Date of Observation: 12/01/2021
Name: Eric Murrow Zach Kinler
Zone: Northwest Mountains
Route Description: Rustlers Gulch up westerly slopes to Cassi Peak area
Observed avalanche activity: Yes
Avalanches: No new avalanches. We visited an avalanche on a west-facing slope at 12,700 feet that was previously reported on 11/29. This slab avalanche appeared to be triggered by a very small loose avalanche. The snow surface at the crown was soft and faceted. Cross-loading formed the slab on a break in the terrain. Of note with this avalanche was a melt/freeze crust near the ground with 2mm facets sandwiched between the crust and the overlying slab. The lowest crust served as the bed surface. The slab structure was isolated on this slope to the cross-loaded terrain break. A ridge immediately west of this avalanche causes the slope to be shaded from the afternoon sun.
Weather: Clear skies and mild temperatures. Very calm air mass with hardly a breath of wind.
Snowpack: We almost entirely traveled on westerly slopes from 9,700 – 12,700 feet. We carried our skis across mostly dirt with occasional patches of faceted snow behind shady tree fences until 11,000 feet. Above 11,000 the snow coverage became just continuous enough to skin. Upper elevation, sunny slopes were mostly bare ground and upper elevation northerly slopes were thin, but with continuous coverage. We ascended and descended immediately adjacent to the avalanche and found a stack of crust and facets 30 – 50 cms deep without slab structure.
Photos:
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- Close up view of the natural avalanche that we investigated. West aspect at 12,700 feet.
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- Panorama from the basin with the dry sunny slopes on the right and shady slopes on the left with thin but continuous coverage.
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- Crown profile from the viewers left portion of Cassi Peak avalanche previously reported on 11/29
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- Dude enjoying the t-shirt weather at 12,000 feet.
