New Year's Eve will bring a breather from the snow in northern Utah and -- with a little luck -- from the pollution that has plagued the valleys since Christmas.
But the snow could return as early as tonight, said National Weather Service forecaster Mike Conger.
"A little surge of moisture is coming off the Pacific later Thursday, Friday," he said, noting that an unsettled pattern will continue through midweek next week. "It might finally clear off all the gunk in the air."
The Utah Highway Patrol reported 139 vehicle accidents in Utah and Salt Lake counties through Wednesday's evening commute and multiple slide-offs. Sixteen accidents resulted in injuries.
In Beaver, a collision on a wet Interstate 15 ramp left two people dead. Kevin Willden, of Kevin's Conoco in Beaver, said the snow fell slow and steady from morning to night and plow drivers told him they had scraped 20 inches from mountain roads east of the southwestern Utah town. But the highway ramp was clear at the time of the wreck. "The roads out here are just wet."
Snow accumulated in much of northern Utah. Alta reported 16 inches, Solitude 10, Park City 8 and Snowbasin 10 between Tuesday and Wednesday.
With the powder piling up, the Utah Avalanche Center issued an advisory warning of increased danger, thanks to the snowfall, winds and a "very fragile and weak" base.
The northern Utah mountains near Logan have a "high" avalanche rating, while slopes in the Wasatch and Uintas were rated "considerable" -- meaning that both natural and human-triggered slides are likely -- for steep western-, northern- and eastern-facing slopes at all elevations.
In Salt Lake City, forecasters predicted highs for the next few days in the mid-30s and lows in the 20s -- warmer than the frigid temperatures that, as of Tuesday, put this December's average at 6.7 degrees below normal.
Rain and snow are expected Friday and Saturday.
In St. George, highs will creep above 50 during the next few days. Lows will be in the 30s. Skies will be partly cloudy, except for Saturday, when the forecast is for sun.
Utah's air-monitoring office kept the "red," or unhealthy, alert posted through tonight. Even a day's worth of snowfall beginning Tuesday was not enough to scrub out wintertime pollution that had built up under an inversion.
"We still have that [high-pressure] cap over us," said Ken Symons, of the air-monitoring office. "It's been nuisance snow that just came right through the inversion, which happens sometimes."
But forecasters are not expecting improving air quality until later in the day, when temperatures begin to warm.
Tribune reporters Lindsay Whitehurst and Bob Mims contributed to this report.
For the latest conditions, check the Utah Avalanche Center Web site at utahavalanchecenter.org/