769
FXUS65 KSLC 032129
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
229 PM MST Sat Jan 3 2026

.KEY MESSAGES...

- A warm, moisture rich storm will bring valley rain and mountain
  snow tonight through Monday. The heaviest precipitation is
  anticipated late Sunday through Monday afternoon, resulting in
  travel impacts for mountain routes.

- After another relative lull, there is the potential for a colder
  system to impact the area late Wednesday into early Friday,
  bringing a high chance of snow to most valley floors, and the
  potential for significant mountain accumulations.

 &&

.SHORT TERM (Through 12Z/5AM Tuesday)...High pressure is centered
over Colorado this afternoon as a storm system moves onshore along
the Pacific coast. Utah and southwest Wyoming are under a breezy
southwest flow in between these features, with clouds and moisture
being drawn into the area in the flow. The first piece of this
splitting system is on track to move across northern Utah and
southwest Wyoming tonight, bringing valley rain with snow above
about 7,500 feet across northern Utah. Precipitation rates will
not be terribly impressive with this initial feature, though there
will be accumulating snow.

After a relative lull Sunday morning, coverage of valley rain and
mountain snow will increase again over northern Utah Sunday
afternoon as the second and stronger piece of the system
approaches. This wave is expected to slide a cold front across
northern Utah Sunday night into Monday morning, providing the best
forcing of the event as well as lowering snow levels to around
6,000 feet. As one would expect, this is the timeframe for the
most significant accumulations, with travel impacts along northern
Utah mountain routes during this time. Snow is expected to linger
into Monday afternoon before high pressure briefly returns Monday
night, bringing an end to the precipitation. Going Winter Weather
Advisory for the mountains of northern Utah covers the expected
impacts of this event well.

.LONG TERM (After 12Z/5AM Tuesday)...Modestly active weather with
mountain snow continuing through the week will end with relatively
high chances for minor valley snow accumulations behind a cold front
late in the work week. High pressure is then expected to develop
heading into next weekend.

Despite a period of weak synoptic forcing on Tuesday, expect light
orographic showers to continue with modest westerly flow. As this
mid-level zonal flow gradually becomes more anticyclonic, we may see
a bit of an uptick in these showers, particularly across northern
Utah, by early Wednesday. However, with unimpressive jet dynamics
and limited moisture only around 100-130% of normal, QPF will be
pretty minimal during this initial period. Deterministic models then
suggest an initial shortwave trough develops, moving across northern
Utah around Wednesday afternoon/evening, resulting in another modest
increase in precipitation coverage. During this period, snow levels
will be around 5000-6000ft.

Conditions will get a bit more interesting with a passing cold front
early to mid-day Thursday. Aside from a period of heavier
precipitation along the frontal passage itself, this front will
bring cold, northwesterly flow, with moisture lingering in the low
levels through at least Friday morning statewide. In fact, ensemble
guidance is in pretty good agreement of 700-mb temperatures dropping
to around -14C to -16C by Friday morning. There are a few related
impacts here: 1) areas favored in northwesterly flow, such as the
Cottonwoods, could do quite well orographically, especially given
high snow ratios. 2) Snow levels will drop to 4000ft/below most
valley floors by Thursday afternoon at the latest, resulting in a
period of valley snow. 3) The potential for lake-effect or lake-
enhancement off of the Great Salt Lake, which could locally enhance
QPF.

So, how much snow can we expect? Well, keep in mind the limited
moisture referenced earlier in this discussion, which will
ultimately limit QPF in areas without mesoscale forcing
(orographics, lake-effect, etc.), especially across southern Utah.
Still, the northern mountains still could see a fair bit of snow
between Wednesday and Friday, perhaps around 8-14" for an initial
amount (4-8" in the central/southern mountains), with locally higher
amounts in northwesterly favored areas. For example, the NBM 25th-
75th percentile spread is still fairly wide around 14-24" for the
Upper Cottonwoods...and often this area will verify above even the
75th percentile. The highest valley snow accumulations are expected
along the Wasatch Back, with a 70% chance of greater than 6 inches
of snow in Park City. Going down in elevation, east benches along
the Wasatch Front have a 50% chance of greater than 4 inches of
snow...with a 60% chance of greater than 1 inch of snow across the
lowest elevations of the Wasatch Front between Thursday afternoon
and Friday morning. Chances for snow are lower in most other valleys.

While some model guidance suggests a trailing wave on Friday which
would reinforce the cold air (30% chance), confidence is higher in
high pressure building over the west coast, bringing very dry
conditions and subsidence to Utah and southwest Wyoming next weekend.

&&

.AVIATION...KSLC...Increasing SW flow ahead of a deepening Pacific
trough will result in modestly breezy conditions, primarily during
the daytime or periods of precipitation. With increasing moisture,
precipitation chances will increase and clouds will lower overnight
into Sunday, with mountain obscuration becoming more likely.
Depending on precip strength, there is ~10-20% chance for periods of
IFR CIGS, and 30-40% chance of MVFR CIGS. Precipitation is expected
to become further widespread late Sunday into the overnight hours.

.REST OF UTAH AND SOUTHWEST WYOMING...A broad Pacific system
approaching will result in an increase to modestly gusty SW winds at
most area terminals. It will also increase moisture, in turn
resulting in more expansive (and lower level) cloud cover, as well
as elevated precipitation chances especially at northern terminals.
Snow levels at area terminals will be roughly in the 7250-8250 ft
range. Around a 30-40% chance of MVFR conds and 10-20% chance of IFR
conds noted at terminals favoring rain, precip rate depending.
Chances of deteriorated conditions increase markedly at terminals
where sufficiently cold air changes precip type to snow.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Weather Advisory from 11 PM this evening to 11 PM MST
     Monday for UTZ110>112.

WY...None.
&&

$$

SHORT TERM...Traphagan
LONG TERM...Cunningham
AVIATION...Warthen

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