Inversion may worsen this week, NWS says

SALT LAKE CITY — With Utah’s wintery temperatures this week, there will also be some inversion patterns and low air quality in the valleys.

There is some high pressure making its way across the country this week, which will trap cooler air and pollution in Utah’s valleys creating an inversion. National Weather Service meteorologist Sam Webber said this is because the pressure moving across the country is warmer air.

⚠Building high pressure will create the conditions necessary for inversions to occur. This will allow pollutants to accumulate, reducing air quality. A storm system that will impact Utah toward the end of the week may improve the conditions and clear out the inversions. #utwx pic.twitter.com/swx7KSZjzl

— NWS Salt Lake City (@NWSSaltLakeCity) November 26, 2023

“The warmer temperatures with height really inhibit air moving upwards,” he said. “It kind of acts as a little lid on top of the surface.”

That “lid” will trap pollutants and cause the weakened visibility we see during an inversion. According to Webber, the recent snowfall has made it stronger.

“We have much cooler temperatures at the surface and warmer temperatures moving overhead that are gonna make that temperature difference a lot greater and give us a stronger inversion,” Webber said.

Utah will finally get some relief this weekend. Webber said there will be a storm system passing through the state.

“What storms do is create instability in the atmosphere and (help) air move upwards,” he said. “You think high pressure, [it] usually means sinking air motion. Low pressure, which is typically associated with storms, allows for rising air.”

The storm system will drop temperatures in higher elevations and allow the air to mix and help the inversion to clear.

Related: How Utah’s wildfires and winter inversion impact heart health