769
FXUS62 KGSP 050107
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
907 PM EDT Fri Jul 4 2025

.SYNOPSIS...
Dry high pressure will linger atop the region into Saturday with an
influx of Atlantic tropical moisture expected on Sunday.  Hot and
more humid conditions will return on Monday and linger through
midweek featuring daily afternoon and evening shower and
thunderstorm chances.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 9 PM Independence Day: Fortunately, Mother Nature has
decide to sit this one out, with no thunderstorms at sunset and
limited instability to provide the fuel for it. Just a few
isolated showers have developed in the Upstate early this
evening - one currently near the NW Greenville-Pickens County
boder and another in the far southeast corner of Union County.
While an additional rogue shower or two may develop this
evening, coverage will be far too low (closer to 1%) to
explicitly have rain in the forecast. Conditions overall remain
favorable for fireworks displays this evening, with no
significant weather distruptions expected. Nonetheless, we`ll
keep a close eye on radar just in case any sneaky showers try to
steal the spotlight, but at this point, it looks like the only
fireworks tonight will be manmade.

Upper ridge will shift eastward over the eastern third of the
CONUS through Saturday. Sfc high now over the Appalachians and OH
Valley in turn will center offshore. Low level flow should remain
generally northeasterly thru the period.  Weak instability will
develop diurnally this afternoon but subsidence inversion appears
to limit the depth of convection and thus keep precip chances very
low. A few isolated cells may develop over the SW NC mountains
where the inversion is weakest and warrants a 15-20% PoP. Can`t
completely rule out a shower/storm in the Upstate, but any such
activity should be so isolated PoP is being kept below 10% there.

With Tropical Depression Three expected to remain off the SC on
Saturday, direct sensible impacts on our CWA is not expected. Some
hi-res models depict low stratus making a run at the eastern zones
in the early morning, but that likely would dissolve relatively
quickly after daybreak. Subsidence is likely to be enhanced on the
periphery of the system, so PoPs Saturday end up even lower than
today, below slight-chance in all zones. Max temps should end up
slightly cooler, just on the warm side of normal.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 120 PM Friday: The cwfa is progged to be within the far
western periphery of tropical/sub-t system circulation on Sunday. As
it stands now, based on the 12z model suite, would expect
encroachment of higher level cloud shield Saturday night and
expanding wwd on Sunday.  Given the reduced insolation and increased
chances for developing shower bands into the Carolina piedmont, have
lower MaxT for Sunday, with perhaps just mid 80s along the eastern
fringes of the cwfa.  Very well may be suppressed along and west of
the Blue Ridge to preclude any showers in the mountains, we`ll see.
The SE CONUS upper ridging with strengthen some on Monday, with very
warm air surging back NE acrs the region, bumping maximum
temperatures to above the early July climo along with a return to
more typical diurnal deep convective chances.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 145 PM Friday: Upper ridging will linger atop the region to
start off the period before beginning to breakdown in response to
Ohio or Mississippi valley energy translating eastward.  Expect
Tuesday and Wednesday to be the hottest days of the week, featuring
apparent temperatures as high as around 100 for parts of the
Piedmont. With the trend toward a less suppressed atmosphere, chancy
type pop for Tuesday will increase to likely probabilities for
showers and storms on Wednesday.  The eastern CONUS will continue to
transition to a more robust and dynamic looking pattern through the
latter half of the workweek resulting in the potential for numerous
showers and thunderstorms each day.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: E to NE flow will continue around the
southwestern side of the surface high that was anchored over the
Northeast and Mid-Atlantic. Winds have gradually diminished over
the past hour or two and the 15-18 kt gusts that was observed
during the afternoon has already subsided with the loss of daytime
heating. Speeds should generally decrease to 5 kt or less after
sunset. AVL and HKY the most likely for winds to go light and
variable (or calm) for much of tonight. VFR is still forecast
for all TAF sites tonight, but there is an outside chance (20
percent) for MVFR CIGs at CLT late tonight into the first half
of the morning when a stratus deck advances inland.  However,
most guidance keeps the western edge of this marine layer about
50-75 miles from CLT. Limited potential for valley/river fog late
tonight. Similar conditions expected on Saturday with few to sct
cumulus deck around 5-7 kft as well as high-level cirrus. The
E-NE flow will be as strong, if not 1-2 kt stronger, resulting
in sustained speeds between 8-13 kt.  Gusts of 15-20 kt are most
likely between 15z-23z when daytime mixing is strongest. There is
a risk for a due E wind to develop at CLT Saturday afternoon like
it did this afternoon. Not expected anything more than a rouge
storm in the mountains on Saturday.

Outlook: Chances for showers and storms will increase across
our area on Sunday and early next week. Depending on the track
of Tropical Depression Three, the western periphery of the outer
rain bands could approach eastern terminals, including CLT late
Saturday night and Sunday. While the heaviest rain with this system
is still expected to stay east of us, MVFR restrictions would be
possible in heavier showers. Fog and/or low stratus will also be
possible each morning, mainly in the mountain valleys, as well as
near lakes and rivers.

&&

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

&&

$$

SYNOPSIS...CSH
NEAR TERM...JK/Wimberley
SHORT TERM...CSH
LONG TERM...CSH
AVIATION...JK