784
FXUS62 KGSP 160003
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
803 PM EDT Tue Jul 15 2025

.SYNOPSIS...
Daily thunderstorm chances continue through the week and into the
weekend. A few storms could produce damaging wind gusts and
localized flash flooding. Hot and humid conditions stick around
through most of the week.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 752 PM EDT Tuesday: No major changes to the forecast
this evening.  Convection is ongoing across the NC Foothills and
parts of the SC Upstate, but is running on fumes at this point
between the loss of strong daytime heating and an increasingly
stabilized environment, and so notable convection shouldn`t persist
for much longer.  Synoptic setup remains unchanged, with a the
periphery of the Bermuda High extending from the west Atlantic
into the Carolinas, and significant PWs of 2-2.2" across much of
the area...so the threat of localized flash flooding remains with
any continuing activity.

Overnight, PoPs continue to decrease...but cannot rule out a pop-
up shower or thunderstorm given the moist environment.  Evening
guidance has become increasingly insistent upon the development
of low stratus and patchy fog after midnight, most focused along
the Blue Ridge Escarpment...and areas that received significant
rainfall this afternoon.  Coverage should be sparse enough that
a DFA shouldn`t be necessary.

For Wednesday, the surface high continues to migrate further west,
bringing more of a S/SW surface wind and enhancing advection
of moisture into the area.  The location of the high could help
to direct activity westward...and indeed the evening runs of the
operational CAMs as well as the RRFS both favor areas west of I-26
for convection overall and support delayed initiation into the
mid/late afternoon.  Temperatures look to remain in the low 90s
(mid 90s further south) with the heat index increasing into the
upper 90s.  A few locations in the southern zones could see HI of
100-103 today, but remains below any Heat Advisory criteria.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 1145 AM EDT Tuesday: The rest of the work week should
be more of the same...typical hot and humid summertime with
mainly diurnal storms both days...as a westward extension of
the Atlantic subtropical ridge keeps us insulated from whatever
happens with the system moving westward along/off the northern Gulf
Coast. The forecast will feature an above-climo precip probability
over the area, particularly the mountains, where differential
heating will provide a focus for convection. The usual isolated
pulse-severe storm threats will apply, and heavy rain could also
be a problem. Fcst soundings show deep warm cloud depths and
slow-moving storms, but the precipitable water will not be quite
as high as the past few days, so the flash flood potential looks
marginal for now. Temps will continue to run 3-5 degrees above
normal, but the apparent temps over the Piedmont should stay below
Advisory criteria Thursday and Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 1225 PM EDT Tuesday: The latest model blend suggests the big
story this weekend and into early next week will be the heat, as
part of the Atlantic subtropical ridge breaks off and moves slowly
west across the Deep South. In spite of nothing to suppress the
deep convection, temps will remain on the order of five degrees
above normal, while tropical moisture remains in place, keeping
the dewpoints in the lower 70s. This combination is forecast to
push the apparent temps up into the Advisory range each day from
Saturday onward across the lower Piedmont and the Charlotte metro
area/western Piedmont, even with mixing down the dewpoint from the
NBM by a couple of degrees. Note that none of this is out of the
ordinary for July. Confidence is marginal at this point anyway,
because there is much on the mesoscale that could derail this
potential, such as the weak upper wave moving past to our north
on Saturday and then a more active convective regime Sunday into
Tuesday as the upper high to our south oozes farther west and
flattens more, possibly bringing the MCS track farther south to
where it would affect the western Carolinas more directly. It`s
not until Monday/Tuesday when we keep precip chances going round
the clock, though, because of a better signal for something going
on aloft to sustain the convection overnight. Through the period,
pulse severe storms and isolated flash flooding will be possible
each day, which is also more or less typical for July.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Midsummer pattern continues with ongoing
convection across the terminal forecast area expected to wind
down in the next 1-2 hours.  In its wake, lingering moisture will
result in widespread MVFR ceilings overnight, pockmarked with areas
of IFR that appear most likely to develop across the NC Foothills
(which makes KHKY the most likely to see this materialize).  After
daybreak, restrictions will gradually scatter out through morning
and we`ll jump right back into another summertime day...with PROB30s
for afternoon/evening convection again Wednesday.  Coverage appears
lower than today, and timing may be delayed compared to the typical
~18-20z onset.

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...None.
SC...None.

&&

$$

SYNOPSIS...CP
NEAR TERM...CP/MPR
SHORT TERM...PM
LONG TERM...PM
AVIATION...MPR