615
FXUS62 KGSP 181755
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
155 PM EDT Fri Jul 18 2025

.SYNOPSIS...
Daily mainly afternoon and evening shower and thunderstorm chances
continue through the start of next week. A few storms could produce
damaging wind gusts and localized flash flooding. A weak cold front
slowly crosses our area from the north Monday night and Tuesday.
This front will temporarily bring temperatures closer to normal into
mid week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 140 PM Friday: A 597 dam anticyclone will drift westward over
FL tonight, keeping the jet stream to our north. A quasi-stationary
front draped across the Ohio Valley to the Mid-Atlantic Coast
is expect to nudge slightly further north of the forecast area
thru Saturday. Diurnal convection is kicking off like usual
across the high terrain, and should remain most numerous over
the NC mountains. A west-southwesterly steering flow will try to
carry some activity east across the northern NC Foothills and NW
Piedmont. Areas along and north of I-40 have the highest DCAPE
and MLCAPE in the forecast area per latest SPC mesoanalysis,
and marginal effective shear around 25 kt could help storms
organize around outflows into multicell clusters. So there may be
a few severe storms producing damaging wind gusts. Locally heavy
rainfall will also be possible where storms manage to anchor or
train. Activity should be much more isolated in nature across
the lower Piedmont along and south of I-85. Temps are on track,
but dewpts are mixing out a little more than expected, with even
some gustiness seen in the early aftn METARs. The Mesonet obs
notwithstanding, it looks like the Heat Advisory criteria will
struggle to be met this aftn.

Tonight, convection should wane, with a few stray showers
possible into the overnight. Mountain valley fog will be likely,
but otherwise, skies become mostly clear. Lows will be a category
or so above normal.

Saturday looks to be almost a carbon copy of today, with only
subtle changes in the air mass and overall flow. Given the mixing
occurring today, have blended in the NBM 10th percentile dewpts to
lower them a few deg during peak heating. This keeps heat indices
mostly below 105 degrees. There may be a need for another Heat
Advisory for Mecklenburg, Cabarrus, and Union; but confidence is
too low and will hold off until the current advisory expires and
reassess. Greenwood, Abbeville, and Elbert are also close to 105
heat index, so may need one if confidence increases. Otherwise,
similar trend of timing and coverage of diurnal convection. Also,
similar environment for a few strong pulse storms and isolated flash
flood threat (again mainly NC mountains and I-40 corridor east).

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 1205 PM EDT Friday: Mid level ridging will slide slowly
westward through the short range period, but will act to keep hot
and humid conditions in place regardless. Highs both Sunday and
Monday will be 3-4 degrees above normal with high dewpoints leading
to heat indices near advisory criteria in our southern and eastern
areas.

Showers and thunderstorms will develop each afternoon and evening.
Pops will be pretty high in the mountains with lower pops in the
Piedmont. Overall, pretty typical conditions for late July.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
As of 1210 PM EDT Friday: Mid level ridging briefly pushing west
will allow a weak cold front to impact the area Tuesday with
slightly less hot temperatures, i.e. near normal. The ridge will
rebuild through the rest of the week, so highs will climb back to
several degrees above normal after Tuesday.

Pops will be the highest with the front on Tuesday and then slowly
get lower through the week.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Another round of afternoon/evening
thunderstorms is expected, especially across the mountains and
adjacent foothills where a TEMPO will be carried for KAVL and KHKY.
Elsewhere, coverage is expected to be lower with just a PROB30s
being carried. More mountain valley fog is expected again tonight
with some impacts across the foothills also possible. Otherwise, the
rest of the area should remain VFR. Saturday looks very similar to
today, with convection firing toward the end of the 18z TAF period.
Have a PROB30 for KCLT for 21z Sat to 00z Sun.

Outlook: Thunderstorm chances each afternoon/evening. Low stratus
or fog are possible each morning in mountain/river valleys.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Heat Advisory until 7 PM EDT this evening for NCZ071-072-082.
SC...None.

&&

$$

SYNOPSIS...DEO
NEAR TERM...ARK
SHORT TERM...SCW
LONG TERM...SCW
AVIATION...ARK