Avalanche — Southwestern San Juan Mountains, Colorado

2020-12-19 · Southwestern San Juan Mountains, Colorado

Event narrative

A soft slab avalanche was triggered on the north face of Battleship, southeast of Ophir, Colorado by a group of backcountry skiers after a week long period of light to moderate snowfall. The avalanche was small relative to the path and destructive enough to injure, bury or kill a person. The avalanche reached depths from 12 to 20 inches, was about 700 feet wide and ran 1600 vertical feet, from the alpine into a below treeline creek bed. The Colorado Avalanche Information Center has rated the avalanche danger as Considerable (Level 3) above treeline and Moderate (Level 2) below treeline. Three skiers were either caught or partially caught by the avalanche with only one survivor.

Wider weather episode

A series of early season winter storms was followed by a period of dry weather beginning on November 23. The dry pattern resulted in warm days, cold nights and light winds. The weather pattern changed on December 10 as a series of Pacific storms passed through the area. This brought new snowfall amounts from 15 to 20 inches across the area. A small group of backcountry skiers unintentionally triggered a soft slab avalanche. This would be the second fatal avalanche in two days in Western Colorado.

Source: NOAA Storm Events Database, event_id 931719. Narrative written by the NWS forecast office that issued the report.