Dense Fog — San Juan River Basin, Colorado

2024-12-27 · San Juan River Basin, Colorado

Event narrative

Shortly before 3AM local time, the KPSO AWOS at Stevens Field in Pagosa Springs, CO began reporting visibilities less than 1/4 mile. Satellite imagery also indicated a large area of dense fog forming throughout the San Juan River Basin. As the sun rose, road cameras provided by the Colorado Department of Transportation allowed for visual confirmation of dense fog, particularly along the US Highway 160 corridor. No reports of injuries, damages, or fatalities were received.

Wider weather episode

Several winter storms passed through eastern Utah and western Colorado during the last week of 2024, bringing widespread precipitation in the form of rain and snow to the region. Each system reinforced areas of rich low level moisture trapped in lower elevation valleys across western Colorado. With colder temperatures and clearing skies in the wake of each wave, the rich low level moisture condensed in dense fog that lingered well into the daylight hours before finally lifting.

Source: NOAA Storm Events Database, event_id 1226690. Narrative written by the NWS forecast office that issued the report.