Southwest Colorado is again shrouded by smoke from wildfires across the West, particularly in California and Utah. But a cold front settling into the region will help improve air quality as the weather shifts from heat to chilly breezes, according to the National Weather Service office based in Grand Junction.

There is the potential for smoke to coalesce over the southwestern portion of the state again Wednesday afternoon, but not nearly to the degree that it has over Labor Day weekend and into Tuesday, said meteorologist Megan Stackhouse with the National Weather Service.

According to the Weather Channel website, rain and snow moving into the area late Monday night will result in a significant decrease in smoke concentrations in central and northwestern Colorado by Tuesday, with “slower improvement expected for southwestern Colorado.”

The National Weather Service issued an air quality alert that has been extended to 4 p.m. Tuesday, warning Southwest Coloradans to stay indoors if smoke becomes thick, especially young children, elderly people and those with heart conditions.

The website states that if visibility is less than 5 miles due to smoke, it has reached levels that are unhealthy.

The air-quality index monitor on the Cortez Fire Station peaked at 172 on Monday, compared with an AQI value of about 37 for the past several days.

While rain is expected for most of Montezuma County this week, the San Juan Mountains could see up to a foot of snow over the next couple of days, Stackhouse said.

Temperatures dropped rapidly from the low 90s to the mid-60s between Monday and Tuesday, and will drop to the mid-50s on Wednesday.

The cold front is hitting much of the West, including Utah, Nevada, Arizona, New Mexico and Wyoming, and it is expected to assist with wildfire mitigation in these areas.

California will continue to experience the same dry heat conditions.

ehayes@the-journal.com