172
FXUS62 KGSP 121039
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
639 AM EDT Fri Jun 12 2026

.WHAT HAS CHANGED...
Updated discussion for 12z TAFs.

&&

.KEY MESSAGES...
1. Mainly diurnal convection is forecast through the weekend,
with isolated severe storms possible.
2. Hot and humid conditions continue through the weekend.

&&

.DISCUSSION...
Key message 1: Mainly diurnal convection is forecast through the
weekend, with isolated severe storms possible.

A series of shortwave troughs will track thru the Upper Midwest
and Great Lakes, gradually breaking down upper ridging over the
Appalachians and Ohio Valley. The resulting deep-layer westerly
flow will keep elevated low-level thicknesses and above-normal
temps across the area thru the weekend. Muggy conditions and strong
heating today will allow for fairly strong instability this aftn,
with up to 2500 J/kg of sbCAPE. Deep-layer shear will remain weak,
but may be enough to support a few strong to severe storms, mainly
in the mtns and NC Piedmont. Damaging wind will be the main threat,
as storms could loosely cluster along outflow boundaries. Convection
may track into the Piedmont this evening, but guidance remains
mixed on how much lingers past sunset. Overall, trends seem to be
down slightly on the latest CAMs on coverage and intensity compared
to yesterday`s runs.

A weak front pushes into the area tonight, and stalls on
Saturday. Then another cold front approaches from the west on
Sunday. This should keep decent diurnal convective chances around
thru the weekend. Sunday may see the highest chances over the next
few days, as a more pronounced shortwave and attendant cold front
crosses the forecast area. A few severe storms, with damaging
winds being the primary threat, can be expected both days.

The medium range guidance generally agrees on a broad longwave
trough setting up across the eastern CONUS Monday thru Wednesday,
but disagree on how far south a frontal zone will push and allow
dry air to spread in from the north. The 00z ECMWF and Canadian
show more drying than the GFS. Either way, temperatures will trend
down to slightly below normal thru midweek, and convection should
remain largely diurnal and pulse mode.


Key message 2: Hot and humid conditions continue through the weekend.

Under the influence of an upper ridge, conditions are expected to
be quite hot through the weekend, with temps close to 10 deg above
normal today and 5-8 deg above normal Saturday and Sunday. With the
axis of the ridge overhead, today is expected to be the hottest
day, with highs in the mid 90s across the Piedmont, and lower
90s in the mountain valleys. Dewpts may mix out into the upper
60s this aftn, but max heat indices of 98-102 across most of the
lower elevations. A Heat Advisory remains in effect for Charlotte
and areas south and east, where heat indices will approach 105.

The ridge will begin to flatten with a series of shortwaves tracking
thru the Ohio Valley to the Mid-Atlantic over the weekend. Saturday
is expected to be a little "cooler," but still above normal, with
some potential for near-Heat Advisory criteria being met across the
Lakelands, especially Saturday afternoon. Temps may warm slightly
again Sunday in advance of approaching frontal zone, with again
some potential for near-Heat Advisory criteria. Temperatures begin
a cooling trend at the beginning of the new work week.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Other than some fog around KAVL until about
13z, VFR conditions expected at the TAF sites today. Winds will pick
up out of the SW, generally 5-10 kt, with a few low-end gusts to
around 15-16 kt possible at the Upstate sites this aftn. Isolated
to scattered TSRA expected to develop across the mountains late
aftn/early evening, with some tracking east/southeast into the NC
Piedmont thru the evening. Still expected highest coverage over
NC sites. So will continue with PROB30 for some TS at the NC TAF
sites (guidance continues to trend later with convection this
evening). Convection in the Upstate looks very isolated, so only
VCSH at KGSP and KGMU for early evening. Winds may be variable
around convection this evening, then favoring a NW direction mid
to late evening into tonight, as a weak cold front crosses the
area. With light moist N flow up the valley, could see fog and/or
low stratus at KAVL late tonight. Confidence on any restrictions
elsewhere is low at this time.

Outlook: Diurnal convection and associated restrictions are expected
into early next week. Valley fog and low stratus is possible each
morning, primarily in the mountain valleys.

&&

.CLIMATE...
RECORDS FOR 06-12

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      91 2016     61 1903     69 1981     40 1988
                1894                    1964        1972
   KCLT      98 1956     64 1913     74 1998     45 1972
                1926                    1986
                1902                    1943
   KGSP      99 1914     61 1913     74 1981     47 1972
                                        1920

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
     for NCZ071-072-082.
SC...None.

&&

$$

ARK