Utah forecast: A cold and stinky weekend ahead

Air quality Friday was worsening as a high pressure system trapped increasing amounts of cold air laden with automobile, industrial and other pollutants in Utah's urban valley bowls. That wet, sooty blanket of hydrocarbon flatulence was to persist through the weekend.

For Saturday, as on Friday, the Utah Division of Air Quality issued "unhealthy" breathing condition alerts. Mandatory bans were ordered for solid-fuel burning devices and open burning in general, and motorists were asked to reduce trips, avoid idling or opt for mass transit. Industries were urged to optimize their operations to limit their emissions.

The elderly, very young and those with heart or respiratory conditions were advised to avoid outdoor activity in the affected areas.

Along with the smog came early morning fog that left road surfaces slick. Multi-vehicle crashes on Interstate 15 closed three southbound lanes near the Salt Lake-Utah County line about 7 a.m. The Utah Highway Patrol said no serious injuries were reported, though two people were taken to the hospital to be checked out.

The wreckage had been cleared by 8:30 a.m. and normal traffic flow resumed.

Morning fog was expected again on Saturday along the Wasatch Front. High temperatures were expected to rise no higher than the mid-20s, with overnight lows 5-10 degrees.

Indeed, record-low temperatures continued to make the National Weather Service's archives. Provo sank to 6 degrees early Thursday morning, a degree lower than its 7-degree mark for 1923; the Utah Test and Training Range recorded a low of minus-6, breaking a 4-degree mark set in 2007.

Southern Utahns caught a break, though. Under sunny skies , temperatures were to rise to near 40 on Saturday with overnight lows about 20 degrees — the same as Friday's forecast.

The Utah Avalanche Center began Friday with "considerable' risk grades for potentially deadly snowslides in the backcounty of the Ogden, Salt Lake, Provo, Unitas and Moab mountains. The Logan and Skyline districts were rated at "moderate" risk for avalanches.

For more extensive, detailed forecast information, clkick on this link to visit the Tribune's weather page.

remims@sltrib.com

Twitter: @remims