879
FXUS62 KGSP 161026
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
626 AM EDT Thu Jul 16 2026

.WHAT HAS CHANGED...
Only minor changes to the forecast for this update.

&&

.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 /12Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: Mountain valley fog and low stratus
are largely confined to the valleys west through north of KAVL
this morning, and restrictions at KAVL are looking increasingly
unlikely. VFR is therefore forecast at all sites through this
period. Diurnal convection is once again expected to develop
west of the TAF sites this afternoon/evening. Light WSW winds are
expected early and again this evening, with light/variable winds
expected for the remainder of the period. Tonight`s valley fog/low
stratus is again unlikely to directly impact KAVL, although this
will require additional scrutiny in later forecast updates.

Outlook: Coverage of afternoon/evening SHRA/TSRA will increase
Friday but chances appear to be best across the mountains. Even
better coverage of mainly afternoon/evening SHRA/TSRA is expected
this weekend. Low stratus and/or fog will be possible each morning,
mainly in the mountain valleys.

&&

.CLIMATE...
RECORDS FOR 07-16

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      94 1988     69 1930     72 2020     49 1926
                1980        1897
                1932
   KCLT     100 1899     67 1930     76 2020     58 2004
                1887                    1988        2001
   KGSP     101 1887     65 1930     79 1937     57 1888



RECORDS FOR 07-17

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      95 1980     72 1917     77 1887     54 1939
                            1891
   KCLT     100 1986     74 1989     80 1881     62 2004
                1887        1896                    1903
                                                    1886
   KGSP     103 1887     76 1930     76 1934     60 1886

&&

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

&&

$$

JDL