426
FXUS65 KSLC 012220
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
320 PM MST Mon Dec 1 2025

.SYNOPSIS...A storm system is on track to bring valley and
mountain snow to much of Utah Tuesday and Wednesday. A drier
Thursday is likely, with models indicating a northern mountain
snow event Friday into the weekend.

&&

.SHORT TERM (After 00Z Thursday/5PM Wednesday)...Conditions are
mostly clear and dry throughout southwest Wyoming and Utah after
the weekend storm system exited. Early Monday, remnant moisture
contributed to low stratus and fog for some locations that has
cleared. Dry and mostly clear conditions won`t continue long, as
an upstream shortwave trough slides south from Montana and Idaho.

Clouds will increase from north to south Monday into Tuesday, with
snow showers starting early Tuesday. Compared to the weekend storm
system that this one will have a similar track to, this will be
more disorganized and have less moisture. Hi-resolution models
within the HREF are lower in terms of snowfall with the 12Z runs
compared to runs before. Snow will be showery for much of
Tuesday, then pick up in intensity Tuesday into Wednesday. For
mountain routes, including Parley`s Canyon and the Cottonwood
Canyons, snow showers will be locally moderate to heavy,
particularly Tuesday afternoon into Wednesday, likely affecting
travel. There will be some limited lake-effect or lake-enhanced
snow after the synoptic snow, but similar to the last storm,
conditions will dry out quickly. Snow accumulations will generally
range from 2-6 inches throughout Utah`s mountains with locally
higher totals.

Snow levels will be low enough for valley snow for most of the
event. Valley snow accumulation will range from a trace-1 inch
for most locations, but with much of that Tuesday night into
Wednesday with temperatures in the teens and 20s, snow will be
capable of affecting the Wednesday morning commute.

Snow will taper off from north to south Wednesday, with drier
conditions into Thursday.

.LONG TERM (After 00Z Thursday/5PM Wednesday)...A strong
mid/upper ridge will gradually slide southeast from the Gulf of
Alaska over the Pacific to kick off the long term. This will set
up a pattern of persistent northwest flow aloft maintaining cool
temperatures aloft across our forecast area and maintain favorable
storm tracks for the area. On Thursday, mild conditions develop
following the departure of our mid-week storm as cool and stable
air is transported across the forecast area. Most valley locations
will reach highs in the upper 30s on Thursday, slightly below
climatological normals for this time of year.

On Friday, enhanced northwesterly flow aloft develops as a shortwave
trough ejects from the Gulf of Alaska into southwest British
Columbia, flattening the ridge as a result. Ensemble guidance
remains in great agreement with this solution, with each cluster
remaining in agreement with respect to the general flow pattern,
though slight differences in geopotential heights exist and likely
won`t have much of an impact. At the surface, flow will clock to
southwesterly drawing up ample moisture ahead of the northwesterly
enhancement. With favorable ascent expected with this impulse, a
potentially significant snowfall event appears possible across our
northern UT mountains beginning as early as late Friday night
through Sunday morning.

Warm air advection commences Friday, serving to raise snow levels
across the forecast area keeping any snowfall isolated to higher
terrain. Snow levels are expected to drop somewhat heading into
Saturday, though not by a large margin. With this type of system,
the warm air advection regime will typically keep snow levels above
valley floors yielding a relatively high-confidence forecast for
rainfall across the majority of valley locations across northern UT
this weekend. There is a small chance for some accumulations across
the Cache valley as they remain somewhat sheltered and will remain
colder overnight into Saturday, though this remains uncertain at
this time. There is also a chance that the northern Wasatch Front
could see light accumulations as well, granted overnight
temperatures cool efficiently. On Saturday, deeper moisture and
stronger ascent continue pushing into the forecast area. This is
expected to yield higher snowfall rates across our northern
mountains, tapering off into the evening as the system progresses
southeast into Sunday morning.

Through the extended, ensemble guidance keeps the general pattern in
place, though uncertainty remains surrounding the placement of the
Pacific Jet. Around 50% of ensemble members build the aforementioned
mid/upper ridge, nudging the jet slightly north thus lowering
chances for additional precipitation somewhat. Additionally, 25% of
members keep the pattern relatively the same with the final 25% of
guidance flattening the ridge further pushing the jet slightly
south, favoring precipitation chances across central and southern UT
in the extended.

&&

.AVIATION...KSLC...Prevailing VFR conditions are expected at the SLC
terminal through at least tomorrow morning. Clouds will increase
overnight and gradually lower into the morning hours. Occasional
flurries will be possible in the morning, with a less than 20
percent chance of brief MVFR conditions. Periodic snow showers
will become a bit more likely by midafternoon into tomorrow night.
Occasional MVFR to briefly IFR conditions will be possible during
this time. Otherwise, northerly winds this afternoon are expected
to switch to southerly by 02-03z this evening.

.REST OF UTAH AND SOUTHWEST WYOMING...Generally VFR conditions are
expected across most areas into tomorrow morning. However, some far
northern Utah locales may see occasional MVFR CIGS overnight.
Otherwise, scattered flurries or light snow are expected to develop
across northern Utah tonight and southern Utah tomorrow morning
which could lead to to isolated MVFR conditions. Snow showers will
then increase across northern and central Utah tomorrow afternoon
and evening which could result in periodic MVFR to briefly IFR
conditions and mountain obscurations.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

$$

SHORT TERM...Wilson
LONG TERM...Worster
AVIATION...Cheng

For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity