Avalanche Forecast

Issued: Feb 25th, 2020 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs.

Avalanche Canada ahanna, Avalanche Canada

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Avalanche danger may be improving but human triggered avalanches remain possible. Caution around wind loaded features in the alpine and on convexities at upper treeline elevations.

Summary

Confidence

Moderate - Uncertainty is due to the extreme variability of wind effect on the snowpack.

Weather Forecast

Tuesday night: A trace of snow. Light to moderate west wind. Freezing level 900 m.

Wednesday: A trace of snow. Light to moderate southwest wind. Freezing level 1300 m.

Thursday: 5-10 cm new snow. Moderate west wind. Freezing level 1400 m.

Friday: Mostly cloudy. Light southwest wind. Freezing level 1500 m.

Avalanche Summary

Minimal avalanche activity observed Tuesday.

Reports from Monday include a natural wind slab avalanche cycle to size 2, as well as skier controlled, accidental and remotely triggered storm slabs size 1-2 on northeast aspects in the alpine and upper treeline. This MIN post includes a photo of a skier triggered wind slab.

Snowpack Summary

20-40 cm of settling snow sits over old surfaces consisting of surface facets, isolated patched of surface hoar in sheltered areas or sun crusts on solar aspects. Wind affect in the alpine is extremely variable, with reports ranging from minimal soft slab development to wind scoured surfaces and hard slabs. Soft snow is well preserved on sheltered shady aspects.

Faceted snow and crusts exist near the base of the snowpack in much of the region. This layer is believed to be largely dormant at the moment.

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Start on smaller terrain features and gather information before committing to bigger terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

20-40 cm of settling snow sits over old surfaces consisting of surface facets, isolated patched of surface hoar in sheltered areas or sun crusts on solar aspects. Where wind has aided slab development, natural, human triggered and even remotely triggered avalanches have been observed on this layer. Slabs will be deepest where wind has loaded lee terrain features in alpine and exposed treeline areas.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 26th, 2020 5:00PM