Sterling, Utah Weather Forecast Discussion

388
FXUS65 KSLC 222140
AFDSLC
Area Forecast Discussion
National Weather Service Salt Lake City UT
340 PM MDT Mon Sep 22 2025
.SYNOPSIS...Following todays unsettled pattern, benign conditions
develop as ridging persists through the next few days. Chances for
rain return across at least southern UT as early as Thursday.
&&
.DISCUSSION...
Key Messages:
* Scattered showers and thunderstorms persist over eastern UT and
  southwest WY this afternoon before a drier pattern takes hold
  through at least midweek.
* For snow lovers, some snowfall has been observed across the high
  Uintas this afternoon and is expected to persist through the
  evening.
* Minimally impactful canyon winds appear possible tomorrow morning
  for Washington, Davis, and Weber county canyons. Another chance
  for morning canyon winds across the aforementioned areas exists
  Wednesday morning.
* Below normal temperatures are forecast tomorrow across the
  forecast area before temperatures rebound to near-normal Wednesday
  through the weekend.
* Chances for rain return for southern UT on Friday as moisture
  advects north into UT.
Currently, showers and thunderstorms are ongoing across the high
terrain of central UT and the Uinta basin with lingering moisture
sparking isolated showers across northern UT and SW WY. Following
this activity, an omega block is forecast to develop over the
western U.S. as troughing prevails over the eastern U.S., a ridge
develops over much of the interior western U.S., and a cutoff low
meanders off the south-central CA coastline. This is expected to
bring dry and benign conditions to the forecast area through at
least Wednesday. Temperatures tomorrow will remain slightly below
normal before heights increase on Wednesday which will serve to
raise temperatures across the forecast area to near normal through
the weekend. Canyon winds across northern UT, particularly canyons
across Davis and Weber county, may see canyon winds early tomorrow
morning and Wednesday morning as easterly winds develop over the
Wasatch. Additionally, northeasterly winds will develop across
Washington county tomorrow morning, and perhaps Wednesday morning,
resulting in canyon winds as well.
Come Thursday, enhanced flow within the northern stream will begin
to erode the northern edge of the aforementioned ridge. This will
serve to weaken the ridge with a slight eastward movement as it
attempts to phase into the mean flow to the north. As a result, the
aforementioned cutoff low will begin to slide east across southern
CA into western AZ/southern NV with UT sitting along its
northeastern periphery. As a result, south-southeasterly winds will
translate to the surface and overspread the area. This is where the
forecast begins to diverge somewhat as more moving parts are added.
Ensemble guidance still remains foggy on the exact positioning of
the low to our southwest, where we would want the low further east
for the best chances of rain across southern UT and perhaps the
northern half of the forecast area. Second, tropical storm Narda
will be churning southwest of southern CA which could incorporate
more moisture into this setup depending on the position of Narda in
a few days.
Omega blocks typically yield some uncertainty with forecasting in
the extended, and adding a tropical system to the forecast doesn`t
make the waters any less muddy. Cluster analysis has began to come
closer to agreement within the ensemble suites with ~70% of all
ensembles (GFS, EURO, Canadian) with the low situated somewhere
along far southern NV to southwest CA which would put us in a
favorable pattern for rainfall across southern UT. Although, 30% of
ensembles push the low off to the east much faster which would
likely inhibit the amount of moisture that is advected north into
the CWA. While confidence has increased somewhat, there are still
some caveats that need ironed out. Regardless, a pattern shift for
at least southern UT appears on tap as we approach the end of the
work week.
&&
.AVIATION...KSLC...VFR conditions will persist for the KSLC terminal
tonight and tomorrow. There is a very low chance (less than 20%) for
vicinity showers this afternoon, otherwise clearing skies are
expected this evening and persisting through tomorrow. Light
northwest winds will persist through the evening and into the
overnight hours, with a low chance (20-40%) of persisting all
through the night. Otherwise, expect light southeast winds to
develop overnight.
.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will persist
for the airspace through the period in the wake of a passing front
(currently stretching from KPUC to K74V and quickly moving
eastward). Areas ahead of and along the front will see scattered
showers with isolated MVFR cigs/vsbys in heavier precipitation.
Behind the front, a few cumulus and isolated showers will die off
after sunset, allowing for calm and clear conditions overnight.
&&
.FIRE WEATHER...Storms are ongoing across the high terrain of
central UT and the Uinta Basin which are expected to clear the area
this evening. Following this, high pressure builds into the area
which will result in a dry pattern across UT through at least
Wednesday. Tomorrows temperatures will start below normal before we
see a gradual warm up to near normal temperatures by midweek. On
Thursday, there is a signal for a pattern change as low pressure
moves by to our south which could push moisture up into UT once
again raising humidities and increasing chances for rain. There is
some uncertainty surrounding this regarding the track of the low,
but there is good agreement that precipitation appears possible
across southern UT starting Thursday through the weekend.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&
$$
PUBLIC...Worster
AVIATION...VanCleave
FIRE WEATHER...Worster
For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity

NWS SLC Office Area Forecast Discussion