Avalanche forecast

Jasper

Nov 22 – 23, 2021
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Archived · expired 5 years ago

Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low

Highlights

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.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2.5

    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.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–3

    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.

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

Regions covered