Avalanche Forecast

Issued: Nov 22nd, 2021 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Deep Persistent Slabs.

Timothy Johnson,

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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

An icon showing 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

Possible

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing 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

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Nov 23rd, 2021 4:00PM