698
FXUS62 KGSP 071026
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
626 AM EDT Tue Oct 7 2025

.SYNOPSIS...
High pressure lingers over the area today keeping low rain chances
and above normal temperatures around. Above normal temperatures
linger on Wednesday despite a cold front bringing isolated to
scattered showers and thunderstorms to the area. Drier and cooler
conditions return behind the front the rest of the week, with below
normal temperatures returning Thursday into Friday before a warming
trend develops this weekend into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 621 AM EDT Tuesday: The low clouds over the mountains and
foothills should stick around through the mid- to late morning hours
before better daytime mixing gets going as better low-level WAA
filters in and allows for the cloud deck to scatter. Locations where
the clouds have not develop are now witnessing patchy dense fog with
dewpoints in the low to mid 60s and light winds, enough radiational
processes has caused localized areas of dense fog just before
daybreak as dewpoint depressions tighten. As a result, an SPS has
been issued for patchy dense fog in portions of northeast Georgia,
Upstate South Carolina, and the North Carolina Piedmont until 9 AM.
With the presence of an extensive low cloud deck and elevated
dewpoints, morning lows will run 4-8 degrees above normal.

Low cloud cover continues to remains locked in over the area in the
presence of a lingering in-situ wedge as a surface high continues to
drift further offshore over the western Atlantic in response to a
departing upper ridge. Steady moist upglide is present, which is
helping to keep the residual wedge in place despite gradually losing
its synoptic support as the surface high moves further out the sea.
All of this is in response to a digging upper trough that will
propagate from central Canada and the Northern Great Plains to
Atlantic Canada and the northeastern CONUS by the end of the
forecast period. An associated cold front will shift towards the
region through the forecast period and be in the midst of shifting
across the NC/TN border by daybreak Wednesday.

Model guidance are in agreement with the low-level (including at
the surface) flow turning south-southeasterly by the afternoon
hours as the lingering wedge seems to lose its battle with daytime
mixing and low-level WAA. Isentropic lift is still present during
peak heating as well, which model guidance have picked up on the
development of WAA driven showers across portions of the Piedmont
area. In this case, placed a slight chance PoP during the afternoon
hours, but coverage will be isolated. May take some time for the low
clouds this morning to scatter out, but once insolation reaches the
surface, it won`t take long for temperatures to rise and thus,
afternoon highs are expected to rise 3-6 degrees above normal,
especially with anomalously warm thicknesses in place.

Changes really take place overnight tonight as the first band of
showers associated with the cold front will approach the mountains
tonight and shift east across the rest of the CWFA during the
beginning portions of the short-term period. As mentioned at the
beginning of the discussion, the front should be near the NC/TN
border by the very end of the near-term, but it almost seems as
if the latest guidance are showing hints of an anafront, which
displaces the precip behind the actual front. In this case, the
cooler air at the surface would undercut any stronger updraft from
developing within the band of showers overnight. Also, the better
forcing for ascent and deep layer shear resides north of the area,
so all indications suggest that the initial band of showers will
lack any real convective elements. Otherwise, widespread cloud
cover and dewpoints remaining elevated will keep overnight lows
5-10 degrees above normal.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 130 AM EDT Tuesday...

Key Messages:

1) A Cold Front Brings Isolated to Scattered Showers and
Thunderstorms on Wednesday

2) Breezy Northeast Winds and Drier Conditions Develop Behind the
Front Wednesday Night, Lingering through Thursday Night

3) Temps Remain Warm and Above Normal on Wednesday with Much Cooler
and Below Normal Temps Returning Thursday

Weak upper troughing remains overhead through the short term.
Meanwhile, at the sfc, a cold front tracks over the forecast area
Wednesday morning and afternoon before dry high pressure builds in
behind the departing front Wednesday evening into Thursday night
bringing drier conditions and much cooler temperatures. Breezy NE
winds will also develop behind the front Wednesday night into
Thursday night, ranging mostly from 15-25 mph.

00Z CAMs are not showing much in the way of coverage of convection
on Wednesday, depicting only isolated to scattered (at best)
activity. NBM depicts mostly chance PoPs (35% to 50%) across the
forecast area, although low-end likely PoPs (55%-60%) are in place
mainly along/east of I-77. PoPs on Wednesday may need to be lowered
in future updates if the CAMs continue showing anemic coverage of
convection. Most of the 00Z CAMs show the bulk of convection pushing
east of the forecast area by Wednesday afternoon but the 00Z NAMNest
appears to be the slow solution, keeping convection around across
the southern zones through Wednesday evening. With the NAMNest being
the outlier, only maintained low-end chance PoPs after 8pm
Wednesday. 30-35 kts of deep layer shear will be in place ahead of
the front with 00Z CAMs showing ~1,000-1,500 J/kg SBCAPE developing
east of the mountains during peak heating Wednesday. So, could not
entirely rule out an isolated strong storm or two east of the
mountains, but the severe weather threat should remain low with such
limited coverage of convection expected. Above normal highs return
Wednesday despite mostly cloudy skies and isolated to scattered
convection. Lows Wednesday night will end up 5-9 degrees above
normal thanks to lingering cloud cover. Highs on Thursday will be ~5-
10 degrees cooler across the mountains and ~10-15 degrees cooler
east of the mountains compared to Wednesday, ending up ~5-8 degrees
below normal. Lows Thursday night will end up near normal to a few
degrees below normal. With lows falling into the mid 30s across
portions the NC mountains Thursday night, patchy frost may develop.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 200 AM EDT Tuesday...

Key Messages:

1) Dry Conditions Stick Around as High Pressure Remains in Control

2) Breezy Northeast Winds Linger through the Weekend

3) Highs Remain Below Normal Friday before a Warming Trend Develops
this Weekend into Early Next week

Upper troughing remains in place on Friday before an upper low
strengthens and possibly cuts off from the main flow over/near the
eastern Carolinas this weekend. However, guidance is split regarding
the exact evolution and track of the low this weekend into early
next week. At the sfc, high pressure will remain in place over the
western Carolinas through early next week while a coastal low
develops off the Carolina coast late this weekend into early next
week. Again, guidance is not in the best agreement regarding the
exact evolution and track of this coastal sfc low, but it appears
(for now) that the western Carolinas should remain dry through the
period with the bulk of the moisture associated with the low
expected to remain east of the CWA. With this being said, there`s
still time for things to change so will continue to monitor the
forecast closely in the coming days regarding the evolution/track of
both the upper low and coastal low. For now, NBM keeps the area dry
which seems reasonable given the latest model guidance. Breezy NE
winds will linger through the weekend before lighter winds return
early next week. Highs on Friday will be similar to Thursday, ending
up ~4-8 degrees below normal. Lows Friday night will end up near
normal. A warming trend develops this weekend and lingers into early
next week. Highs will end up near normal to just below normal this
weekend, trending a few degrees above normal early next week. Lows
this weekend into early next week will end up a few degrees above
normal.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: MVFR/VFR cigs remain in place across KHKY
and KAVL, while some clearing across the Upstate sites and KCLT has
allowed for a LIFR/IFR low stratus and fog to develop. This will
limit fog development, but with good moisture in place, patchy dense
fog is possible at the aforementioned TAF sites as well. Placed a
TEMPO for either IFR/LIFR cigs at all sites  through 13Z-14Z as
guidance suggest that cigs and vsbys will begin to lift and scatter
after 14Z. Any restrictions in place will gradually improve after
daybreak as all sites should return to VFR by the early afternoon
hours, so reflected a gradual improvement after daybreak at all
sites. VFR conditions will prevail through the rest of the forecast
period, but changes will be on the horizon with an incoming cold
front. Winds will be light through the period with a steady south-
southeasterly component at all sites after daybreak and remain this
way through the end of the TAF period. Can`t rule out an isolated
shower during the period, but confidence is too low on location and
timing for a TAF mention at this time outside of the initial band of
showers with the incoming cold front at KAVL.

Outlook: A cold front increases rain chances and restrictions,
through Wednesday night before drier conditions return for
the remainder of the week/weekend. Can`t rule out morning low
stratus/fog in the mountain valleys each day, but chances will
be lower than normal after Wednesday night through the rest of
the week/weekend.

&&

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

&&

$$

SYNOPSIS...AR
NEAR TERM...CAC
SHORT TERM...AR
LONG TERM...AR
AVIATION...CAC