029
FXUS62 KGSP 081031
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
631 AM EDT Sat Aug 8 2026

.WHAT HAS CHANGED...
Updated the aviation discussion for the 12Z TAFs.

&&

.KEY MESSAGES...
1. Mainly diurnal thunderstorm activity is expected today and
again Sunday, with a few storms posing a threat of isolated flash
flooding and perhaps one or two severe storms producing damaging
wind gusts.
2. Temperatures will climb back above normal on Monday, after
which it will be hot and humid each day through mid-week. Some
Piedmont/Upstate locations could have afternoon heat index between
99-103 beginning Monday.

&&

.DISCUSSION...
Key message 1: Mainly diurnal thunderstorm activity is expected today
and again Sunday, with a few storms posing a threat of isolated
flash flooding and perhaps one or two severe storms producing
damaging wind gusts.

Not much change from previous thinking after a look at the new
model guidance. The weekend should be a transition between the
relatively active pattern of late with a weakness aloft to our
west, and a warmer regime as the Atlantic Subtropical Ridge builds
in from the east by Monday. Overall, the pattern highly favors
diurnal convection today and Sunday with the best coverage over
the mtns and foothills. As noted by the day shift, the SW flow
will tend to keep most of the convection near the higher terrain,
so those areas will get a likely precip prob both days. Meanwhile,
guidance suggests areas south/east of I-85 will have more isolated
convection today, and maybe better coverage Sunday afternoon. Either
way, outflow boundaries could allow for storms to propagate
anywhere. Buoyancy should top out in the 2500-3500 J/kg range with
just enough mid-level dry air to provide enough potential for strong
downdrafts that could produce a few severe wind gusts. Shear of
15-20 kt might also allow for some weak organization. The heavy
rain threat is probably the bigger concern, though a modest one
at that. Precipitable water will remain high and warm cloud depth
will also remain high, so the Marginal Risk of excessive rain
looks reasonable. An isolated flash flood or two can`t be ruled
out. Temperatures should be close to normal both days.


Key message 2: Temperatures will climb back above normal on Monday,
after which it will be hot and humid each day through mid-week. Some
Piedmont/Upstate locations could have afternoon heat index between
99-103 beginning Monday.

The latest guidance continues to show the Atlantic Subtropical
Ridge building back in from the east on Monday, though perhaps
suppressed more to the south than previously shown. As a result,
temperatures have trended down ever so slightly, which helps to keep
the heat index merely in the hot and uncomfortable range instead of
up into the Advisory range. Thus, confidence in the need for any
advisories has gone down. The slightly more westerly flow favors
mountain convection each afternoon, with some moving out over
the western Piedmont late in the day. What is more interesting is
that we might get more into an MCS track by Wednesday afternoon
as we come more under the influence of the trof passing to our
north mid-week. This is not really reflected in the precip probs
yet, though a more widespread chance is shown for Thursday. If
the trend continues, we could be closer to a boundary sagging
southward by the end of the week, which would help keep temps
further in check. Confidence in any of this is relatively low.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Satellite imagery shows clouds over the
mountains steadily obscuring the low stratus and fog that has
developed in the mtn valleys. Expect KAVL to remain variable
between MVFR and LIFR with fog and stratus for the first few
hours. Meanwhile, a patch of MVFR clouds have developed near
KGSP, so we take that into account for a brief TEMPO group
there and KGMU. Elsewhere, VFR. Wind should become light SW by
mid-morning. Won`t rule out a very brief broken MVFR ceiling
anywhere as convective clouds form in mid/late morning, but for
now the chance is too low to mention in the TAF. Thunderstorms are
expected again this afternoon, with the best chances over the mtns
and foothills of NC, thus KAVL gets the TEMPO and KHKY gets the
PROB30 for associated restrictions. The other terminals have too
low of a chance to include the storms at this point. The convection
should die off in the middle part of the evening, after which only
debris clouds remain.

Outlook: Scattered diurnal showers and thunderstorms, with
associated flight restrictions are expected each day through early
next week. Patchy fog and low stratus will be possible each morning,
especially in the mtn valleys and anywhere that received significant
rainfall the previous day/evening.

&&

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

&&

$$

PM