Avalanche Forecast
Issued: Nov 22nd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
Timothy Johnson,
Warmer temperatures, high humidity, moderate to strong winds and new snow are a good recipe for new windslab development.
Summary
Weather Forecast
Tonight: Flurries.
Accumulation: 6 cm.
Alpine temperature: Low -7 C.
Ridge wind SW: 15 km/h gusting to 50 km/h.
Tuesday: Cloudy with sunny periods and isolated flurries.
Precipitation: Trace.
Alpine temperature: High -6 C.
Ridge wind W: 10-25 km/h.
Snowpack Summary
Strong SW winds stripped all aspects in the alpine. New snow with warm temperatures and moderate winds will likely create new wind slabs. Above freezing temperature to 1700m will likely result in a future crust. A 1-2cm thick crust 80cm down is found up to 2500m or higher. Below this crust are more crusts or facets depending on elevation.
Avalanche Summary
No new avalanches were observed on Monday.
Confidence
Due to the number and quality of field observations
Problems
Wind Slabs
Watch for previous wind loading especially in cross-loaded features. Warmer temperatures, high RH, moderate to strong winds, and new snow will likely be creating new windslabs in the alpine and down into treeline.
- Avoid steep lee and cross-loaded slopes
- Use caution in lee areas. Recent wind loading have created wind slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
60-80cm of storm snow from Nov 13-15th has settled over a series of crusts and weak snow crystals at the base of the snowpack.
- Use caution on open slopes and convex rolls
- Avoid thin rocky or unsupported terrain features.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Nov 23rd, 2021 4:00PM
