576
FXUS65 KSLC 051100
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
400 AM MST Fri Dec 5 2025

.SYNOPSIS...A significant winter storm will impact northern and
central Utah through Sunday morning. The potential for unsettled
weather continues through the middle of the upcoming week.

&&

.SHORT TERM (Through 12Z/5AM Sunday)...

Key Messages:

- The northern and central Utah mountains will see periods of snow
  through late Saturday or early Sunday, with the heaviest period
  of snowfall expected Friday night into Saturday morning. Storm
  total snow accumulations are expected to range from 1 to 3 feet
  of heavy, wet snow.

- Valley snow will be dependent on elevation and cold pool
  strength. Accumulations will most likely range from 1-2 inches
  in the Cache Valley and eastern Box Elder County, 3-8 inches in
  the Ogden Valley, 8-16 inches in Park City area, trace to 1
  inch in the Salt Lake Valley, 1-3 inches near Ogden, and 1-3
  inches in the Heber Valley. There is still a 25% chance that
  snow totals exceed these amounts.

- An unsettled pattern will continue for northern Utah through at
  least the middle of the upcoming week, though accumulations will
  be on the light side.

Utah and southwest Wyoming are under a northwest flow this morning
on the front side of a broad ridge centered off the Pacific coast.
Seeing atmospheric river moisture descending from the top of the
ridge over the Pacific Northwest and spreading into northern
portions of the forecast area at this time. Associated snowfall,
generally light at this time, has developed over approximately the
northwest quarter of Utah, and is forecast to spread south across
the northern half of the area during the morning. Temperatures
will be gradually warming, so snow levels, currently below 4,000
feet, are expected to rise to around 6,000 feet by this evening.
Therefore, valley precipitation will transition to snow during the
afternoon hours, though this may be slower to occur in areas where
cold pools develop like the Cache Valley.

A relatively lull in snow is expected during the afternoon into
the early evening before more favorable jet support arrives,
bringing the heaviest period of precipitation of the event tonight
into Saturday morning. Given the moisture rich airmass, warming
temperatures, and the duration of the event, the mountains of
northern and central Utah will see significant accumulation of
heavy, dense snow, primarily in the 1 to 3 foot range, with the
highest amounts in areas that do well in northwest flow like the
Cottonwoods and the Bear River range. This will bring notable
travel impacts. High mountain valleys, such as the Park City
area, will see significant snow as well, but totals for lower
elevations will be suppressed by the increasing snow levels.

As the associated shortwave energy crosses the area during the day
Saturday, a frontal boundary will switch the precipitation from a
warm advection regime to a cold advection one, though snow levels
will remain relatively high. Most associated precipitation will
end Saturday night, with some mountain showers lingering into
Sunday.

.LONG TERM (After 12Z/5AM Sunday)...The longwave pattern will remain
largely unchanged through the long-term period, resulting in only
minor sensible weather changes through the week across the forecast
area. With high pressure centered well off the California coast,
Utah and southwest Wyoming will likely see persistent anti-cyclonic,
west-northwest flow on the eastern periphery of the ridge. Weak warm-
air advection will produce both increasing temperatures and snow
levels, with highs reaching 10-15 degrees above normal statewide as
early as Tuesday. It`s looking to be a beautiful week across
southern Utah, with highs increasing to the upper-50s to mid-60s
with minimal cloud cover. Sorry, snow lovers.

Lingering moisture will still be in place across the north,
resulting in continued chances for light precipitation through the
week. Snow levels will slowly rise from around 4000-5000ft on Sunday
morning to above 7500ft by Wednesday. Precipitation amounts,
however, still depend on the positioning and strength of the
aforementioned ridge. We can divide this into roughly two main
scenarios: first, if the ridge is more amplified and/or slightly
further inland, this would divert moisture associated with a
landfalling atmospheric river well to our north. The second, less
probable solution favors more zonal flow which could produce more
precipitation and stronger winds across northern UT/southwest
WY...though chances for this occurring are decreasing, with chances
for more substantive precipitation now less than 10 percent. While
model trends do point more towards these drier solutions, this isn`t
to say that the area will remain fully dry...just that both PoPs and
QPF will remain low through the week.

For Friday and beyond, most model guidance suggests high pressure
will build across the western US, though around 25% of ensemble
members do favor a more active longwave pattern. Forecast confidence
remains fairly low at this time.

&&

.AVIATION...KSLC...A second round of precipitation will move into
the area early this morning, resulting in a period of light-moderate
precipitation between ~14-19z (though intermittent showers may
continue through the afternoon). MVFR conditions will accompany this
round, with a 30% chance for periodic IFR conditions. Snow will
transition to rain in the early afternoon, and will remain rain as a
second round of heavier precipitation moves in Friday night. CIGs
are expected to remain below 5000ft through the TAF period.

REST OF UTAH AND SOUTHWEST WYOMING...Snowfall will continue across N-
UT/SW-WY this morning, resulting in periodic MVFR-IFR conditions.
Showers will become more scattered and showery in nature this
afternoon, with many valley sites transitioning to rain as snow
levels rise above 6000ft. Gusty westerly winds will develop mainly
across higher terrain and over SW-WY, with gusts increasing to
around 30kts at KEVW by Friday evening.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Weather Advisory until 11 AM MST this morning for UTZ103-
     107.

     Winter Storm Warning until 5 AM MST Sunday for UTZ108-110>113-
     117.

     Winter Weather Advisory from 5 PM this afternoon to 5 PM MST
     Saturday for UTZ109.

WY...Winter Weather Advisory from 5 PM this afternoon to 5 PM MST
     Saturday for WYZ021.

&&

$$

SHORT TERM...Traphagan
LONG TERM/AVIATION...Cunningham

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