809
FXUS65 KSLC 061035
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
335 AM MST Sat Dec 6 2025

.SYNOPSIS...Valley rain and heavy mountain snow over northern Utah
and southwest Wyoming will continue through midmorning, with
precipitation becoming more showery during the afternoon before
tapering off tonight. Another storm system may impact northern
Utah for the middle of the upcoming week.

&&

.SHORT TERM (Through 12Z/5AM MST Monday)...

Key Messages and Impacts:

- Heavy mountain snowfall will continue through mid-morning, with
  peak snow rates up to 2 inches per hour through this period.
  Though snowfall rates will relax for the late morning and
  afternoon, upslope showers will continue through Saturday night
  or Sunday morning.

- Snow levels in the 6,000 to 7,000 foot range will lower to
  around 5,500 feet this afternoon, though valley and mountain
  valley precipitation will be more limited during this time.

- 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 midweek.

Much of Utah and southwest Wyoming is under a moisture rich west
to northwest flow this morning. The position of the upper level
jet is allowing for sufficient instability for the development of
precipitation, primarily focused over the higher terrain of
northern Utah. This heaviest period of precipitation with the
storm system will continue into mid-morning, with the
precipitation spreading farther south into central Utah.

The jet is forecast to weaken significantly beginning mid-morning,
and the decrease in instability will allow precipitation to start
to taper off, even as a weak cold front moves in with associated
shortwave energy this afternoon, lowering snow levels just a bit,
though they will remain above valley floors. As this wave exits
the area this evening and overnight and the Pacific ridge nudges
eastward, anticipating the end of precipitation with this system.

Current suite of warnings and advisories matches the threat well
and have not made any changes to headlines.

.LONG TERM (After 12Z/5AM MST Monday)...Warmer and dry conditions will
persist across southern Utah this week while northern areas see
mildly active weather continuing through much of the long-term
period.

Through the work week, the longwave pattern is not expected to
change much, with just subtle variations of the ridge centered off
of the west coast. Moisture associated with a landfalling
atmospheric river will stream overtop this ridge and into the
Intermountain West, though there still remains plenty of uncertainty
with how much is able to reach northern UT/southwest WY. At the
lower end, expect light precipitation to continue intermittently
across northern Utah through much of the week, with the NBM 25th
percentile showing 0.00-0.20" across the northern mountains between
Tuesday morning and Thursday morning in particular.

Despite an overall lack of synoptic support, the QPF distribution
has actually increased compared to yesterday, especially on the
higher end. Currently, the 75th percentile shows 0.50-1.00" of QPF
for the northern mountains, with up to 1.50" in the Bear River Range
which is generally favored in this flow regime (and is closer to
that main moisture plume). It`s worth noting too that 700-mb winds
could be pretty high across extreme northern UT and southwest WY,
reaching an ensemble mean of 45kts by mid-week, leading to better
orographic enhancement in favored areas. Snow levels will rise to
8000-9000ft by Wednesday, resulting in denser mountain snow and
valley rain. Clearly, there is still a lot of spread, really
depending on the trajectory of this landfalling AR.

Dry conditions will expand across the forecast area by next weekend,
with even the 90th percentile QPF reaching 0" statewide as the ridge
likely builds across the western US. Temperatures will remain
relatively high through the long-term period, likely reaching 10-20
degrees above normal.

&&

.AVIATION...KSLC...Wind direction could be a bit tricky this
morning, with some question as to when winds transition from
southeasterly to northwesterly with gusts to around 20kts. The most
likely timing is by 16z, however this could occur as early as 13z. A
few more isolated rain showers will be possible through 14z, with
CIGs lifting thereafter. VFR conditions will most likely prevail,
with only a 15% chance for MVFR conditions with any heavier shower
before 14z.

REST OF UTAH AND SOUTHWEST WYOMING...A broad area of precipitation
early this morning, mainly across higher terrain, will gradually
shift southward into central Utah before diminishing by around 19z.
Strong west-northwesterly winds will continue, gradually decreasing
in magnitude heading into the late afternoon and evening hours. The
highest gusts can be expected at KEVW, with gusts up to 40kts
possible through the morning. CIGs will lift statewide, particularly
after 18z if not beforehand.

&&

.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 this afternoon for UTZ109.

WY...Winter Weather Advisory until 5 PM MST this afternoon for WYZ021.

&&

$$

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

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