Area Forecast Discussion
Issued by NWS Greer, SC

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083
FXUS62 KGSP 200549
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1249 AM EST Thu Nov 20 2025

.SYNOPSIS...
A warm and increasingly moist air mass remains in place over our
region through the weekend. Rain chances will be highest over the
mountains late this week as low pressure tries to organize to the
west of our area. Drier air filters in late in the weekend and into
the early part of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1220 am Thursday: A split flow upper air pattern will be
in place over the Conus through the near term...with a northern
stream trough brushing the Great Lakes tonight, while the first
in a series of southern stream short wave troughs will eject from
the Four Corners later today. These features will conspire to
flatten a ridge just west of the Appalachians. Meanwhile, a weak
frontal boundary is currently draped across the extreme western and
southern part our our forecast area, with weak NE flow having
developed across much of the CWA. Resultant weak dry air advection
should preclude development of widespread fog this morning, but
patchy fog is likely in the vicinity of the boundary and across the
mountain valleys.

Otherwise, lowering heights/partial thicknesses and weak NE low
level flow will shave a few degrees off of yesterday`s temps today,
but maxes will still be around 10 degrees above climo. As heights
fall to our west tonight, the broad baroclinic zone across the
region will become activated, with frontal boundary lifting north
across our area as a warm front. Showers and a few thunderstorms are
likely to impact mainly the mountains tonight into early Friday,
with mostly 40-50% chances east of the mountains and north of I-85.
Any actual beneficial rainfall with this activity will be spotty.
Min temps will remain very warm in the elevated dewpoint/
increasingly cloudy and warm sector-ish regime.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 1223 AM EST Thursday: Progressive pattern in store for
the short term as the upper ridging over the southeastern CONUS
gradually breaks down in response to an upper low getting ejected
within the mean flow of the southern stream jet that`s draped
from the Desert Southwest through the central CONUS and into the
Northeast. Weak return flow will develop as a warm front will be in
the midst of lifting north and placing the CWFA into the associated
warm sector. DPVA and the presence of the warm front may keep a few
lingering showers to start the day Friday before dissipating. The
upper low will shift across the Mid-MS Valley Friday night and
eventually over the central/southern Appalachians on Saturday. An
uptick in low-level WAA continues Friday night into Saturday before
the occluded front moves across the area later Saturday. Ahead of
the front, isolated to scattered showers across the region and a few
thunderstorms (mainly south/east of I-85) may develop throughout the
morning hours Saturday, but can`t rule out some of this activity
sticking around into the afternoon hours, especially across the
mountains. Drier air filters in behind the front Saturday night,
with clearing skies. Record warmth is expected as afternoon highs
both Friday and Saturday with low-level WAA and anomalously high
thicknesses in place. Most locations are forecast to be in the low
to upper 70s, with some Piedmont locations reaching 80. With the
very warm and moist airmass in place and elevated cloud cover,
expect overnight lows to run 15-20 degrees above normal Friday,
while cooler and drier air filters in behind the front for Saturday
night. In this case, overnight lows Saturday should only be 8-12
degrees above normal.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 1243 AM EST Thursday: Closed upper low will be centered over
the Four Corners region at the start of the forecast period, while
weak ridging builds over the area by the early part of next week. A
cooler and drier post-frontal regime will be in place Sunday and
Monday as temperatures end up 5-10 degrees above normal. Better
return flow enters the CWFA Tuesday as the aforementioned closed
low opens up and ejects across the central CONUS Monday night
across the Great Lakes region Tuesday into Tuesday night. The
associated surface low is shown occluding as surface cyclogenesis
develops from another closed upper low that moves into the Upper
Great Plains Tuesday. The trailing front will reach the region
towards the middle part of next week. QPF response varies amongst
model guidance starting Tuesday through D7, but the pattern looks
to become more active as we get closer to the Thanksgiving Holiday
as PoPs elevate in response. Temperatures should hold steady at
around 5-10 degrees above normal through much of the extended
forecast period.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: Low level moisture has increased
significantly over the past 24 hours, so there is increasing
potential for low clouds and fog overnight. At the same time,
a weak NE flow has become established north of a weak frontal
boundary across much of the eastern half of the Terminal Forecast
Area. This is pushing slightly drier air back into the area. As
such, the probability of widespread restrictions later this morning
appears somewhat low, and mostly VFR conditions are forecast to
continue through much of this forecast period. The only exceptions
are that tempo MVFR fog along with FEW/SCT IFR cloud layers are
advertised at KAND, KAVL, and KHKY...generally between 10-14Z. Can`t
rule out brief IFR restrictions, especially at KAND/KAVL, but the
probability is low.

Otherwise, light NE winds should spread to most terminals by
sunrise, remaining through the day before becoming light/variable
this evening. The aforementioned front is expected to become
activated as a warm front that will lift north across the area
tonight. This will bring increasing chances for showers, mainly
from late evening on. Prob30s for -SHRA are carried at all sites
during this time frame.

Outlook: Mostly VFR through the end of the work week, albeit
with increasing potential for early morning fog/low stratus. The
next cold front is expected to bring shower chances and possible
restrictions Fri night into Sat. Drier conditions return early
next week, although there will remain some potential for mountain
valley fog/low stratus each morning.

&&

.CLIMATE...
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      76 1942     20 1914     61 1985      9 1914
   KCLT      79 1942     37 1914     61 1906     18 1951
   KGSP      78 1942     38 1901     59 1985     19 1903
                1896                    1931



RECORDS FOR 11-21

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      76 1994     24 1937     60 1931     11 1914
   KCLT      78 1942     38 1937     64 1991     19 1914
                            1879
   KGSP      78 1942     38 1914     64 1991     17 1914



RECORDS FOR 11-22

               MAX TEMPERATURE         MIN TEMPERATURE
  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      74 1940     32 1937     57 1934     15 2008
                                                    1937
   KCLT      76 2011     38 1929     65 1883     13 2008
   KGSP      77 2011     38 1937     58 1953     18 1914

&&

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

&&

$$

SYNOPSIS...CAC
NEAR TERM...JDL
SHORT TERM...CAC
LONG TERM...CAC
AVIATION...JDL
CLIMATE...