435
FXUS62 KGSP 150001
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
801 PM EDT Sun Jun 14 2026

.WHAT HAS CHANGED...
Updated the aviation discussion for the 00z TAF issuance.

&&

.KEY MESSAGES...
1. Bands of showers and thunderstorms will progress across the
area this afternoon and evening. A few storms embedded in the bands
will pose a risk of damaging wind gusts. Today will be the last hot
and muggy day before a cold front pushes through the area tonight.
2. Drier and slightly below-normal temperatures Monday trough
Wednesday, with moisture and rain chances increasing in the second
half of the week.

&&

.DISCUSSION...
Key message 1: Bands of showers and thunderstorms will progress
across the area this afternoon and evening. A few storms embedded
in the bands will pose a risk of damaging wind gusts. Today will
be the last hot and muggy day before a cold front pushes through
the area tonight.

A weak vort max initiated clusters of showers and storms which
have now pushed through the western half of the CWA as of 2
PM. Extrapolated motion has proven to be a decent predictor of
timing with this activity so far, due to the support of the
vort max. These initial clusters will probably push east of
the eastern CWA border by 5 PM. Pockets of 40-50 mph gusts have
occurred with the stronger cells and some scattered power outages
(not yet confirmed to be due to wind). LCLs appear to be fairly
high out ahead of the current activity, per GOES soundings, and
that may explain why cumulus development has been limited so far,
which suggests coverage and intensity of storms may be kept in
check despite diurnal destabilization, though DCAPE is higher in
that area than what the initial storms were exposed to, so at least
an isolated damaging wind gust is possible. Whether the airmass
recovers to support a second round of storms later remains to
be seen; clear skies remain in the cold pools, but forcing does
increase later this evening ahead of the main prefrontal trough
and cold front. Instability gradient evident on SPC Mesoanalysis
in NW-SE orientation, such that the best instability this afternoon
would be in the Savannah Valley. New convection forming in the mid
Tennessee Valley near those features would appear to track thru N GA
and potentially into the Lakelands, NE GA and the western Upstate,
if the earlier round did not overturn the airmass there. For now
we advertise a 20-40% chance of a second round after sunset in
those areas. A few showers also could redevelop tonight near the
TN border along the front itself.

Heat index is expected to top out near 100 this afternoon in our
southeastern zones and the CLT metro before the arrival of storm
outflows. Temps will trend cooler in the mountains tonight but
Mon morning mins likely will be similar to those the previous
morning elsewhere.


Key message 2: Drier and slightly below-normal temperatures Monday
trough Wednesday, with moisture and rain chances increasing in
the second half of the week.

Temperatures trend cooler Monday, back to around normal in the
Piedmont and slightly below normal in the mountain valleys. Drier
air will however advect in on northwest winds behind the front,
and heat index will be substantially lower, remaining below 90
in most locations. The drier air also should result in suppressed
diurnal convection such that precip chances are less than 10 percent
through evening. Min temps return to near or a little below normal
Monday night. No significant change in that the front still looks to
remain stalled to our south through Wednesday. Tuesday trends still
cooler, below normal for all, and also likely free of precip. There
remains the possibility that the broad shortwave moving thru the
Ohio Valley Tuesday night or Wednesday could initiate upglide
over the stalled front and result in a few showers over the area,
so a few blips of 20% PoP return. Temps also trend back at or above
normal Wednesday with the airmass modifying quickly under June sun,
though humidity remains low.

Deterministic models still depict a somewhat unseasonably strong
sfc low developing near the Great Lakes by Thursday, bringing
another cold front southward thru the lower MS Valley Thu night
or Friday along with another broad trough. They generally also
depict a remnant of the tropical disturbance interacting with
the front as it nears the Gulf Coast, though it becomes absorbed
into the trough more quickly than on earlier depictions, looking
more like a frontal wave as it reaches our area--aside from the
EC which still shows a compact but distinct low riding along the
boundary. Details are murky, and thus confidence low, as to how
far south the front settles before stalling, but it still bears
watching whether this might set us up for a period of heavy rain
and/or severe weather. Gusty winds remain in the forecast Thursday
and Friday. Temperatures remain above normal Thursday but currently
look to trend below normal Fri-Sat if the front manages to ooze
its way south.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: A prefrontal trof is currently passing over
the western Carolinas as a second round of showers and thunderstorms
begins to move into the NC mtns and NE Georgia just ahead of the main
cold front. The SC Upstate sites have seen a fair amount of sunshine
since the first wave of convection moved thru earlier today, and have
had time for some amount of destabilization this afternoon/evening.
Thus, I have PROB30s for -TSRA for KGSP, KGMU, and KAND from roughly
00 to 04z this evening. Coverage is not looking good enough at this
time to warrant TEMPOs. Confidence as to whether KAVL, KHKY, and KCLT
will be unstable enough for a second round of TSRA is not very high.
Thus, I have opted to go with a TEMPO for -SHRA at KAVL and VCSH for
KHKY and KCLT later this evening. I can`t rule out TSRA at these sites,
but it`s looking more unlikely. KAVL may see low VFR or intermittently
MVFR cigs with upslope flow developing behind the front later tonight,
but more than likely, I think they will remain VFR. Otherwise, Monday
should be dry with few to sct high clouds and maybe a few diurnal cu.
Outside the mtns, winds will remain SWLY thru the overnight and then
go N of W around 10z behind the front. They will remain NWLY to WLY
for the remainder of the day. At KAVL, winds should go NWLY later
this evening and remain that way for the rest of the TAF period with
some low-end gusts between 15 and 20 kts Monday morning.

Outlook: Mostly quiet conditions expected thru midweek. Fog and low
stratus will be possible each morning, primarily in the mtn valleys.
Diurnal convection and associated restrictions will likely return
Thursday and Friday.

&&

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

&&

$$

JCW/JPT