925
FXUS62 KGSP 140437
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1237 AM EDT Wed Aug 14 2024

.SYNOPSIS...
Dry high pressure gradually builds in from the north through
Thursday, pushing a stalled front further south of the area. The
high will drift east off the East Coast Friday, as a cold front
approaches from the west over the weekend. The front will bring a
return of better chances of shower and thunderstorms through Sunday,
then lower chances early next week.

&&

.NEAR TERM /THROUGH TODAY/...
As of 1230 AM EDT Wednesday: Isolated showers over the western SC
Upstate have finally dissipated. Dry conditions are expected to
linger through the rest of this morning. Made some tweaks to PoPs
and thunder chances through the period but no other changes were
needed at this time as the forecast remains on track. Otherwise, dry
low-level air will filter into the area within northeast flow.
Patchy fog will be possible across the mountain valleys and portions
of the foothills generally along the I-40 corridor where moisture
can pool along the escarpment. The extent and magnitude of fog will
be governed by how much dry air filters into the region, thus
confidence on development remains low.

For the rest of today, the NW flow aloft is maintained by the model
guidance, with no mid/upper forcing to speak of. Meanwhile, weak
high pressure will ridge down from the north to give us a decent
day, with more sun across more of the area. Forecast soundings are
generally unfavorable with only shallow instability over the
mountains. All of the CAMs manage to develop shower activity over the
North Carolina mountains, with the best coverage expected along the
central and southern Blue Ridge Escarpment this afternoon. Highs
today will be warmer temps over the NC Foothills and Piedmont and
the eastern SC Upstate. However, slightly cooler temps are expected
across the Little TN Valley and Upper Savannah River Valley.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
As of 200 PM EDT Tuesday: NW flow will be in place across the area
as we move into the short term Wednesday night, with upper troughing
down the East Coast. Upper ridge will be building up the MS Valley,
and surface high pressure in place over the Carolinas and Mid-
Atlantic. Fairly quiet, seasonable temperatures on Thursday with low-
end pops mainly in the mountains due to the light upslope flow. As
the wavetrain moves east for Friday, the ridging will push east and
over the Appalachians and an upper trough will begin to work into
the upper Midwest, dragging a front through the OH Valley.
Temperatures will increase somewhat in response to the building
ridge, and forcing from the approaching wave and attendant surface
front warrants increased pops at least in the mountains by Friday
afternoon, with less confidence further south.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 215 PM EDT Tuesday: The aforementioned front will be on our
doorstep as we move into the extended, pushed by an upper low
working its way from the Upper Midwest across the Great Lakes
through the weekend. The front pushes through during the weekend
while it will be strongly occluded with limited moisture, upper
forcing and and hints of some deep layer shear as it passes to
warrant keeping an eye on to provide some organization to the
convective potential especially for Saturday. The longwave trough
sets up over the Appalachians in the wake of the front but guidance
is in disagreement on whether or not our area is still on the
upslope and unsettled side or on the downslope and drier side. For
now, temps remain just above normal with low-end pops mainly in the
mountains.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: A northeast flow pattern will remain in place
across the region through the TAF period. Showers and a stray storm
continue to fester along the Upper Savannah River Valley in a
corridor of higher instability this evening. A shower may stray
close to KAND over the next hour or so, otherwise no convective
impacts are expected at any other terminals. The main focus
overnight will be the potential for a deck of low stratus and
perhaps patchy fog to develop, especially across the mountain
valleys and I-40 corridor into the Upstate. Confidence in
restrictions is highest at KAVL and KHKY with temporary restrictions
possible at KGMU/KGSP. A few afternoon showers will be possible
across the mountains tomorrow afternoon.

Outlook: Expect mostly diurnal isolated to scattered diurnal
convection through Thursday. Coverage of convection increases Friday
into Saturday as a cold front approaches out of the west. Patchy fog
and low stratus will be possible each night in the mountain valleys
and in any locations that received heavy rainfall the day prior.

&&

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

&&

$$

SYNOPSIS...DEO
NEAR TERM...AR/PM/TW
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...TW