112
FXUS65 KSLC 172306
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
406 PM MST Wed Dec 17 2025

.KEY MESSAGES...

- Downslope winds are expected for Castle Country this evening and
  overnight behind a frontal passage, bringing strong winds with
  gusts in excess of 60 mph to the SR-10 corridor.

- Gusty winds across northern Utah have already peaked this
  afternoon, but will remain elevated before tapering this
  evening.

- Another warm storm brings increased winds and another shot of
  rain and high elevation snow to northern Utah Friday into
  Saturday.

&&

.SHORT TERM (Through 12Z/5AM Friday)...Current radar imagery shows
showers associated with a cold front passage ongoing across
portions of northern Utah south of I-80 early this afternoon.
Showers will continue to track southeastward this afternoon before
diminishing around 5-6 PM as the upper-level jet providing
efficient moisture transport into northern Utah lifts out of the
region.

The aforementioned jet also brought us gusty winds across the
region today, with most locations across northern Utah and
southwest Wyoming having already observed their peak winds for
the day as a cold front passed through the region early this
afternoon. Given current downtrends across the area, most wind
headlines for northern Utah and southwest Wyoming will be allowed
to expire at their planned times this afternoon and evening... or
potentially earlier. A new High Wind Warning was hoisted for
Castle Country with this afternoon`s forecast, downsloping winds
off the terrain behind the cold front passage are expected to
produce winds in excess of 60 mph late tonight into early Thursday
morning. Strongest winds are expected along the SR-10 corridor
mainly between Huntington and I-70 including Fremont Junction,
with the main period of concern being between 8 PM-midnight
tonight -- there is a 30% chance for gusts to exceed 70 mph
across the area during this period. Strong winds are expected to
taper off across Castle Country early Thursday morning as they
retreat back along the terrain. Given northwesterly flow, strong
crosswinds will be a concern along SR-10. High- profile vehicles
and vehicles towing trailers should use extra caution.

Dry conditions linger areawide into early Thursday before the jet
shifts slightly south late Thursday, though greatest moisture will
remain well to our north. As such, a brief period of light rain
and high elevation snow showers are expected Thursday afternoon
for areas generally north of I-80 and east of the I-15 corridor.
Overall totals will be little to none for most areas, with highest
accumulations across the Bear River Range with upwards of 0.2
inches of QPF and 2-3 inches of snow.

.LONG TERM (After 12Z/5AM Friday), Issued 312 AM MST...
There will be largely dry
conditions throughout southwest Wyoming and Utah to start Friday,
excluding far northern Utah, where there will remain sufficient
moisture and forcing as the atmospheric river (AR) event from
Thursday lifts north. Snow levels will be around 7000 feet, with
minimal accumulation. There will be another surge of wind,
especially for southwest Wyoming and northern Utah, ahead of
another AR event. Winds will be from the west to southwest,
associated with warm air advection and valley high temperatures in
the 50s to low 60s, around 20F warmer than normal.

The AR event that will track into the PacNW Thursday will slide
south through Friday. That will bring moisture advection and
forcing associated with a jet streak in already impressive
westerly flow. Precipitation probability will increase from north
to south through Friday afternoon, with valley rain and mountain
snow for southwest Wyoming and much of northern Utah Friday night
through Saturday. Snow levels through late Friday will be around
7000 feet near the Idaho border and 7500 feet for the Cottonwoods.
Despite strong forcing, there won`t be strong cold air advection
as the baroclinic zone pushes through into Saturday because of the
warmer source of the AR. Snow levels will lower to around 5500
feet near the Idaho border and 7000 feet for the Cottonwoods as
precipitation tapers significantly later Saturday. Water content
will range from 0.75- 1.50" for the Bear River Range and from
0.50-1.00" for the Uintas and Cottonwoods. Snow ratios will range
from 5-10:1 most of the event. Snow accumulation will be
influenced by how far north and the elevation of a location, with
the most accumulation around ridgelines in far northern Utah.
Nearby valleys, including the urban corridor of northern Utah,
will have rainfall ranging from 0.10- 0.50". Weak cold air
advection will lower valley high temperatures Saturday to around
50F for northern Utah.

Another surge of AR moisture will track into the western U.S. for
the end of the weekend. The main difference will be that this
will have a more southern track, which will bring downslope flow
from the Sierra Nevada Mountains. The track would result in the
majority of precipitation north of Utah.

&&

.AVIATION...KSLC...VFR conditions are expected through the TAF
period. Gusty post-frontal northerly winds will persist into early
evening, delaying the diurnal swap to southeast until 07-08z. Cigs
should lift above 6kft agl around 03z.

REST OF UTAH AND SOUTHWEST WYOMING...Northern airport terminals can
expect gusty post-frontal northerly winds into mid-evening,
persisting into early morning for EVW. Southern terminals will have
typical diurnal light winds and clear skies.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...High Wind Warning until 5 PM MST this afternoon for UTZ101-102-
     105-106.

     Wind Advisory until 5 PM MST this afternoon for UTZ103-104-107-
     109-110.

     Wind Advisory until 11 PM MST this evening for UTZ114.

     High Wind Warning until 2 AM MST Thursday for UTZ120.

WY...High Wind Warning until 8 PM MST this evening for WYZ021.

&&

$$

SHORT TERM...Whitlam
LONG TERM...Wilson
AVIATION...Verzella

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