871
FXUS65 KSLC 112159
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
259 PM MST Tue Nov 11 2025

.SYNOPSIS...High pressure remains in place ahead of an incoming
system through Friday. Southwest winds develop across the area as
the system approaches, increasing in magnitude through Friday.
Valley rain and high elevation snow are expected to impact the
forecast area Friday through the upcoming weekend.

&&

.DISCUSSION...Key Points:

- Ridging persists through Friday ahead of an incoming Pacific
  system which will bring valley rain and accumulating snow to
  most location across Utah and southwest Wyoming.

- Gusty winds develop across northern and western UT Thursday
afternoon, lasting through Friday evening.

- An active upper air pattern appears to continue following this
system resulting in more unsettled weather across the forecast area
into next week. Considerable uncertainty exists with how this will
unfold.

Ridging persists across the intermountain western U.S. as a longwave
upper trough begins its approach to the West Coast. During its
approach, a lobe of vorticity breaks off from the mean flow spurring
cyclogenesis resulting in the development of a cutoff low. This low
is forecast to dive south toward Southern California before rapidly
ejecting northeast as it attempts to phase back into the mean flow.
As this occurs, the pressure gradient will tighten resulting in
breezy southwesterly winds across northern and western UT as early
as Thursday afternoon. Winds are expected to remain sub-advisory
with ensembles indicating a <20% chance across the West Desert of
reaching or exceeding advisory criteria at this time.

Unfortunately, this setup is the solution that was considered the
other day where the majority of our forecast area is less favored
for accumulating snowfall across higher elevations. As the system
has continued to trend further south with each forecast cycle,
snowfall amounts have trended lower areawide. With the more
southerly track and the development of the cutoff low, 700mb
temperatures will remain slightly warmer than necessary for ample
snowfall accumulation across higher elevations (generally -3C to -4C
at 700mb). This will cause snow levels to hang around ~9000ft Friday
during the onset of precipitation across the majority of the area.
Snow levels are expected to drop later on Friday into Saturday
morning, though only to around 8000-8500ft. As this is a cutoff low
compared to a more defined longwave trough, colder air will not be
dragged south nearly as much with a cutoff low as compared to the
latter. Lastly, forcing will remain weaker given the southern track
yielding a much less robust setup compared to forecasts prior to
this cycle.

Some uncertainty still exists with this upcoming system with the
northern extent of where the cutoff low ejects across the forecast
area. Around 40% of ensemble members support a track that is
slightly further north, which could provide a slight increase in
ascent with brief northwesterly flow. The other 60% of members
support the southerly track that has been previously discussed. If
this northern track were to occur, there may be more accumulating
snowfall across higher elevations within the forecast area. However,
if this storm continues to trend further south, the lower end of
accumulating snow guidance may be realized. A large spread exists
among the 25th-75th NBM percentiles, such as the range for Alta
sitting around a trace to 9" of snow and Brian Head ranging from a
trace to 6" of snow.

Following the passage of a cold front, Sunday will see temperatures
across the area return to seasonal normals across the majority of
the area. In fact, lower Washington County may see temperatures 5-10
degrees below seasonal normals. Temperatures continue to cool
somewhat with the long-term temperatures remaining heavily dependent
on an uncertain forecast following Saturday regarding the pattern
that develops following this upcoming system.

Not all hope is lost quite yet as the forecast following this storm
begins to diverge amongst ensemble members once again. The GFS suite
tends to favor a southern track with the development of more cutoff
lows next week while the EURO suite favors a more northern track
following this upcoming system, albeit somewhat weaker. If the GFS
solutions were to verify, southern UT would benefit the most with
favorable forcing and more abundant moisture available. With the
EURO solutions, the majority of the forecast area would benefit as a
whole with multiple instances of weaker troughs diving NW to SE
capitalizing on leftover moisture from this upcoming system and
providing multiple instances of northwesterly flow. Clusters remain
split regarding these outcomes with ~55% generally favoring lower
500mb geopotential heights with an active northern stream while the
other ~45% favors higher 500mb geopotential heights within the
northern stream favoring the southern track cutoff low pattern. As
such, considerable uncertainty remains with this forecast past
Saturday.



&&

.AVIATION...KSLC...VFR conditions prevail at the terminal through
the TAF period under dry conditions and gradually increasing high
cloud cover overnight. Light northerly winds will transition to
light southeasterlies around 03z. Any cigs should remain above 12kft
agl through at least noon tomorrow.


.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions persist for all
regional terminals through the TAF period. Light, generally terrain
driven winds for all terminals today, with any moderate gusts at
KEVW diminishing around sunset. Increasing high clouds are expected
to enter the CWA from the west beginning tomorrow morning.

&&

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

$$

PUBLIC...Worster
AVIATION...Verzella

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