Dense Fog in Lower Yampa River Basin, Colorado

Localized dense fog developed within the Lower Yampa River Basin on the morning of January 8. The K4V0 AWOS at the Rangely Airport reported multiple brief periods, an hour long or shorter duration, of 1/4-mile visibility due to freezing fog beginning shortly before sunrise and occurring for a couple hours after sunrise. No reports of injuries, damages, or fatalities were received.

Weak southwesterly flow around a deepening trough brought mid-level moisture over Colorado, prompting snow showers to portions of the region overnight from January 7 to 8. Some weak moisture from previous days' precipitation lingered in some valleys still, and brief breaks in cloud cover enabled enough radiational cooling to saturate some locations. Localized dense fog was able to develop as a result, though lingering cloud cover over central Colorado in the hours around sunrise kept fog development primarily to the lower valleys of western Colorado.