last through Friday. The Upstate and NE
GA, being warmer, actually see RH fall to around 35% Thursday and
Friday, which is exceptionally low for this time of year. A few
spots with enhanced mixing could go even lower.

The Western ridge / Eastern trough pattern lingers into next
weekend, though not as unstable upstream and MCS threats do
not look to recur.  Precip/storms may return Saturday, when a
reinforcing shortwave or upper low rotates into the Eastern trough
and reactivates a warm front over the Southeast; PoPs are now likely
for Sunday. The 00z GFS and ECMWF actually seem to occlude the low
to our west by Sunday, whereas the Canadian GDPS maintains an open
wave, which is more similar to earlier solutions. Thus confidence
and PoPs decrease Monday given the spread in the speed of the low
pressure system. Temperatures do remain mild, likely at least a
little below normal.

&&

.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Winds will be light/VRB at the beginning of
the period but will pick up from the SW 13-16z with diurnal mixing
(exc. NW at KAVL) and gusts of 20 kt are expected to be common
around the area by midday. Conditions are favorable for storms
to form to our north and west during the morning, ahead of an
approaching cold front. A weakening band of SHRA perhaps with an
embedded TS may reach the sites between 15-18z; included VCSH and
an uptick in high altitude cloud cover around that time everywhere
except KAND. With that activity looking unlikely to bring a cold
pool to the area, confidence has increased for TSRA impacts later in
the afternoon to early evening. Went with PROB30s at KAVL and the SC
sites in part due to less confidence on timing, though confidence
has increased on occurrence; if timing confidence increases these
PROB30s could easily be replaced with TEMPOs. At KCLT and KHKY the
timing confidence is better and promotion to TEMPO has already been
done. Environmental factors suggest TSRA will easily produce strong
outflow winds and torrential downpours, pose a threat of localized
damaging winds, and with greater than normal hail potential than
most storms in this area this time of year. VRB gusts to 30 kt and
IFR vsby in the conditional groups. Activity should shift out of
the region this evening as the front passes, and winds shift to
NW at all sites behind the front. A few SHRA could develop near
KAVL overnight due to upslope flow into the mtns. Post-frontal
drying could inhibit fog formation tonight but can`t rule out some
shallow fog after 06z especially where heavy rain falls today.

Outlook: Dry and mostly VFR conditions return Wed thru Fri, with
shower and thunderstorm chances and their associated restrictions
returning over the weekend. Low stratus and/or fog will be possible
each morning, mainly in the mtn valleys.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Heat Advisory until 8 PM EDT this evening for GAZ018-026-028-
     029.
NC...None.
SC...Heat Advisory until 8 PM EDT this evening for SCZ010-011-019-
     104.

&&

$$

AR/JCW