textproduct: Salt Lake City

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.

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.