This is an archived article that was published on sltrib.com in 2017, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

A major winter storm proved both a curse and blessing for Utah, snarling Thursday morning's commute in deadly ice and snow, even as freezing temperatures slowed floodwaters along the northern Wasatch Front.

Beginning with a fiery and fatal collision of two semi-trailer rigs on Interstate 80 in Parleys Canyon just before midnight Wednesday — and another semi-car fatal crash Thursday morning on southbound I-15, 7 miles south of Brigham City — Utah Highway Patrol troopers scrambled from one weather-related accident scene to another.

Westbound I-80 was closed near Jeremy's Ranch well into the morning commute. Troopers diverted traffic onto Highways 40 and 84 while clearing the scene of semis' wreckage, causing the usually heavy flow of traffic into the Salt Lake Valley to become a bumper-to-bumper mess in places.

By 8:30 a.m., troopers had responded to more than 50 storm-related crashes in Salt Lake, Weber and Utah counties alone. Another half-dozen crashes kept Salt Lake Valley public safety dispatchers busy.

A Winter Weather Advisory remained in place for the Wasatch Front, western Uintas, Wasatch Plateau, Book Cliffs and the central Utah mountains through 4 a.m. Friday. However, the storm was to taper off late Thursday and early Friday morning, having dumped anywhere from 10 to 38 inches of new snow in the mountains.

Daytime temperatures, which had flirted with 60 degrees earlier this week, tumbled into the low- to mid-30s on Thursday. Friday's highs were to be a few degrees colder. Along with forecasts for overnight lows in the upper-teens, that was good news for Box Elder, Cache and Weber counties.

Unseasonably warm temperatures in those counties last weekend lead to mudslides and residential flooding that brought hundreds of volunteers out to fill and place sandbags. Box Elder County was especially hard-hit, with an estimated 80 Tremonton-area homeowners reporting yard and basement flooding from snow melt accelerated by rain showers.

On Wednesday, a dozen Utah National Guard troops pitched in to help fill sandbags at the Box Elder County Fairgrounds.

Lt. Gov. Spencer Cox also toured the affected area, apparently on a fact-finding mission related to the county's plans to seek state and federal aid to offset more than $3 million in flood-related expenses.

While northern Utahns slid on icy mountain roads and filled sandbags in their sodden valleys, their southern Utah counterparts enjoyed clear, sunny skies and highs in the low-50s Thursday. An encore of that forecast was predicted for Friday.

The Utah Avalanche Center warned of "considerable" risk for potentially deadly mountain backcountry snowslides in the Logan, Salt Lake, Provo and Uintas districts. The mountains above Ogden and Moab, along with the Abajo Range, were at "moderate" risk, and the Skyline district was rated as "low."

The Utah Division of Air Quality once more awarded "green," or healthy grades for all the state's monitoring stations through Friday.

For more extensive forecast information visit the Tribune's weather page at http://www.sltrib.com/news/weather/.

Twitter: @remims