302
FXUS62 KGSP 021109
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
609 AM EST Fri Jan 2 2026

.SYNOPSIS...
Expect warmer temperatures today. A low pressure system brings
rain tonight and Saturday, with high temperatures trending cooler
briefly on Saturday. Dry and warmer conditions return by Sunday,
with above-normal temperatures most of next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 1111 PM Thursday:

Key Message #1: Dry weather with above normal temperatures continues
today with rain chances returning tonight and Saturday as the next
storm system moves across the area.

A pronounced northern stream trough will slide across New England
through the overnight hours with deep layer northwest flow
transitioning to flat quasi-zonal flow within a weak branch of the
southern stream. A shortwave trough is progged to be embedded within
these westerlies over the Southern Plains with a lead impulse
lifting across the Mississippi Valley. A weak surface low
associated with the lead wave will help instigate a broad area of
showers in conjunction with favorable, albeit weak, upper jet
dynamics. The surface low is forecast to track along a diffuse
baroclinic zone draped roughly along the I-20 corridor. This will
support increasing rain chances tonight into Saturday as the system
slides across the Southern Appalachians. Much needed rainfall is
expected with no hydro concerns or severe weather as the region will
remain stable within a weak in-situ CAD wedge. Temperatures will be
above normal today beneath rising heights, but will be noticeably
colder Saturday as rain cooled air established the weak CAD wedge.
Highs Saturday will range from the low 40s to low 50s, which will be
10-15 degrees colder compared to today.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 1135 PM Thu:

Key message: Dry Sunday and Monday with above-normal temperatures but
relative humidity being only moderately low.

Erosion of the in-situ wedge will continue through Saturday night,
with precip tapering off in the Piedmont by late evening, and
northwesterly low-level winds beginning to scour out cloud cover
behind the eroding cold front.  Nonetheless some stratus is likely to
linger until the beginning of the day Sunday in our more southeastern
zones, with upslope clouds also remaining near the TN border until
that moisture is exhausted during the day. Temps should rebound
several degrees from Saturday`s maxes, ending up generally 5-8 above
normal. Winds in the mixed layer are not particularly strong Sunday,
and although some afternoon dip in dewpoints is expected, RH does not
look likely to reach the critical 30% criterion for fire danger. The
post-frontal high will migrate to the Mid-Atlantic coast by Monday
morning with a low-amplitude ridge axis to our west. This will bring
back light SW flow back, offsetting the cooler start such that highs
only trend a couple degrees cooler for most of the area; winds will
be a bit breezier as well. The SW flow also appears to introduce more
moisture aloft, offsetting the afternoon dewpoint crash.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
As of 1210 AM Fri:

Key message 1: Well above-normal temperatures continue through late
next week.

Quasi-zonal 500mb flow continues across the southeastern US Tue-Wed
while subtropical ridge moves across the Gulf. At 850 mb, ridge
remains off the SE coast allowing return flow to continue such that
temperatures continue to moderate; height rises continue off the
coast thru the end of the period. Maxes return to the 60s for most of
the CWA Tuesday, reaching the upper 60s across the Piedmont
Wednesday. Values decline a bit Thursday seemingly as a result of
some models developing CAD over the area (see below).  That said,
even the NBM 10th percentile maxes are warmer than climo that day, so
it will be a warm period overall, though not likely record-setting.

Key message 2: Next possibility of rain Tue night and Wed for the
mountains. Thursday or Thursday night for the remainder of the area.

In terms of forcing for ascent, the pattern is rather murky and
ill-defined through the period, but small chances for rain do result
due to systems in our proximity. A weak shortwave moving across the
Great Lakes Tuesday night looks to turn low-level winds westerly
across the southern Appalachians, but without any appreciable
dynamics; some models spit out a small amount of QPF near the TN
border which translates to a 15-25% PoP which continues into
Wednesday in that area. Temperatures are warm enough for this to be
mentioned only as rain.  The front trailing that wave appears to
stall just north of the CWA which is why an appreciable cooldown is
not expected.

There are some model differences which crop up thereafter. The
operational GFS and many of the GEFS members suggest the building
ridge over the SE Coast will effectively hold off the next shortwave
moving across the southern Plains, keeping us dry through Thursday
night. The GDPS is stronger with the ridge and attendant sfc high
such that the Plains system leads to in-situ CAD over the area
Thursday, though still with minimal QPF. The 01/12z ECMWF is the
exciting one, with a more potent shortwave trucking across the lower
OH/TN valleys, bringing higher QPF and potentially a brush with
thunder as well. Mentionable 20-30% PoPs result for the whole CWA
late Wed night and Thu as a nod to these solutions; confidence too
low to go any higher at this point. Once again, such an event would
appear to be all rain.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: VFR conditions will prevail at most terminals
through the majority of the TAF period. High clouds continue to
increase in coverage early this morning ahead of the next storm
system. Showers are expected to increase in coverage tonight and
continue into Saturday morning. This will bring a range of
visibility restrictions along with patchy fog. Additionally,
ceilings will lower as well with MVFR to IFR becoming increasingly
common by the end of the TAF period. Winds will be out of the
southwest today and a couple gusts cannot be discounted. Winds shift
to out of the northeast tonight as an in-situ CAD wedge develops.

Outlook: Dry, VFR conditions to return Sunday, and linger through
early next week.

&&

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

&&

$$

SYNOPSIS...JCW
NEAR TERM...TW
SHORT TERM...JCW
LONG TERM...JCW
AVIATION...TW