458
FXUS65 KSLC 281106
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
406 AM MST Fri Nov 28 2025

.SYNOPSIS...Utah and southwest Wyoming will begin to transition
into a cooler and wetter pattern from today forward as a series of
troughs take aim at the region. Mountain snow will be expected
with each trough for a portion of Utah, and even light valley
snowfall will be within arms reach by Sunday.

&&

.DISCUSSION...The relatively weak ridge that has remained in place
over Utah and southwest Wyoming over the past few days will break
down today as a series of troughs move through the forecast area
through at least the middle of next week. Three distinct troughs
are expected to progress through the region, each with varying
impacts.

Key Points:

- An initial trough passes through the northern half of Utah and
  southwest Wyoming Friday into Saturday, with a majority of the
  moisture remaining well north of the area. Light mountain
  snowfall (northern Utah) and temperatures returning to near
  normal will be the result.

- A more moisture laden trough is expected to track into Utah on
  Sunday, bringing a more direct hit from a cold frontal boundary,
  as well as a shot of moisture to the northern third of Utah.
  There is anywhere from a 40 to 60% chance of measurable snow in
  the northern valleys on Sunday, though totals are very likely to
  amount to less than 1 inch (~90% chance). Temperatures below
  normal.

- A third trough is set to be introduced into the region sometime
  around Tuesday/ Wednesday, bringing another potential shot of
  moisture into the Utah mountains. That said, there is still a
  sizable amount of uncertainty revolving around this storm.

Early morning satellite imagery depicts a trough moving across the
PacNW region with widespread upper level moisture spreading from
southern B.C. southward through southern Utah. Over the next 24
hours this trough will dig farther southeast, with the base of the
feature pushing into northern Utah this afternoon. Lower level
moisture will increase gradually alongside the introduction of a
cold frontal boundary, helping to bring and increase in cloud
cover and eventual increase in shower activity across northern
Utah (particularly in the mountains). With the near surface
environment being quite dry, significant precipitation will not be
expected... especially with the speed of the trough. Instead,
light accumulations of snow are expected in the Bear River
Mountains, with the greatest change for valley areas being a drop
in temperatures back to near normal levels by Saturday.

Quick stabilization of the environment is expected in the wake of
this trough for Saturday, leading to dry conditions areawide.
During the day, our next trough will begin to take form over the
PacNW once again. Models are in good agreement that this trough
will take a more southerly track into the eastern Great Basin
region, helping to provide much more robust lift alongside a more
significant cold frontal passage. It should be noted that there
are still about 30% of ensemble members (majority members from
Canadian ensemble) that support a grazing trough scenario which
would favor drier and a grazing cold front. The remaining 70% of
ensembles, however, are in good agreement of anomalous low mid-
level heights over northern Utah/ southwest Wyoming, indicating
that we`ll see the associated cold air which will provide more
structured synoptic lift. This lift, combined with the moisture
laden trough, will help to kick off another shot of precipitation
across northern Utah and southwest Wyoming. With antecedent
temperatures already relatively cold and an even colder airmass
incoming, there will be anywhere from a 40 to 60 percent chance of
seeing the FIRST(!) measurable snowfall on the Wasatch Front,
Cache Valley, and Ogden Valley. Additionally, much more synoptic
support for precipitation also means that we`ll see more than 1-2
inches of snowfall for the mountainous terrain.

While still not a significant enough storm for large strides
toward building a deeper snowpack, anywhere from 4 to 10 inches of
snowfall can be expected in the central/northern Wasatch, 2 to 6
inches for the Bear River Mountains, and 3 to 6 inches for the
western Uinta Mountains can be expected (25th to 75th percentile).
That said, the low end potential for this storm (10th percentile)
still ends up being 0 inches, which is a solution that is more
favored by the Canadian ensemble suite. Odds are still favoring
decent mountain snow for northern Utah. In the less favored
central and southern Utah mountains, anticipate upwards of around
4 inches (75th percentile) with the low end still favoring 0
inches (25th percentile).

In the post-frontal environment, temperatures across Utah and
southwest Wyoming will drop to below normal levels for the first
time in a while. By Monday morning the axis of the trough will be
east of the area, leaving behind the colder airmass which will
favor below normal temperatures through the arrival of the next
trough. As mentioned in the Key Points, there is still a sizable
amount of uncertainty with this trough. In a nearly 33/33/33
split amongst guidance, the trough moving through the region will
go one of these three directions. 1) A much farther westward track
into the western Great Basin (relatively wet), 2) grazing trough
across northern Utah/ southwest Wyoming (wet for the northern
mountains), or 3) something similar to what we`re expecting for
Sunday (potentially wet areawide). With nearly equal probability
for each solution, it`s too early to call any shots BUT each
solution would favor a maintenance of below normal temperatures
and at least a shot of moisture for a portion of Utah. The
atmosphere will remain mixed well enough to keep valley inversion
out of the picture, but current model guidance is not supportive
of high confidence in a headline worthy event... just another
potential shot of mediocre snowfall amounts for the mountains.

Beyond mid-week, models diverge quite a bit with how the pattern
will evolve as 50-60% are supportive of a ridge building into
place to our west and the remaining 40-50% supportive of a
continued longwave trough pattern.



&&

.AVIATION...KSLC...Light and variable winds through 14Z will become
predominantly southerly by mid morning, then switch to northwesterly
during the 18-19Z timeframe as a dry cold front crosses the area.
VFR conditions will prevail through the TAF period.



.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will prevail
through the period at all TAF sites. A dry cold front crossing the
area this afternoon will shift winds to northwesterly across
northern Utah TAF sites, while gusty west-southwest winds persist
at KEVW throughout the day.


&&

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

$$

PUBLIC...Webber
AVIATION...Seaman

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http://weather.gov/saltlakecity