937
FXUS65 KSLC 052310
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
410 PM MST Fri Dec 5 2025

.SYNOPSIS...A more noteworthy surge of moisture and atmospheric
support for precipitation will track through the northern CWA
overnight into Saturday, bringing a period that will favor heavy
mountain snow through Saturday morning. Forcing wanes by late
Saturday morning, with upslope snow continuing through early
Sunday. Potential for unsettled weather continues into the middle
of next week, though likelihood of another significant system is
fleeting.

&&

.DISCUSSION...Our winter storm continues through the next 24-36
hours, with the period of heaviest snowfall expected in the
northern and central mountains expected Friday evening through
Saturday morning.

Key Messages and Impacts:

- Heavy mountain snowfall is expected across the northern and
  central Utah mountains from this afternoon through Saturday
  morning, with peak snow rates exceeding 1-2 inches per hour
  through this period. Snowfall rates relax by mid-morning
  Saturday, however, upslope showers will continue through Sunday
  morning.

- A majority of valley areas will see a transition of predominant
  precipitation type to rain as warm advection spreads over the
  region and raises snow levels above 6,500-7,000ft.

- High pressure noses back into the region following the storm
  system, with temperatures warming back to near to above-normal
  levels. That said, moisture will attempt to sag into northern
  Utah, bringing potential for mountain snow.

As of 3:20PM, the second surge of moisture is already noted across
northern Utah, allowing for mountain snow and valley rain to
continue after the brief dry period experienced through the day.
Though little precipitation was seen through the late morning to
early afternoon hours, overhead warm advection was quietly
spreading across the region and allowed valley areas to warm
sufficiently such that rain will become the dominant
precipitation type as the moisture spreads back over the region.
Based on UDOT cameras, this thought seems to be verifying for the
lower elevation valleys. The exception to this will be in the Park
City area where snowfall will be favored throughout a majority of
the overnight moisture push. That said, as moisture begins
peaking so will the overhead temperatures. Currently, NBM mean
snow levels rise to upwards of 7,000-7,200ft during the early
morning hours on Saturday which would allow for rain to become the
prevailing precipitation type in the Park City area. With
precipitation rate driven cooling, would anticipate snow levels
max out around 6,800ft, giving the high elevation valleys of the
Wasatch Back an opportunity to remain entirely snow. Bottom line,
for this high elevation region of the Wasatch Back, anticipate
a rain/ snow mix by the early morning hours.

In the mountainous terrain, this moisture surge and more ample
upper dynamic support is likely to provide northern and central
Utah mountains with a period of heavy snowfall with peak snow
rates exceeding 1 to 2 inches per hour (greater than 0.15 to 0.2
inches SWE per hour). These snow rates are expected to be
maintained through much of the overnight hours while the best
dynamics move through the region, allowing a majority of the storm
total snowfall to occur. As mentioned above, snow levels will rise
gradually through the overnight which means that the warmer
airmass will also help to favor low snow ratios. Wet, heavy snow
will be the result in the mountains and will likely reduce overall
snowfall observations due to compaction of the snowpack.
Regardless, by the end of the peak moisture surge, anticipate a
total of 1 to 2 feet of snowfall alongside upwards of 2 to 2.5
inches of SWE in the high terrain. Snowfall amounts in the
mountains are expected to decrease notably south of the I-70
corridor with little impacts expected.

Colder air filters into the region through Saturday morning
following the peak moisture surge, allowing for high elevation
snow ratios to increase again. With moist northwesterly flow
remaining in place over the region on Saturday, would anticipate
upslope snow showers to continue while valley areas will tend to
be shadowed by upstream terrain. If we`re going to overperform
with snowfall amounts during this storm, this will be the period
to do such. Upslope snowfall is expected to continue into Sunday
morning for the northern Utah mountains, with light snow showers
potentially bleeding over into adjacent valley areas... though
impacts will be quite limited.

Through the remainder of Sunday and area of high pressure will
nose back into Utah and help to stabilize conditions. A moisture
stream will continue to be aimed at the PacNW region during this
period, allowing shortwave energy to attempt to break down the
northern periphery of the ridge/ surface high pressure. As such,
northern Utah mountains will maintain low probability (20-30%
chance) for light snow showers continuing Sunday and Monday. There
is generally high confidence that this area of high pressure will
maintain dominance through the upcoming week with the caveat of
the potential for shortwave energy to erode the northern periphery
of the ridge. Though NBM guidance shows upwards of a 40-60%
chance of precipitation in the northern mountains on Wednesday/
Thursday, ensemble cluster analysis supports only about 20-25% of
solutions with a less amplified ridge on the eastern periphery
(favoring a deeper/ stronger storm system). Biggest takeaway here
is that light precipitation may become favored in the northern
Utah mountains, but there is little support for another
significant storm system through the next week.

&&

.AVIATION...KSLC...Brief VFR conditions will transition to MVFR with
intermittent IFR conditions this evening and overnight for the KSLC
terminal. CIGs will lower this evening <3k feet as moisture
increases and rain moves into the terminal with snow levels
remaining 1-2k feet AGL. Expect mountain obscuration to persist.
Conditions begin drying early Saturday morning. Winds will remain
light and primarily out of the south.

.REST OF UTAH AND SOUTHWEST WYOMING...The northern airspace will
remain primarily in MVFR/IFR conditions as moisture pushes in this
afternoon/evening with valley rain and mountain snow along with
mountain obscuration. Snow levels will gradually rise from 5k feet
to 7k feet through the evening. Winds will be light and variable
across most terminals with stronger winds developing overnight
across the far northeastern airspace. Southern airspace will remain
dry with VFR conditions prevailing.

&&

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Storm Warning until 5 AM MST Sunday for UTZ108-110>113-
     117.

     Winter Weather Advisory until 5 PM MST Saturday for UTZ109.

WY...Winter Weather Advisory until 5 PM MST Saturday for WYZ021.

&&

$$

PUBLIC...
AVIATION...

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