When will smoke from the Yellow Lake wildfire emerge from Utah? Winter storm should help.

Wildfire smoke continues to impact Utahns on both sides of the Wasatch Mountains this week, but a winter storm should soon provide clarity.

The Yellow Lake Fire near Francis in Summit County grew to 31,000 acres as weekend winds and warm temperatures continued to fuel the fire, which has been ongoing since Sept. 28.

In communities near the fire, from Kamas to Tabiona, officials warned people not to go outdoors in the morning and early afternoon as air quality is considered “unhealthy” for most groups.

“It’s worse in the morning. We are seeing improvements as the days go by. And then it’s worse again at night,” said Carolyn Kelly, Department of Natural Resources air resources advisor for the Yellow Lake Fire. We're in a pattern where this big cloud is rising. Then an inversion occurs at night, the smoke settles, moves down the valley and impacts communities.”

In other words, Kelly said, wait until after lunch to walk your dog or run errands.

Along the Wasatch Front, smoke from the Yellow Lake Fire and the 1,000-acre Cherry Creek Fire in Juab County is expected to create hazy but less damaging conditions through Monday evening, said Christine Kruse, the lead meteorologist for the National Weather Service in Salt Lake City. Salt Lake County's air quality index was “moderate” Monday morning.

It's hard to say how long this smoke will last.

“It depends so much on fire behavior that it’s hard to model,” she said. “We’ll just have to see what the different fires do.”

However, meteorologists are assuming that a storm will arrive on Thursday night, which should provide relief.

Snow is expected above 5,500 feet. Kruse said that could mean some snowflakes were floating in the air along the banks and between 6 and 12 inches in the Cottonwood Canyons.

“It should be a good snowstorm,” she said. “If people aren't used to driving in the snow – and they're not – this is just a reminder that we need to start driving like it's winter.”