Dense Fog in Lower Yampa River Basin, Colorado

Around 3AM local time, visibility at the K4V0 AWOS at the Rangely Airport, in Rangely, CO, dropped below 1/4 mile. Satellite imagery indicated that this dense fog was more than localized. As the sun rose, airfield cameras provided by the Federal Aviation Administration, and road cameras provided by the Colorado Department of Transportation added visual confirmation of the extent of the dense fog. This fog lingered well into the daylight hours thanks to a combination of already low sun angle and high clouds preventing what little sun there was from reaching the top of the fog layer. No reports of injuries, damages, or fatalities were received.

The unsettled pattern that characterized the last week of the month of December brought widespread precipitation to eastern Utah and western Colorado with regularity. This precipitation created pools of rich low level moisture trapped in the lower elevation valleys across the region. As skies cleared and temperatures cooled each night, dense fog then developed in each of these valleys, often widespread. Thanks to the low sun angle, this fog would linger well into the daylight hours before finally lifting.