Date of Observation: 11/04/2021
Name: Ben Pritchett
Zone: Northwest Mountains
Route Description: Parked at Schofield Pass, skied up Cinnamon Mountain’s NE bowl.
Observed avalanche activity: Yes
Avalanches: One large avalanche ran during the November 2 storm off Peeler Peak’s northeast face. This soft-looking slab avalanche broke around 800 feet wide and ran around 800 feet downslope. We saw a handful of small avalanches in the storm snow in very steep wind-drifted alpine terrain features.
Weather: Ridgeline Wind Speed: 5-10 mph
Ridgeline Wind Direction: NW
Wind Loading: None
Temperature: 28 F
Sky Cover: Clear
Depth of Total Snow: 65 cm
Weather Description: Balmy late fall day. Bluebird skies. Temperatures rose above freezing at 12,000 feet for around 2 hours. Valley bottom temperatures made it well into the 40’s.
Snowpack: Around a foot of snow fell on Tuesday, November 2 in this area.
On sheltered northerly-facing slopes, the storm snow sits on 2 or 3 dense and supportive old-snow layers. Below the new snow/old snow interface we found a thin layer of facets below a crust which could pose a problem as slabs develop on top of this structure, but it poses no concern at the moment.
Above treeline, these buried old snow surfaces are highly variable, so the recent storm snow sits on bare ground, glaze ice, stiff sun-hardened crusts, or dense old drifts.
On southerly-facing slopes, the storm snow settled to only a few inches, mostly resting on bare ground, or old, slick drifts from the late October storm. These sun-exposed slopes moistened by late morning.
We observed no cracking or collapsing. ECT’s did not propagate below the crust under the storm snow. We did get one ECTP near the ground where we found a sheltered slope with larger facets buried near the ground (see profile), but this structure appears isolated in the terrain.