GSP Forecast Discussion
394
FXUS62 KGSP 252237
AFDGSP
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
637 PM EDT Sun Oct 25 2026
.WHAT HAS CHANGED...
A Frost Advisory was issued for Sunday night for portions of the
NC mountains which have not already been "turned off" due to a
prior freeze.
Updated the aviation discussion for the recent 00Z TAF issuance.
&&
.KEY MESSAGES...
1. Patchy frost is expected to develop tonight across much of
the NC mountains and some portions of the NC Foothills. A Frost
Advisory has been issued for those mountain zones that have not
already been turned off for the season following a prior freeze.
2. Benign weather still looks to continue early through next
weekend. The next chance for rain may arrive by next Sunday,
but confidence is limited.
&&
.DISCUSSION...
Key message 1: Patchy frost is expected to develop tonight across
much of the NC mountains and some portions of the NC Foothills.
A Frost Advisory has been issued for those mountain zones that have
not already been turned off for the season following a prior freeze.
A stout z500 ridge now extends from the Gulf Coast all the way
north to the Great Lakes, with a 1035mb surface high centered over
the NJ coast continuing to support weak cold-air damming across
the western Carolinas. Below-normal temperatures and light winds
overnight tonight are expected to develop as a result of excellent
radiative cooling conditions, and this should contribute to patchy
frost developing across the NC mountains, and even some parts of
the NC foothills along the I-40 corridor. Although coverage is
expected to be limited based on the current temperature forecast,
there would appear to be some potential for temperatures to drop
a couple degrees lower-than-forecast owing to an excessively-dry
atmospheric column. As a result, a Frost Advisory has been issued
for those zones across the NC mountains that have not already been
"turned off" for the season based on a prior freeze...which includes
most of the mountains south of I-26, as well as Burke and Caldwell
Counties, along the I-40 corridor.
Key message 2: Benign weather still looks to continue early through
next weekend. The next chance for rain may arrive by next Sunday,
but confidence is limited.
The general consensus among model ensembles remains for upper
ridging to remain in place through at least Tuesday or Wednesday,
before gradually deamplifying through the end of the week. The
surface pattern will similarly remain stagnant, with the present
sfc high gradually modifying and breaking down through Tuesday,
before being reinforced by a new cP air mass on Tuesday night or
early Wednesday.
As for fire concerns, the dominant solution in long-range ensembles
now features any weak reinforcing frontal boundary sliding
through the area Tuesday night. As a consequence, it`s looking
more and more likely that any stronger low-level winds which might
contribute to low-end fire danger issues will be unable to mix down
due to the unfavorable diurnal timing...so although both Tuesday
and Wednesday look like they could see afternoon RHs in the 30%
range in some locations, confidence is increasing that true
fire danger issues will not materialize.
Another reinforcing cold front is expected to arrive over the
weekend, likely crossing the region from the north, re-establishing
cold-air damming across the area. The breakdown of the upper
blocking pattern, however, should finally allow better upper
dynamics to arrive, and ensembles are in "okay" agreement that an
uptick in low-level isentropic ascent may finally bring some rain
to the region by the end of the seven-day forecast period.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: VFR conditions will prevail at all
terminals through the TAF period. Afternoon fair weather cumulus
will dissipate over the next several with a relatively quiet
overnight period expected. Patchy valley fog cannot be ruled out at
KAVL or along rivers at KHKY. Any patchy fog will quickly mix out
after sunrise with a continuation of VFR Monday. Winds will be light
out of the north/northeast.
Outlook: Mostly VFR conditions are expected all week. Mountain
valley fog and low stratus will be possible each morning.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...Frost Advisory from 2 AM to 8 AM EDT Monday for NCZ051-052-058-
059-062>065-501>504-506.
SC...None.
&&
$$
MPR/TW
NWS GSP Office Area Forecast Discussion
