-- Discussion containing changed information from previous version are highlighted. --
078
FXUS62 KGSP 241848
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
248 PM EDT Mon Jun 24 2024

.SYNOPSIS...
High temperatures will peak on Wednesday ahead of a cold front
which will bring the next chance of showers and thunderstorms
to the area.  Hot and humid conditions will persist through the
weekend with a chance of showers and thunderstorms each afternoon.
Another cold front approaches the area late next weekend.

&&

.NEAR TERM /THROUGH TUESDAY/...
A llvl convg zone continues to cross the FA as noted by enhanced Cu
seen on the Vis Sat loops. Dont expect much if any chance of shower
develop as the subs inversion has become well defined and has
lowered to 5 Kft. Soundings show no chance of parcels making it past
this inversion, but if enuf sfc lift remains by max heating there
could a couple pop-up showers, which would be rather brief in
duration. A small-scale sfc high currently located over WV will
migrate southeast and off the Carolina coastline thru the period and
keep winds unfavorable for sfc-layered moisture transport, thus a
morning fog threat will be nil especially with the p/grad remaining
a little tight allowing for weak sfc mixing. On Tue, expect the
upper ridge to remain dominant and large scale subsidence negating a
precip/thunder threat. There will be elCAPE on the order of 1200 Jkg
available, but highly unlikely any of this will be realized with no
sigfnt triggers noted across the region. Lows tonight will remain a
couple degrees abv normal, while highs once again rise above normal
by 5-7 degrees within good insolation.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
-- Changed Discussion --
As of 230 PM Monday...The hottest temperatures of the forecast are
expected for Wednesday ahead of an approaching cold front.
Highs in the mid- to upper 90s east of the mountains are
expected Wednesday afternoon, with highs in the lower 90s in the
mainstem mountain valleys. These highs will still be about 3-5
degrees below long-standing records. Dewpoints Wednesday
afternoon may reach the mid- to upper-60s which would be enough
to push heat indices to 100 in typical locations including
Charlotte and the Upper Savannah River Valley, but nothing
unusual for this time of year. That being said, the profile
suggests deep-layer mixing will likely keep dewpoints below
National Blend guidance, mitigating apparent temperature
concerns. Despite this deep-layer mixing and high cloud bases;
SBCAPE values of 1500-2000 J/kg are expected with steep low-
level lapse rates; therefore, the approaching shortwave energy
and the mountain terrain should provide enough forcing for
scattered shower and thunderstorm development, especially across
the mountains. Bulk shear values of less than 20 kts precludes
any significant concern for severe weather; however, ample dry-
air aloft suggests a strong downburst or two cannot be ruled
out. Overall, given underwhelming moisture content through the
column, we are not expecting notable precip outside of isolated
locations with this activity.

The airmass behind the front for Thursday is actually a bit
more moist through about 500mb, especially in the mountains.
Lapse-rates aren`t as steep through the mid-levels as on Wednesday,
but the LCLs/cloud-bases are expected to be a bit lower as well.
Forecast soundings suggest unimpressive SBCAPE values below 1000
J/kg, but the proximity of lee troughing and terrain enhancement
should be enough for another round of scattered showers and
thunderstorms.  National Blend is a bit more aggressive with PoPs
Thursday afternoon than preferred given the profile and pattern,
but this will be another high PoP/low QPF scenario with little
appreciable rainfall expected.  Expect little moderation behind the
front east of the mountains with highs 2-4 degrees "cooler" than
Wednesday, but still 2-4 degrees above normal.  The influence of
the front will be a bit more discernible in the mountain valleys,
with highs 5-7 degrees cooler than Wednesday, though once again
these highs will still be slightly above normal.
-- End Changed Discussion --

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
-- Changed Discussion --
As of 230 PM Monday...The extended period will feature a resurgence
of the heat ridge over the Lower Mississippi River Valley, keeping
us on the southern fringe of the active westerly flow across the
northern half of the ConUS.  This upper-level pattern suggests
that we should be able to maintain diurnally driven isolated to
scattered shower and thunderstorms Friday and Saturday with the
best coverage in the climatologically favored mountain zones.
Once again, there is not enough forcing or moisture to suggest any
notable relief from ongoing dry conditions.  High temperatures are
expected to remain several degrees above normal through Sunday,
with low-level flow gradually becoming more conducive for moisture
advection from the Atlantic and eastern Gulf.  Therefore, expect
increasingly humid conditions heading into the weekend, as the
next cold front approaches the area later Saturday into Sunday.

The aforementioned moisture flux into the region through Sunday
may put us in a better position for more notable convective
coverage and rainfall along and ahead of the cold front, which is
currently expected to enter the area later Sunday.  While it is
much too early to get our hopes up, the favorable return flow may
allow PWs to approach 2 inches on Sunday with ample instability.
Bulk shear values look anemic at this time, so the primary focus
here is improved coverage and better opportunities for more of
the area to see some much-needed rainfall.
-- End Changed Discussion --

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
At KCLT and elsewhere: VFR flight conds will continue across all
sites thru the period. A sfc high center will migrate from West
Virgina to the Carolina coast which will veer winds outside the mtn
valleys from nw/ly to ne/ly or e/ly. Winds at KAVL will remain nw/ly
this evening and become channeled se/ly aft daybreak Tue. Winds
remain a little elevated overnight as a modest p/grad is maintained,
so dense fog will not be an issue except perhaps across the
sheltered mtn valleys of southwest NC.

Outlook: Widely scattered SHRA/TSRA may return as soon as Wed
aftn/evening, with seasonable summertime weather returning then and
continuing into the weekend.

&&

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

&&

$$

SYNOPSIS...JMP
NEAR TERM...SBK
SHORT TERM...JMP
LONG TERM...JMP
AVIATION...SBK