Area Forecast Discussion
Issued by NWS Salt Lake City, UT

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13
706
FXUS65 KSLC 022228
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
328 PM MST Tue Dec 2 2025

.SYNOPSIS...An active pattern will continue across the region
through the weekend. An upper level low will bring the threat of
snow to most locations tonight into Wednesday morning across
northern and central Utah. After a break, another storm system
will impact portions of northern and central Utah Friday into the
weekend.

&&

.DISCUSSION...An active pattern will continue to impact the region
through at least this weekend. Early afternoon upper air and
satellite analysis indicates deep northerly flow from Alaska into
the Intermountain Region. An upper level low embedded in this flow
is near Boise this afternoon and will shift south through the
overnight hours.

Showers continue across northern Utah, though dewpoint depressions
are such that most precipitation is evaporating prior to reaching
the ground.

Two main scenarios can be expected across northern Utah this
evening into the overnight hours. The first and most likely
scenario (85% chance) is periodic snow showers will continue
across northern and central Utah as the upper level low shifts
southward through 09-12Z Wednesday. Given the showery nature of
the precipitation, the most likely valley snow total range will
be trace to 2 inches, up to 3 inches on benches especially for
Tooele County.

Scenario 2, while unlikely (15% chance), would be more impactful.
In this scenario, forcing with the upper level low will combine
with northerly flow over the Great Salt Lake to bring a period of
moderate to heavy snow to eastern Tooele County and northwestern
Salt Lake County...beginning around 6-8 PM and continuing through
3-5 AM. This scenario would bring heavier snow accumulations,
around 4 to as much as 8 inches for the eastern Tooele Valley,
Magna and the remainder of western Utah through about Taylorsville
to West Jordan.

For now, confidence in the higher impact scenario is below the
threshold for any type of winter weather advisory, but those who
have overnight travel and/or an early morning commute in the
Tooele and western Salt Lake Valley areas should be prepared for
the potential for winter driving conditions.

In the wake of the upper level low, shortwave ridging will build
across the area. As a strong jet max shifts around the northern
side of a robust eastern Pacific ridge, synoptic scale forcing
combined with mid-level warm air advection will shift into
northern Utah late Thursday into early Friday. Precipitation will
initially begin as snow across the northern valleys, but gradually
increasing snow levels will slowly change any snow to all rain for
most valley locations Friday afternoon into Friday evening. The
heaviest precipitation with the first round is expected Friday
evening into Saturday morning associated with the left exit region
of the jet max. Another period of deeper forcing Saturday evening
into Sunday will bring the potential for another round of
precipitation. Current 25th to 75th percentile snow accumulations
for the northern mountains range from 8 to 18 inches with locally
up to 2 feet in the upper Cottonwoods. Valley snow totals would
range from around trace to 2 inches valley floors, up to 4 inches
benches...most of which would fall early in the event.

Looking at the last four runs of the major ensemble systems,
around 30% of the ensemble members represent an alternate scenario
to the above description, with the best jet support remaining
north and east of the region. This subset, while 15% of the
members in earlier runs has an increased following with the 12Z
runs (up to 30%). Whether this is represents an increasingly
significant shift in the guidance remains to be seen...but total
accumulations would be roughly 50% of the current forecast in this
scenario (roughly 4 to 8 inches for the northern mountains).

The vast majority of ensemble members build the eastern Pacific
ridge eastward next week. Whether this is a dry pattern, or
whether shortwave troughs embedded in northwesterly flow shift
occasional cold fronts with associated precipitation across
northern Utah will be the main question. Confidence is much
higher that central and southern Utah will shift into a dry, more
typical La Nina pattern.

&&

.AVIATION...KSLC...CIGs are expected to drop and remain below
6000 feet around 23-00z as a cold storm brings snow showers to the
terminal. Reductions to MVFR and brief IFR conditions are
possible in the evening and overnight as a period of heavier
precipitation is expected to accompany a frontal passage. Winds
remain overall light through the TAF period, with a period of
variability as showers approach the terminal, switching northerly
by 00z and remaining north behind the frontal passage overnight
and into tomorrow.

.REST OF UTAH AND SOUTHWEST WYOMING...Lowered CIGs will persist
into the evening ahead of a cold front spreading through the
forecast area. Snow showers associated with this storm are
expected to move into northern Utah and southwest Wyoming around
23z this afternoon, gradually moving southward through the
remainder of the evening. These showers may bring periodic
MVFR/IFR conditions to northern Utah terminals through early
Wednesday morning. Winds will remain light through the day except
for lingering gusts at EVW, until a cold front moving through the
region this evening and overnight brings increased northerly winds
into Wednesday.

&&

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

$$

Kruse/Verzella

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