Denver Weather: Air Quality Suffers On Wednesday As The Polar Vortex Moves Closer

DENVER (CBS4) - As shallow arctic air remains entrenched along Colorado's Front Range on Wednesday, air quality will worsen as pollution continues to get trapped near the ground. Metro area residents may notice irritation in their throat, nose or eyes.

The Colorado Department of Public Health and Environment has declared the air unhealthy on Wednesday for sensitive groups which includes young children, older adults, and anyone with respiratory problems.

An Air Quality Alert continues until 4 p.m. Wednesday for Boulder, Broomfield, Adams, Denver, Jefferson, Arapahoe, and Douglas Counties. Metro area residents are asked to limit driving non-EV vehicles as much as possible to help reduce pollution.

The air quality issues are directly related to the shallow arctic airmass which is found everywhere in Colorado east of the mountains. Because of the shallow nature of the cold air, it can't reach into the mountains. It also means the air a couple thousand feet above the metro area is warmer than the air near the ground. This phenomenon is called an inversion and is somewhat common in the winter months in the Denver area. When it happens, particulate matter (pollution) gets trapped near the ground because the warm air aloft prevents it from escaping higher into the atmosphere as it usually does.

A quick look at expected high temperatures for Wednesday makes it easy to see where the cold air is and isn't. Many mountain towns like Breckenridge, Vail, and Aspen will be at least 5-10 degrees warmer than the Denver metro rea on Wednesday and the same is expected for Thursday.

As the infamous polar vortex moves farther south and west in the coming days, even colder weather will invade Colorado. The Denver area will experience the coldest weather so far this season with weekend low temperatures falling below zero and highs only in the teens.