Utah forecast: Fog, smog and then an air-clearing storm

Patchy morning fog, gradually clearing smog and continued daytime temperatures near freezing were forecast for Utah heading toward the week's end.

The good news is that a new storm system is expected Friday to bring fresh snowfall and break up the pollution-trapping inversions shrouding the valleys of the Wasatch Front. Until then, however, the Utah Division of Air Quality was still forecasting "Red," or unhealthy breathability conditions for Salt Lake, Davis, Box Elder, Cache, Utah and Weber counties on Wednesday and Thursday.

Duchesne, Tooele and Uintah counties earned "Yellow," or compromised air quality grades.

Southern Utahns looked for partly cloudy skies and increasing sunshine with a chance of rain by Thursday night. Daytime highs were in the 60-degree range.

The Utah Avalanche Center began Wednesday by rating the mountains of Ogden, Salt Lake City, Provo, Skyline and Moab at "moderate" risk for dangerous snowslides, while Logan and the Uintas earned a "considerable" risk grade. Early forecasts for Thursday had all areas at "moderate," except for a "considerable" grade given to the Uintas.

Salt Lake City's Wednesday high temperature was pegged at 38 degrees and Thursday's forecast was for 35; Ogden looked for 36 and 33 degrees, respectively; Provo 44 and 38; Logan 30 and 25; Wendover 38 and 30; Duchesne 34 and 28; Cedar City 45 and 47; St. George 63 and 62; and Moab 43 degrees both days.

remims@sltrib.com