Remotely triggered Persistent Slab, Wet Slab, and shallow Wind Slabs

CBAC CBAC Observations

Date of Observation: 03/18/2022
Name: Eric Murrow Ben Pritchett

Zone: Northwest Mountains
Route Description: Kebler Pass area. Mount Owen in the Ruby Range and Kebler Pass Road corridor.

Observed avalanche activity: Yes
Weather: A mix of sun and thin high and mid-level cloud cover. Temps slightly above freezing at valley bottom and below freezing temps on Mount Owen.
Snowpack: We traveled out to Mount Owen to inspect an avalanche that was reported to run at 11am on an east slope of Mount Owen. Investigating this slide it appeared that a group of snowmobilers/snowboarders likely triggered this avalanche remotely from low angled terrain around 600 feet away. It failed in the February facet layer; the slab ranged from around 50cm to 110cm thick (estimated as we did not measure across the entire crown face). The slab and the slope were shallower than expected based on snowfall totals this winter for the Irwin area. This avalanche was large in size (D2) and could have easily buried a person.

Late in the afternoon, an avalanche was reported to hit Kebler Pass Road. This avalanche was a Wet Slab that was likely remotely-triggered by a snowbike based on a nearby snowbike track. This avalanche failed in the February facets as well, and they were wet from meltwater when the crown was inspected.

Avalanches: In addition to the remotely triggered Persistent Slab on an east aspect above treeline on Mount Owen, the Wet Slab on an east aspect below treeline above Kebler Pass Road, we observed two fresh snowboarder-triggered slabs in the recent storm snow. Both were only a few inches thick and small in size.