112
FXUS62 KGSP 041755
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
155 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 noon Independence Day: 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.

Invest AL92 looks not to have any direct sensible impacts on our
CWA thru the period. 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
lowered 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 THURSDAY/...
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 /18Z FRIDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Breezy winds this aftn and evening at all
sites except KAVL, generally NE`ly but possibly closer to due E
at times. KAVL looks more likely to be SE thru the aftn and then
go VRB for the evening. Elsewhere winds remain NE`ly tonight but
become light. VFR expected at all sites thru the period, with
diurnal cu today and Sat at 050-070. Chance of SHRA/TSRA much too
low to mention. Valley/river fog likely kept at bay tonight by low
crossover temps and the light winds. However, easterly flow and
Atlantic moisture may lead to low stratus developing east of KCLT
near daybreak Sat, so fcst trends will need to be monitored in
that sense. Slightly breezier conditions expected Sat aftn with
circulation tightening around coastal low, although no direct
impact expected to the terminals otherwise.

Outlook: Convective coverage is expected to increase across our
area on Sunday and early next week. Fog and/or low stratus will
be possible each morning, mainly in the mtn valleys, as well as
near lakes and rivers.

&&

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

&&

$$

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