NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before the first event at Jan 10, 6:44 AM EST, 5 hours 16 minutes earlier.
Area forecast discussion, Jan 10, 6:44 AM EST, 5 hours 16 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
644 AM EST Sat Jan 10 2026
.SYNOPSIS...
Temperatures remain unseasonably warm today. Widespread rainfall
ongoing will continue through today and into tonight, until a cold
front pushes through the area and dries us out. Temperatures return
to near- or even below-normal Sunday into early next week under
building high pressure.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 134 AM Saturday:
Key Message 1: Widespread showers and few embedded thunderstorms
through late afternoon, with a non-zero threat for a severe
thunderstorm across northeast GA and Upstate SC this afternoon.
Deep moisture and forcing will continue to work together to produce
a wide band of shower activity through daybreak, streaming up from
the SW and riding along/ahead of a SW-to-NE oriented boundary to
our west. There could be a few embedded isolated thunderstorms
within this broad area, reference the recent lightning flash in
western Elbert County GA. There are two minor concerns as this
activity slowly translates eastward with the boundary today.
First is the threat for excessive rain. Note how the pertinent
Excessive Rainfall Outlook marginal risk area has been gradually
shrinking as evidence of the low chances of getting enough rain to
cause problems. Rainfall rates thus far have remained eminently
manageable and our QPF remains in the 1-1.5 inch range through
tonight. With as dry as it has been it is hard to imagine this rain
being anything other than beneficial and the amounts are unlikely
to produce flooding, but elevated stream flows can be expected,
particularly in the SW-facing slopes. We will continue to monitor.
Second is the threat for an isolated severe thunderstorm
later today. Buoyancy will remain minimal and elevated through
late morning, so anything more than an isolated storm is not
expected. However, there will be a window of opportunity from
late morning through late afternoon when some weak sfc-based CAPE
could develop along/S of the I-85 corridor, perhaps in the 100-300
J/kg range. Meanwhile, as a 40-50kt low level jet moves overhead,
hodographs will elongate and upwards of 40 kt of effective bulk
shear could develop. This puts us in the realm of the "non-zero
threat" mainly for a brief weak tornado. Note there is much
more working against this than for it at this time, and of note
is the 00Z HREF which fails to develop any rotating updrafts or
interesting reflectivity structures in any of the CAM output. Either
the unfavorable alignment of the shear being parallel with the
boundary or the lack of buoyancy will be the limiting factor,
or both. This will also be monitored for signs of model guidance
picking up a favorable trend.
Key Message 2: Breezy conditions expected with a cold front passage
east of the mountains this afternoon and in the wake of the front
tonight across the mountains, though it should fall short of
Advisory criteria.
Not much change to earlier thinking with the wind speeds with
our frontal passage. Unless we get more convection to bring the
stronger winds to the sfc this afternoon, the gusts will fall
well short of Advisory criteria. Tonight, with the cold advection
behind the front, winds will pick up across the mtns but again
should stay below criteria at all but the highest peaks.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 1136 PM EST Friday...
Key Message #1: Breezy conditions on Sunday behind a departing
cold front, resulting in low-end fire weather concerns.
By Sunday morning, the cold front should be located solidly to
our east, with low-level CAA underway across the forecast area.
This will contribute to widespread gusts in the 25-30kt range
through at least Sunday afternoon, when the core of postfrontal
CAA slides through the region. Across the high terrain, where
little to no mixing will be required to tap into strong flow in the
925-850mb layer, gusts could surge as high as 40kts, toying with
Advisory Criteria but not quite getting there at most locations.
These gusty conditions will intersect rapidly-drying dewpoints as
postfrontal air digs into the area...and RH is expected to fall
below 35% Sunday afternoon. RH is known to tank in localized areas
in such regimes, so lower values certainly can't be ruled out;
however, given Saturday's rainfall (see near term discussion above)
it appears unlikely that fuels will reach critical moisture...so
fire danger appears limited at this time. In any case, as CAA
tapers off Sunday evening, so too will gusts.
A secondary, related issue will be the potential for NW flow snow
flurries the first part of Sunday, mainly across the NC-TN border.
Deterministic guidance indicates that only a fairly shallow layer
of moisture will remain in place past 12z Sunday...mainly north
of the French Broad Valley. Given the strength of low-level
CAA, one would expect this moisture to get scoured out fairly
quickly...with flurries over by late afternoon. Little to no
accumulation is expected.
Key Message #2: Dry and cold conditions persist Sunday night
and Monday.
Lingering, weakening CAA will continue into Sunday night as
progressive surface high pressure expands across the U.S. Southeast.
Lows should drop to 1-2 categories below climo Sunday night
(in the mid-20s for the low terrain, and into the upper teens at
higher elevations) before only back into the upper 40s across most
of the area on Monday. Excellent daytime mixing should develop
Monday afternoon, tapping into a deep dry layer aloft; however,
tame winds across the entire area should limit fire danger issues.
By Monday evening, into the overnight, the center of...increasingly
ill-defined...high pressure will shift to our east; as a result,
we'll find ourselves back in a SW flow regime with subtle low-level
WAA developing overnight and prompting an increase in low-level
thickness. As a result, lows Monday night should be up to a
category higher than on Sunday night...but still below normal.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 1229 AM EST Saturday...
Key Message #1: Quiet conditions expected through mid-week.
One more day of borderline/critical RH is expected Tuesday, but
again sans much of a breeze fire weather issues should be limited.
In general, a strengthening SW flow / WAA regime is expected
Tuesday and Wednesday, as the upper pattern again becomes amplified
across the eastern CONUS...with a series of z500 waves developing
within the northern stream and digging across the Midwest into the
region through Tuesday night. In general, moisture and cloud cover
should increase during this time, but little if any rainfall can
be expected through mid-day Wednesday.
Key Message #2: Active weather returns the second half of the week,
with unusually low predictability.
The forecast gets increasingly difficult-to-parse by Wednesday
night. Guidance depicts the presence of a pre-existing coastal
front just off the SC coastline, even while multiple upper vort
lobes phase together and prompt the development of a deep, high-
amplitude trough axis over the central Ohio Valley. As this
feature migrates eastward, it should interact with the surface
boundary; virtually all the long-range ensembles depict some
flavor of cyclogenesis on Thursday. The consensus, however,
is that this will take place a tad too far east to get much good
moisture return into the area (which is to say that we'll be on
the dry side of this system)...severely limiting winter precip
potential, except in the mountains, where colder temperatures will
lend themselves to accumulating snowfall. Generally think accums
will stay below advisory criteria, though the usual spots in the
Smokies could get close. Depending on exactly how far east the
coastal low sets up, and how quickly the upper trough axis crosses
the area, there's potential for another round of flurries across
the northern third of the CWA, mainly along and north of I-40,
on Thursday, as depicted in a few GEFS and CMC-GEPS members.
An important takeaway here is that there's still quite a bit of
room for change. With such an active, unsettled synoptic pattern,
and still some 5 days to go until we get there, it's very difficult
to pin down important details at this stage.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Variable vis and ceiling will be the rule
through the better part of the morning hours as moisture lifts
over a weak boundary located inconveniently close to I-85. That
puts several terminals in a position where vis and ceiling could
come in-and-out from LIFR to the upper end of MVFR depending
on heavier showers. There will also be brief VFR holes, but
VLIFR seems unlikely. The TAFs will attempt to account for the
prevailing condition being IFR or LIFR one way or the other through
midday or so. Sfc winds will be light/variable, so improving
flow above the sfc could introduce some LLWS for the start of
operations. Eventually this morning, the main front will cross
the mountains and move east across the fcst area, so the variable
restrictions are likely to continue into the early afternoon. It is
not clear that we will get much in the way of thunder, so that was
included only at KAND and KCLT which have the best shot of seeing
the necessary instability. The front will bring stronger SW sfc
winds with occasional gusts. The recent guidance still lifts the
ceiling to MVFR this afternoon once the front moves in, so this
improvement was indicated in the new fcst, but it is possible
that IFR could linger through the afternoon at some locations,
particularly KHKY which is typically the last place to lose the
lower clouds. Note that the passage of the front will bring the
wind around to more W to WNW this evening. By mid-evening, most
terminals should have improved to VFR.
Outlook: Flight restrictions should end Saturday night but gusty
winds continue through Sunday night. Dry high pressure will bring
VFR for Monday and Tuesday. A cold front could bring precipitation
and restrictions Wednesday.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
SYNOPSIS...MPR
NEAR TERM...PM
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...PM