Dense Fog — San Juan River Basin, Colorado

2025-11-22 · San Juan River Basin, Colorado

Event narrative

Localized dense fog developed within the San Juan River Basin in the early morning of November 22. The KPSO AWOS at the Stevens-Pagosa Springs Airfield reported two brief periods of 1/4-mile visibility overnight due to freezing fog, once near 0100 MST, and again between 0200-0400 MST. No reports of injuries, damages, or fatalities were received.

Wider weather episode

With a low passing to our south, calm winds and clearing skies began to dominate the region. Though the mid-level atmosphere was quickly drying out, low-level moisture persisted in lower valleys across the western slope of the Rockies. Patchy fog was able to develop across portions of northwestern Colorado as a result, and widespread fog developed over portions of southwestern Colorado before quickly burning up after sunrise.

Source: NOAA Storm Events Database, event_id 1300430. Narrative written by the NWS forecast office that issued the report.