Dense Fog in Central Colorado River Basin, Colorado

Areas of dense fog developed along the high-elevation valleys along I-70 during the morning of December 7. The KEGE AWOS at the Eagle County Regional Airport reported two periods of 1/4-mile visibility due to freezing fog. The first occurrence was before sunrise and brief, lasting less than thirty minutes. The second occurrence lasted about an hour, beginning near sunrise. No reports of injuries, damages, or fatalities were received.

A strong plume of atmospheric river moisture arrived on the morning of December 6 from the northwest, bringing rain and snow showers to portions of the Colorado west slope. Overnight, the moisture plume descended southwards, leaving west-central and southwestern Colorado valleys to saturate. Dense fog was able to develop before and near sunrise in these valleys as a result, though poor radiational cooling from cloudy skies kept fog relatively localized and short-lived.