490
FXUS65 KSLC 180459
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
1059 PM MDT Sun May 17 2026

.KEY MESSAGES...

- A quite unseasonably cold storm system will result in
  temperatures 10-20F below normal by Monday along with
  accumulating mountain and mountain valley snow Sunday night into
  Monday, significant for the Western Uinta mountains and in
  southwest Wyoming.

- Freeze conditions will impact many Utah valleys outside of the
  Wasatch Front Monday and Tuesday mornings. Areas that will see
  the greatest impacts include west central Utah, southwest Utah,
  Cache Valley, the western Uinta Basin, and the Sanpete and
  Sevier valleys.


&&

.DISCUSSION...Cyclogenesis is ongoing across the Utah as a trough
pushes an unseasonably cold airmass through the area while tapping
into spring moisture. This is creating a large swath of
precipitation stretching from the southwest corner of Utah up
through Uinta county Wyoming. As the low ejects to the northeast
precipitation will end from southwest to northeast between sunrise
and noon tomorrow. Freezing temperatures are expected for some
valleys tonight and again tomorrow night. Mean troughing will
remain overhead through the end of the week with another chance of
precip across the north with a shortwave on Thursday. A drying and
warming trend will continue late week into the weekend.

Currently, snow levels have fallen as low as 5500 feet across
southwest Utah. Areas from Cedar City up through Cove Fort could
see accumulating snow, primarily on non-paved surfaces. However,
given the overnight nature and any higher intensity rates there
could be brief slush ups on area roads through the morning hours.
Precipitation should be wrapping up by sunrise across areas of
southwest Utah. The area of greatest impacts for accumulating snow
will be across Uinta County, Wyoming and the western Uintas where
snow is currently falling with temperatures at or below freezing.
Snow totals in these areas will range from 2 to 6 inches across
the lower elevations near Evanston to over a foot possible along
the north slopes of the Uintas as northerly flow enhances snowfall
rates overnight. Portions of the high Uintas could see as much as
2 feet of snow.

For northern Utah, light rain is slowly filling into the area and
will continue overnight before tapering off tomorrow morning. QPF
totals will likely only amount to a few tenths of an inch as we
sit along a west to east moisture gradient with the highest QPF
totals across the terrain to the east of the Wasatch Front. This
will translate to 6 to 12 inches of heavy wet snow across the high
terrain of the mountains stretching from southern Utah up through
the Wasatch mountains. Lesser amounts are expected up in the Bear
Rivers where totals are close to 2 to 4 inches.

Freezing temperatures are expected tonight across southwest
Utah/central valleys and the Wasatch Back, but cloud cover and
moisture will keep these temperatures from dipping too far below
freezing. As skies begin to clear tomorrow expect even colder
temperatures tomorrow night with additional locations such as
Cache Valley and the western Uinta Basin getting in on the
freezing temperatures.


&&

.AVIATION...KSLC...Periods of rain are expected to continue through
much of the night before tapering off after 13z Monday morning.
Conditions are expected to largely remain low-end VFR in the rain,
except for a 40% chance of periods of MVFR during heavier
precipitation mainly between 09-11z. Winds will be light northerly
or variable (owing to precipitation) through around 08z before the
gradient tightens to support stronger northerlies again, with will
continue through Monday afternoon.

.REST OF UTAH AND SOUTHWEST WYOMING...Fairly widespread
precipitation is expected to continue across much of southern and
central Utah into Monday morning, and across northeast Utah and
southwest Wyoming through at least Monday afternoon. Snow levels
will likely fall to between 5-6kft MSL, lowest late tonight through
Monday morning. Terminals located above the snow level will likely
see IFR/MVFR conditions in snow, while those below the snow level
will see largely VFR conditions with periodic MVFR in areas of
heavier rain. Otherwise, winds will be largely northerly for much
of the area to northeasterly across southwest Wyoming and northeast
Utah.

&&

.FIRE WEATHER...Widespread precipitation across the area in the
form of snow down to 5000 feet and rain at lower elevations will
continue overnight with elevated relative humidities. Northerly
and northwesterly winds will remain elevated through much of the
day tomorrow before gradually decreasing. RH will remain well
above 15% for the entire area through the day before gradually
drying throughout the week.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Freeze Warning until 9 AM MDT Monday for UTZ108-115-116-118-119-
     122.

     Freeze Warning from midnight Monday night to 9 AM MDT Tuesday
     for UTZ108-114>116-118-119-122.

     Winter Weather Advisory until midnight MDT Monday night for
     UTZ112.

WY...Winter Weather Advisory until midnight MDT Monday night for
     WYZ021.

&&

$$

PUBLIC...Mahan
AVIATION...Cheng
FIRE WEATHER...Mahan

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