565
FXUS62 KGSP 092328
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
728 PM EDT Mon Jun 9 2025

.SYNOPSIS...
Scattered showers and thunderstorms crosses our area from
Georgia tonight then moves out of our area early Tuesday. Weak and
mostly dry high pressure controls our weather Tuesday and Wednesday.
A Bermuda high creates a moist southerly flow late this week and
into next week with scattered to numerous showers and storms
affecting our region.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 611 PM: Thus far, convection has remained...unimpressive.
Buoyancy has continued to impose a limit on convective potential,
with some isolated cells developing in the western half of the
forecast area, but generally too little forcing for initiation,
and too little CAPE for strong updrafts.  The best chances will
continue to be around the edges of the forecast area, where the
buoyance will approach 1500-2000 J/kg over the next efw hours.
The deeper convection will persist through the evening as a weak
vort lobe approaches the area, so maybe that will spice things up.
Convection upstream over northeast Georgia could, as it arrives
in the southwest Upstate, produce some interesting activity...but
will encounter increasingly CAPE-deficient air as it pushes across
the SC zones.

By late evening, remnant convection dissipates over the mtns and
any lingering storms should move east of the fcst area as the wave
moves overhead. Meanwhile, a weak cold front associated with low
pressure lifting northeastward from the Great Lakes to Ontario will
get pushed over the mtns and will probably stall thru morning. Low
temps will be seasonally mild. Tuesday is a bit uncertain as along
as a boundary remains laid out SW-to-NE across the mtns, which the
GFS shows. If the boundary remains in place, the Marginal Risk on
the Day 2 Outlook looks like a good call. The 15Z RAP develops an
environment with muCAPE around 2500 J/kg to the S and E of I-85
in the afternoon with maybe 25 kt of effective bulk shear, which
is enough to get a few strong to severe storm clusters in that
area. The CAMs depict a similar idea. Keep that idea simmering on
a back burner. Over the mtns and foothills, high pressure would
be building in behind the front, so storm chances would be much
less. The boundary and increased clouds will keep temps down a
few degrees below today.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 1245 PM EDT Monday: Upper trough in place over the
Appalachians with exiting front at the start of the short term will
leave dry conditions in place for Wednesday, but with downsloping
and subsidence in the NW flow aloft, temperatures will bump up a
couple of degrees from Tuesday but still rather seasonal as the
front remains well to the south. Meanwhile, a cutoff midlevel low
will be meandering around the Southern Plains, and as it lifts
toward the MO Valley on Thursday, the front will be pulled back
north with it. Southerly return flow around the western periphery of
the Bermuda high will contribute to the increasingly moist airmass,
with temperatures rising slightly higher still on Thursday and a
return of afternoon convection.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 115 PM EDT Monday: Upper ridge over the surface Bermuda high
will slowly retrograde west toward the Southeast coast as we
approach the weekend, but operational guidance handles the Plains
mid-level cutoff differently. Ensemble guidance all points to above-
normal temperatures and increased upper support for enhanced diurnal
coverage more than typical summertime convection, especially in the
mountains closer to the shortwaves that will be lifting over the
ridge. However, no real deep-layer shear to speak of and poor lapse
rates due to the mid-level ridging may preclude much in the way of
severe convection despite additional coverage. Will have to evaluate
daily threats for isolated wet microbursts as well as building hydro
potential late in the period.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: A cluster of strong to severe convection
is underway across the SC Upstate zones this evening, with
less-pronounced activity across the NC mountains nonetheless
producing flight restrictions at KAVL.  The cluster is expected to
pivot northeastward over the next 1-2 hours, with short TEMPOs in
place for the Upstate terminals, and only KCLT expecting TS/SHRA to
continue past 02z.  Once the activity shifts east...expect gradually
descending ceilings overnight, with MVFR to IFR cigs forecast along
and south of I-85 through daybreak.  Farther north, generally drier
surface conditions are indicative of a better trend overnight...with
at worst, MVFR cigs expected for KAVL and KHKY leading up to dawn.
Guidance isn`t super-consistent with this feature, but especially
given the intense rainfall currently being received in parts of
the Upstate, confidence is high enough to include solid IFR at
CLT, GSP, GMU, and AND.  VFR conditions will return on Tuesday
as ceilings scatter out.  An afternoon cu field should develop
again, but with abnormally low bases in the 030-040 range as
moist SW flow continues and sfc dewpoint depressions remain small.
A raggedy line of convection is depicted in most guidance exiting
the NC mountains and sliding SE across the terminal forecast area
through Tuesday afternoon...but coverage appears low enough that
a PROB30 for TSRA has only been included at CLT for the time being.

Outlook: Mostly VFR Wednesday. Mainly diurnal thunderstorms
return Thursday and will persist each afternoon/evening into the
weekend. There will be potential for late night and early morning
fog and low stratus restrictions each day.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...MPR/PM
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...MPR