Utah forecast: Continued cold, with worsening valley pollution

A poetic tag team of Sandburg and Shakespeare might sum up Utah's mid-week, inversion-plagued forecast this way: "The smog comes on little, hacking cat feet … something wicked this way comes."

As a high pressure front aloft tightens its grip on the state's urban valleys, cold air and automobile and industrial emissions are trapped. With each day the inversion continues, pollutants are building toward unhealthy levels.

The Utah Division of Air Quality issued a spate of "air quality action" advisories for Thursday, repeating those from Wednesday, and conditions were not expected to improve until fresh storms move into the region over the weekend, when temperatures are expected to warm to at least freezing in Salt Lake City.

In Salt Lake, Davis, Utah, Cache and Weber counties mandatory bans on solid fuel burning devices, as well as fire pits, fire rings and campfires were in place. DAQ also urged motorists to restrict driving in favor of mass transit, and industrial operations to minimize emissions.

Voluntary air quality action alerts were out for Box Elder and Uintah counties with environmental officials asking homes and businesses to limit burning and emissions, and drivers to consolidate trips.

The continuing inversions are not only increasing haze over metropolitan areas but keeping temperatures frigid. The National Weather Service on Wednesday reported that past week's average of daily highs and lows were 10 to 20 degrees below normal in Salt Lake City alone. The normal high for this time of year in Salt Lake City is 39 degrees.

Indeed, cold weather records continued to fall. The Utah Test and Training Range's early Tuesday morning low of minus-10 beat a 5-degree mark set in 2009; Alpine's minus-3 bettered a minus-2 (2009); Bountiful had a minus-1, retiring its 4-degree record (2009); Zion National Park's 8-degree reading out-chilled the previous 11-degree low (1972); and Lake Powell's Bullfrog Marina tied its 1978 record of 9 degrees.

The range's daytime high of 19 was well below the 2007 record of 30 degrees; Provo had 20, beating 22 degrees (2009); Price hit 17 (22, set in 1972); and Alpine tied its 22-degree record (2009).

The Wasatch Front's forecast for Thursday called for highs in the upper-20s to low-30s and overnight lows of 15-20 degrees, about 5 degrees warmer than Wednesday's predictions.

Southern Utahns also expected a slightly warmer Thursday with highs in the upper-30s to low-40s and overnight lows in the upper-teens.

The Utah Avalanche Center elevated its risk ratings for potentially deadly mountain snowslides to "considerable" throughout the state through Wednesday night, with the exception of Logan, which was "moderate."

For more extensive forecast information, visit the Tribune's weather page at sltrib.com/weather.

remims@sltrib.com

Twitter: @remims