Update: Denver ended up warming to about 60 degrees, what National Weather Service forecaster Robert Koopmeiners said was needed to dissipate the inversion and lower particulate pollution over the city.
Denver's air quality was rough on Friday morning. At 5 a.m., the "air quality index" measured at Champa Street and Broadway peaked at a level that is considered bad news for anybody's lungs. The event was regional and driven by fine particulate pollution in the air.
The culprit: an inversion. This is a not-uncommon phenomenon in Denver's winter months. Basically, the balance of warm and cold air in the atmosphere flips, pushing pollution that was high up in the atmosphere toward the ground. It's not that there's more solid matter in the air, it's just that it's concentrated where we breathe.
Robert Koopmeiners, who answered the phone at the National Weather Service's Boulder headquarters, told us that we may have trouble rebounding from this. It's a pretty bad inversion, he said, and temperatures may not rise to the level required to fully disband it. He estimated 60 degrees Fahrenheit would do the trick.
"We're gong to get a high of 50 today," he said. "It might be rough. It might be hard today to get rid of this thing."
He added that, as of this morning, Denver International Airport was surrounded by three miles of fog and haze.
"Yeah, a pretty good one," he said. "At least it's not Cleveland in the late '60s!"