033
FXUS62 KGSP 151812
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
212 PM EDT Wed Jul 15 2026

.WHAT HAS CHANGED...
Slight increases to temperatures Friday into Saturday as well as to
pops Saturday into Sunday.

&&

.KEY MESSAGES...
1. Hot conditions will return to the area tomorrow and continue
into the weekend. Heat index values will return into the 100 to
105 degree range across the Piedmont Thursday through Sunday.
2. A cold front will approach from the north and bring higher
rain chances over the weekend, and slightly cooler temperatures
early next week.

&&

.DISCUSSION...
Key message 1: Hot conditions will return to the area tomorrow and
continue into the weekend. Heat index values will return into the
100 to 105 degree range across the Piedmont Thursday through Sunday.

An upper ridge will remain in place over most of the country over
the next few days, though will gradually begin to break down late in
the the weekend. With the height rises combined with the soupy
airmass, temperatures (and associated RH) will rebound tomorrow to
several degrees above normal, and a 5-8 degree increase over this
afternoon`s forecast highs. NBM dewpoints seem just a tad high given
the deep mixing to 700mb during peak heating, so have blended in
slightly lower dewpoints Thursday afternoon to account for this.
Nevertheless, resulting heat index values rise to near or slightly
above 100 Friday afternoon, and the current forecast is even higher
over the weekend. Heat Advisory conditions may be possible as we
move closer to the weekend, especially in the Lakelands and the
Charlotte Metro area, but confidence remains low given model
handling of the mixed boundary layer. Cannot rule out standard
diurnal convection especially across the SW mountains and TN border,
and with the increasing heat instability may support isolated pulse
severe.


Key message 2: A cold front will approach from the north and bring
higher rain chances over the weekend, and slightly cooler
temperatures early next week.

The moist surface airmass will remain in place, and by late Saturday
a shortwave looks to develop across the Upper Midwest and dive down
toward the central Appalachians. Meanwhile, the ECMWF especially is
developing a weakness in the eastern Gulf, noted on the NHC Tropical
Outlook. The shortwave will push the upper high toward the west,
over the Rockies, allowing the upper trough to dig and bring a
surface front toward the region. Timing of this front vs the Gulf
low may provide additional moisture over the area, or the front may
push through before the Gulf moisture is able to push this far
north, so confidence in the exact sensible weather pattern remains
low. In the current forecast, the upper trough remains over the area
through the end of the period with intermittent shortwaves pushing
through, with enhanced diurnal pops for late in the weekend and then
settling back into a more standard pattern assuming the best
moisture from the Gulf low remains to our south and east.
Temperatures by Sunday into Monday drop back towards seasonal
normals with currently just a slight uptick towards the end of the
period.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
At KCLT and elsewhere: VFR through the period at all but KAVL,
where fog/low stratus is likely to redevelop in the mountain
valleys. Kept trend of IFR vsby starting around 08z. Cannot rule out
an isolate SHRA or TSRA in the vicinity of KAND, but coverage and
confidence not high enough to include in the TAF at this time. Winds
generally lgt/vrb but favoring WSW at TAFs this evening except KAVL
where NW should prevail.

Outlook: Diurnal convective coverage is expected to
increase somewhat Thursday, but should remain confined to the
mountains. Typical mid-July coverage of diurnal convection is
expected to return Friday and continue thru the weekend. Low stratus
and/or fog will be possible each morning, mainly in the mountain
valleys.

&&

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

&&

$$

TDP