538
FXUS65 KSLC 032251
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
351 PM MST Wed Dec 3 2025

.SYNOPSIS...A significant winter storm will impact northern and
central Utah late Thursday into Sunday morning.

&&

.DISCUSSION...One of the bigger winter storms of the fall season
looks to be loading up for the northern mountains Friday into the
weekend. Early afternoon upper air and satellite analysis
indicates an upper level low is shifting across the 4 Corners
area. A strong eastern Pacific ridge remains displaced offshore. A
strong jet max is rotating around the top of this ridge.

Aside from some light snow showers across mainly southern Utah and
patchy fog across northern Utah, the next 24 to 36 hours will be
relatively quiet, cold and dry.

A strong jet max will round the northeast side of the ridge and
shift into the Interior West Thursday. This, combined with modest
warm air advection will support the development of precipitation
across northern Utah after midnight Thursday night. With a cold
airmass in place, initial precipitation will be all snow to valley
floors. As warm air advection continues, snow levels will
gradually rise to around 5500 feet by Friday night, 6000 feet by
Saturday morning. At least one round of moderate to heavy
precipitation is likely, from Friday afternoon through Saturday
morning.

There is a small subset of ensemble members that support a more
north and east jet position, which would result in a less
prolific storm across much of northern Utah. This subset continues
to shrink however and didn`t represent enough of the ensemble
members to cluster around this solution. While very unlikely, this
scenario will need to be monitored as storm totals would be
significantly less.

Periods of northern mountain snow and northern valley rain/snow
will continue through Saturday, gradually ending later Saturday
into Sunday. There is a subset of ensemble members that end
precipitation by Saturday evening. While, this would also
decrease storm totals, though at this time, amounts would likely
remain in the warning range for the mountains.

Looking at potential storm totals, the 25th to 75th percentile
storm totals for the Wasatch Mountains are 1 to 2 feet, with
locally up to 30 inches for the upper Cottonwoods, Ogden area
mountains and Bear River Range (all areas that do well in this
type of moist northwest to west flow). For the western Uinta
Mountains, storm totals (25th to 75th percentile) are lower but
still sizable, 8 to 18 inches.

As far as valley snow, while most valley locations across northern
Utah and Uinta County, WY will start as snow, valley floors north
of Ogden will shift to rain sometime after 2 PM Friday. This will
limit accumulations to around 2 inches or less. For the benches,
expect 2 to 5 inches. The heaviest valley snow is likely in the
Cache Valley, where a combination of cold antecedent temperatures
and colder mid-level temperatures will hold snow into the evening
and potentially overnight hours, especially for the benches.

For the Wasatch Back, which has a wider range of elevations,
expect 6 to 12 inches of snow for higher elevation areas such as
Park City and the Eden/Liberty area, with less in lower elevation
areas such as Heber and Huntsville.

Given the confidence in winter storm warning amounts of the
northern mountains and Wasatch Back is greater than 70%, issued a
winter storm watch for these areas from 09Z Friday to 12Z Sunday.
Advisories are likely going to be needed for the Cache Valley,
Uinta County, WY and the Bear River Valley/Bear Lake area...but
will see the trends in the snow levels (and how quickly a
changeover to rain will occur for the Cache). Expect winter
driving conditions on all area mountain routes across northern and
into central Utah late Thursday night into Sunday...and monitor
the forecast for potential impacts to valley routes.

In the further extended portions of the forecast, guidance
continues to vary on whether northwest flow remains well
entrenched across the region...bringing several weak disturbances
through northern Utah next week...or a significant block ridge
builds into the Interior West.

&&

.AVIATION...KSLC...Near-MVFR cigs should be lifting after 00z but
may flirt with the 6kft agl mark into tomorrow morning, with the
next round of midlevel clouds arriving around 12z. Northerly winds
will persist after the typical diurnal shift, likely
transitioning to the southeast between 05-06z.

.REST OF UTAH AND SOUTHWEST WYOMING...Cigs have lifted above MVFR
at northern Utah and southwest Wyoming terminals but may return
through the night ahead of the next round of midlevel clouds
around 12z tomorrow. That said, there exists a 30% percent chance
of fog developing at EVW and LGU after 12z. For southern Utah
terminals, CDC vicinity snow showers are expected to decrease this
evening, though residual cigs just above MVFR may persist into
late morning, while SGU should remain clear. Northerly winds will
persist for most regional terminals into late evening, delaying
any typical diurnal shifts.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Storm Watch from late Thursday night through late
     Saturday night for UTZ108-110>112.

WY...None.
&&

$$

Kruse/Verzella

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http://weather.gov/saltlakecity