Denver Weather: More Bad Air! The Infamous Brown Cloud Is Back

DENVER (CBS4) - The Colorado Department of Public Health and Environment has issued an air quality alert for Adams, Araphoe, Boulder, Denver, Douglas, and Jefferson Counties until 4 p.m. Wednesday.

The alert is described as an "Action Day for Particulates". Just like on Tuesday, particulate matter mainly from pollution will be trapped near the ground because of an inversion over the Front Range. Normally air gets colder as you ascend higher into the atmosphere. But when temperatures aloft are warmer than temperatures at the ground, it's called an inversion. That warm air aloft is what traps the particulates near the ground and what causes the brown cloud to be visible for many miles.

Generally speaking, the brown cloud will likely not be as bad as it was on Tuesday but should still be visible for much of the day on Wednesday. Officials are asking all residents in the metro area to limit driving whenever possible and skip any unnecessary trips to help reduce emissions.

Better air quality is expected by late Wednesday as winds shift to the northwest and scour out most of the pollution.