Avalanche Forecast
Issued: Nov 21st, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Wind Slabs.
Tereza Turecka,
Strong to extreme south-west winds expected to add load to the recently formed wind slabs and persistent slab as there is still a lot of snow available for transport.Pay extra attention to cross loaded features.
Summary
Weather Forecast
Monday: Flurries. Accumulation: 8 cm. Alpine temperature: High -6 °C. Wind southwest: 20 km/h gusting to 60 km/h.Tuesday: Isolated flurries. Precip: Trace. Alpine temperature: Low -13 °C, High -7 °C. Wind west: 15-35 km/h.Wednesday: Isolated flurries. Precip: Trace. Alpine temperature: Low -14 °C, High -10 °C. Ridge wind southwest: 15-35 km/h.
Snowpack Summary
Strong to extreme SW winds heavily affecting any surface snow. The snowpack has now formed persistent slab in sheltered areas and wind slab particularly in wind loaded features. A 2cm thick crust 80cm down is found up to 2500m or higher. Weak facets below the crust result in sudden collapse test results.
Avalanche Summary
Today's patrol down the Parkway did not observe any new avalanches. Friday's team observed two size 2 persistent slab avalanches on windloaded features in the alpine and treeline.
Confidence
Problems
Deep Persistent Slabs
60-80cm of storm snow from Nov 13-15th has settled into a persistent slab condition. Field tests are showing sudden collapse on a crust down 50-80cm over weak facets. The snowpack is still at its infancy and the prudent thing to do is be cautious.
- Avoid thin rocky or unsupported terrain features.
- Use caution on open slopes and convex rolls
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Watch for wind loading especially in cross-loaded features, at ridge tops and in the alpine with recent West and SW winds. Strong to extreme winds are expected to persist into Monday gight with a lot of snow still available for transport.
- Use caution in lee areas. Recent wind loading have created wind slabs.
- Avoid steep lee and cross-loaded slopes
Aspects: North, North East, East, South East, North West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Nov 22nd, 2021 4:00PM
