681
FXUS62 KGSP 241054
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
654 AM EDT Sun Aug 24 2025

.SYNOPSIS...
A cold front will approach the area today from the northwest,
bringing a chance for showers and thunderstorms. The cold front will
track across the forecast area Sunday night into Monday morning,
allowing dry weather to return behind it for much of the week. High
temperatures remain warm on Monday before a cooler, fall-like air
mass develops the rest of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 654 AM EDT Sunday...Numerous showers were noted on radar
over east TN and brushing up against the NC mtns, but the showers
keep dissipating as they crest the first few ridges near the TN
state line. Think the precip chance we have on the TN border will
continue to handle the situation for the next few hours until we
can destabilize with morning heating. Kind of complicated for the
rest of the fcst area early this morning, but some patchy dense
fog has developed over parts of the NC Foothills. Think the vis
will be too variable and too short-lived to issue a Dense Fog
Advisory at this point.

For the next 24 hours, an almost-winter-looking upper pattern
with a mid/upper low centered over James Bay Canada and a trof
digging further southward over the Great Lakes and Midwest. This
feature should absorb the baggy trof feature that has plagued
our region for the past several days. A lobe of vorticity and
subtle pre-frontal trof is expected to trigger new showers and
thunderstorms over east TN early in the day, then moving over the
mtns this afternoon and organizing into a more coherent band before
coming off the mtns in the mid/late afternoon. Precip probs will
be highest on the east slopes but then tapering off to chance to
the east. Will keep precip chances going into the middle part of
the evening, longer than indicated by the NBM and more like the
HRRR, as the band of precip will probably still be ongoing right
at 00Z Monday along our eastern border. In terms of severe weather
potential, nothing particularly scary looking in the guidance,
but the RAP indicates about 2000 J/kg of muCAPE east of the mtns
this afternoon to go with about 25 kt of deep layer shear, so a
few strong/severe cells would not be surprising. Storms should
be moving right along which should keep the flash flood threat
low. The primary cold front should remain to the west of the mtns
today, so a SW flow ahead of the boundary will allow temps to
rebound to within a category of normal this afternoon. The main
cold front is expected to push east across the mtns tonight as a
short wave axis moves overhead, and should probably be somewhere
over the eastern part of the fcst area by daybreak on Monday. Not
far enough east to really bring the new air mass across the mtns,
so low temps tonight will be very similar to this morning. The
air should at least feel a little drier, though.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 100 AM EDT Sunday: Very strong closed upper low centered
over the Hudson Bay will bring falling heights and cyclonic flow
aloft over the southeastern CONUS by Monday. The attendant cold
front should complete a full fropa across the CWFA by daybreak
Monday or shortly after. A very dry airmass will filter in behind
the front as dewpoints tank into the 40s and 50s, bringing in our
first real taste of Fall. CAA behind the front will be delayed on
Monday as a downslope component keeps temperatures in the low to mid
80s east of the mountains for afternoon highs. Cyclonic flow aloft
remains in place through the remainder of the forecast period with
a surface high moving in from the northwest. Much drier conditions
will be noticeable and persistent north-northeasterly winds aids
the post-frontal regime. Dewpoints will remain in the 40s and 50s
each day, with overnight lows running 5-10 degrees below normal
Monday night. CAA settles in for Tuesday with mostly sunny skies
and afternoon highs 5-10 degrees below normal, while overnight
lows end up 6-12 degrees below normal. Enjoy our taste of Fall!.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 145 AM EDT Sunday: Cyclonic flow aloft remains in place
going into the middle part of the week, while surface high sets
up shop over the Mid-Atlantic and OH Valley. Model guidance have
picked up on a reinforced shortwave riding the base of the upper
troughiness that will swing across the area, with some weak moisture
return. Not excited about the potential as the dry airmass holds
strong, but NBM has introduced a slight chance PoP in the western
zones overnight Thursday as a result. Otherwise, the upper trough
gradually flattens out by the end of the forecast period. With
the surface high offshore, weak moisture transport may begin to
filter in by the upcoming weekend. This will help to increase PoPs,
but with the antecedent dry airmass, confidence is low at this
time on coverage, if any at all. Otherwise, temperatures remain
a 5-10 degrees below through much of the extended with dewpoints
in the 40s and 50s, with a return to the lower 60s outside of the
mountains by the end of the week.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: The immediate problem is the patchy dense
fog across parts of the NC Foothills, including KHKY, where a
VLIFR restriction will be included for the first hour. The other
problem spot is KAVL where a persistent LIFR stratus deck has
formed in the valley. The fog and low stratus should dissipate by
mid morning. Guidance has been relatively consistent with showing a
broken band of convection moving across the region ahead of a cold
front this afternoon.  Confidence in the coverage has increased
enough to go with a TEMPO over the Upstate where the HRRR moves
a more coherent band of storms, but will leave KCLT at a PROB30
for the time being. The activity should push off to the east well
ahead of a cold front by mid-evening, with the actual front and
wind shift arriving late tonight.

Outlook: Drier conditions will return early Monday and continue
through most of next week. Fog and low stratus may develop each
night, mainly in the mountain valleys.

&&

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

&&

$$

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