In Roy, Shannon Quintana had three immediate family members who called in to work sick because of the foul air, "and I have been having sinus problems for a week now."

As pollution levels grew Monday, the state Division of Air Quality validated all the sniffling, sore throats and strained breathing. Officials issued a red alert for air quality in Salt Lake and Davis counties that continues through today. Yellow air-quality advisories continue in Utah, Weber and Cache counties.

The red warning prohibits the use of most woodburning stoves and urges everyone not to use pollution-producing engines, like cars, if possible. The advisory also cautions residents of affected counties to avoid prolonged outdoor exercise - a message especially important for the old, the young and people with heart and lung ailments, who tend to be more sensitive to the harmful affects of pollution.

The National Weather Service Salt Lake City forecast office said mild weather systems might bring some relief late today to the temperature inversion that keeps pollution trapped in the valleys.

"It may improve somewhat," said forecaster Chris Young. "But I don't think it's going to scour out [the valley pollution] completely."

The weather service predicted the chance of snow in northern Utah would be 30 percent, and up to 50 percent in mountain areas such as Park City. Daytime temperatures are expected to be in the low- to mid-30s, with patchy fog and clouds. Nighttime temperatures are expected to be in the low 20s.

And, if wind, temperatures and snow don't help to clean out the air today, northern Utah may be in for significant pollution days through the rest of the week.

The weather appears likely to be similar to Monday's - only the buildup of pollution will be greater.

To get the latest on the advisories, check the air-quality division's Web page, http://www.airquality.utah.gov.

Parry, the mother of five, is glad it is not soccer or baseball season, when her children would be antsy to play outside.

"I wish we had cleaner air," she said, resigned. "I wish we weren't in a valley where we had these inversions."

But Quintana is sick of it.

"We were having dinner the other night, and I told my husband it would really benefit us all to move south. Seriously."

fahys@sltrib.com