641
FXUS62 KGSP 021824
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
224 PM EDT Wed Sep 2 2026

.WHAT HAS CHANGED...
A Heat Advisory has been issued for Union County, NC from 11 AM to 8
PM Thursday. Additional counties may be added to the Advisory later
today or tonight.

&&

.KEY MESSAGES...
1. Unseasonably hot and muggy conditions continue through the
week. A Heat Advisory is in effect Thursday for portions of the
North Carolina Piedmont. Relief is forecast arrive early next week.
2. Showers and thunderstorms are forecast over the mountains each
afternoon through the work week, but coverage and intensity should
remain limited. Chances for showers and storms begin to increase
for all areas over the weekend into Monday.

&&

.DISCUSSION...
Key message 1: Unseasonably hot and muggy conditions continue through
the week. A Heat Advisory is in effect Thursday for portions of the
North Carolina Piedmont. Relief is forecast arrive early next week.

The center of a strong upper anticyclone will continue to settle
over the southern Appalachians and vicinity through tonight,
persisting through at least Thu night before weakening/retrograding
in response to northeast Conus height falls late in the week. The
result will be unseasonably hot conditions persisting through
at least Saturday, with max temps expected to range from 7-10
degrees above normal each day. Having said that, deep afternoon
mixing along with gradual/slight drying of the atmospheric column
are anticipated, which is expected to allow surface dewpoints to
lower to the mid/upper 60s during peak heating. Therefore, while
plenty of 100-105 Heat Index values are expected this afternoon
and again Thursday afternoon across the Piedmont and portions of
the foothills, confidence is modest at best that Heat Advisory
criteria will be met in any location. An exception is across Union
County-NC, where probabilistic guidance as well as ongoing temp/
dewpoint trends are lending increased confidence that Advisory
conditions will be met for at least a couple of hours Thu afternoon.
A Heat Advisory has been issued for that county for tomorrow. It`s
possible that additional counties within the Charlotte metro area
could be added this evening based upon how temp/dewpoint trends
evolve over the next few hours (as conditions tomorrow should be
very similar to today.)

The potential for Heat Advisory conditions may increase Fri/Sat
as the atmosphere begins to moisten a bit and mixing becomes
more shallow, but residual heat lingers, with perhaps only a degree
or so expected to be shaved off max temperatures despite height
falls. Even if Heat Advisory criteria are not met late in the week,
impact-based considerations will come into play owing to the
attritional effects of 4+ days of hot weather as well as it being a
holiday weekend. Cooling conditions are finally expected early next
week as the upper trough off the East Coast continues to deepen,
likely introducing a frontal boundary to the forecast area along
with increased convective activity/cloud cover. Near-normal
temperatures are therefore forecast from Monday-Wednesday.


Key message 2: Showers and thunderstorms are forecast over the
mountains each afternoon through the work week, but coverage and
intensity should remain limited. Chances for showers and storms
begin to increase for all areas over the weekend into Monday.

Spotty deep convection has been slower to develop this afternoon in
comparison to yesterday. However, conditions are unstable...even
a little more unstable than Tue afternoon, and satellite imagery
depicts congestus over the ridge tops of the southern mountains,
so spotty deep convection is still expected to develop over the
high terrain this afternoon, but activity will again be limited
to the mountains. Generally more of the is expected Thu and Fri
afternoons, with perhaps a little more coverage possible Friday
as the anticyclone begins to weaken/retrograde and the air mass
moistens up a bit. Nevertheless, activity should remain confined
to mostly the mountains, as forecast profiles across the lower
elevations feature weak capping and/or high LFCs each afternoon
through Friday.

By Saturday afternoon, the leading edge of a frontal boundary
associated with East Coast height falls is forecast to move into the
forecast area, interacting with a quite unstable air mass to produce
scattered diurnal convection across the entire CWA. Increased
targets of opportunity, robust instability, and increasing deep
layer shear along the southern periphery of the westerlies will
yield an uptick in the potential for a few strong-to-severe storms
Sat afternoon.

By Sunday, the leading edge of the boundary is forecast to be
south of the CWA, but moisture and some linger instability on
the cool side of the boundary...combined with a developing ESE
upslope flow should result in showers and some storms lingering
into the early part of the week. By Tue/Wed, sufficient drying is
forecast outside the mountains to bring an end to the showers and
storms there, but isolated diurnal activity will possible across
the mountains both afternoons/evening.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
At KCLT and elsewhere: The weather pattern will remain stagnant
through at least Thursday, and aviation weather will therefore
be very similar to the past 24 hours. Spotty convection this
afternoon is again expected to remain confined to the mountains,
with chances being insufficient to mention convection at any site
this afternoon/evening. Fog/low stratus will again develop in the
mountain valleys after midnight, but will again be most likely to
the west and north of KAVL. MVFR conditions are currently forecast
at KAVL between 09-13Z, but IFR or worse conditions cannot be
ruled out. Otherwise, VFR is forecast to continue. Winds will
remain light/variable...perhaps favoring a light S/SE component
this afternoon into the evening.

Outlook: Isolated to scattered mountain convection expected through
Friday, then expanding to all areas for the weekend. Fog and low
stratus will be possible each morning, primarily in the mountain
valleys.

&&

.CLIMATE...
RECORDS FOR 09-02

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      91 2020     65 1928     70 2020     45 1967
                2011
   KCLT      99 1932     67 1928     74 1993     53 1967
                                        1947
                                        1941
   KGSP     100 1912     65 1928     73 2020     50 1887
                                        1947
                                        1932



RECORDS FOR 09-03

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      92 2020     66 1994     70 1993     44 1967
                            1920
   KCLT      98 1925     69 1994     75 1993     52 1967
                                        1990
                                        1941
   KGSP      97 1962     65 1994     74 2015     52 1967
                1944
                1925



RECORDS FOR 09-04

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      95 1954     67 1913     70 1925     45 1952
   KCLT     100 1925     70 1974     75 1925     54 1952
                                                    1886
   KGSP     100 1954     67 1920     76 1925     52 1892
                1925                    1905

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Heat Advisory from 11 AM to 8 PM EDT Thursday for NCZ082.
SC...None.

&&

$$

JDL