613
FXUS62 KGSP 281738
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
138 PM EDT Fri Aug 28 2026

.WHAT HAS CHANGED...
The aviation forecast was updated to reflect the recent 18Z TAF
issuance.

&&

.KEY MESSAGES...
1. Diurnal showers returns on Friday and Saturday, before afternoon
convection becomes more suppressed Sunday and into next week. A
few storms may become strong to severe on Friday afternoon,
producing isolated damaging wind gusts.
2. Hot and humid conditions return for most of next week. Dangerous
heat index values will return to many areas by Wednesday or
Thursday.

&&

.DISCUSSION...
Key message 1: Diurnal showers returns on Friday and Saturday,
before afternoon convection becomes more suppressed Sunday and
into next week.  A few storms may become strong to severe on Friday
afternoon, producing isolated damaging wind gusts.

As of a little after midnight, convection has waned across the
entire region, with a couple of lingering light showers around the
NC Blue Ridge Escarpment but dry conditions elsewhere.  Already
seeing some patchy fog developing across the NC Piedmont, mainly in
locations hit hard by rainfall Thursday evening.  An ill-defined
frontal boundary appears to be draped across eastern Tennessee,
beneath cyclonic upper flow aloft as depicted in recent water
vapor imagery and RAP analyses.

The next couple of days` weather will be driven by the evolution of
these features.  At the surface, we can expect to remain within a
warm sector-like environment through at least Saturday afternoon,
while aloft, a series of weak shortwaves will cross the western
Carolinas, embedded within a deeper trough axis extending from
the Tennessee Valley north into Ontario.  Strong upper flow (for
this time of year) will be present on at least Friday afternoon,
if perhaps less so on Saturday afternoon.

Friday afternoon should feature some 2000+ J/kg sbCAPE
within a weakly-sheared environment of 20-25kts of deep layer
shear...particularly farther east across portions of the Upstate
and the I-77 corridor.  There`ll be enough shear, at any rate,
to support a few semi-organized segments and an isolated damaging
wind threat...as well as sufficient DCAPE for downbursts even from
non- organized cells.  The CAMs generally suggest that convection
will fire over the ridgetops during the early afternoon, then
progress eastward through late evening.  Saturday`s environment
looks less- sheared, but just as unstable...supportive of a couple
strong storms, perhaps even a severe storm or two, but overall
less impressive.  Coverage looks like it`ll become increasingly
sparse on Saturday and Sunday as heights across the area begin to
rise, retreating to the mountains entirely by Monday afternoon as
the supporting trough lifts north.


Key message 2: Hot and humid conditions return for most of next week.
Dangerous heat index values will return to many areas by Wednesday
or Thursday.

By the first part of next week, long-range ensembles are in good
agreement that any lingering weakness in the subtropical ridge
will break down.  In its place, broad anticyclonic upper flow will
develop across the Southeastern United States, setting the stage
for another hot, muggy week.  Guidance features the development of
a Bermuda High-like pattern across the western Atlantic as early
as Tuesday, resulting in the steady advection of better low-level
moisture into the area through the remainder of the week.

The result still looks like a return to above-normal temperatures
and triple digit heat index by Wednesday...with the second half of
the week likely featuring 100-105 degree heat index across much
of the low terrain.  Some uncertainty remains on the details,
but confidence on a hot week is increasing.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Afternoon convection has already developed
across the mountains early this afternoon and is expected to expand
in coverage through the evening as storms move east. This will bring
the potential for TSRA and associated visibility and ceilings
restrictions at all terminals. Thereafter, quiet conditions are
expected to return for much of the overnight. Attention then shifts
to the potential for another round of patchy fog and low stratus,
especially in favored mountain valleys. IFR to LIFR restrictions
will be possible. Any fog should mix out quickly after sunrise with
low stratus lifting and scattering as well bringing a return to VFR
by mid morning. Winds will be light out of the southwest today and
then northeast tomorrow.

Outlook: Widely scattered showers and storms are expected over
through weekend, mostly over the mountains, then entirely over the
mountains by Monday.  Mountain valley fog and low stratus will be
possible each morning.

&&

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

&&

$$

TW