Avalanche Forecast

Issued: Mar 28th, 2020 4:00PM

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

Avalanche Canada astclair, Avalanche Canada

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New snow and strong winds are creating dangerous avalanche conditions. This is the final forecast for the season.

Summary

Confidence

Low - Uncertainty is due to limitations in the field data.

Weather Forecast

Saturday night: Cloudy, 5-10 cm of new snow, moderate southwest wind gusting strong at ridge-tops, freezing level dropping to 1300 m, alpine temperatures reach -5 C.

Sunday: Cloudy, up to 5 cm of new snow, moderate southwest wind gusting strong at ridge-tops, freezing level climbing to 1400 m in the afternoon, alpine temperatures reach -6 C.

Monday: Cloudy, 5-15 cm of new snow, moderate southwest wind, freezing level climbing to 1200 m in the afternoon, alpine temperatures reach -6 C.

Tuesday: Cloudy, scattered flurries with a trace of new snow, light southwest wind, freezing level climbing to 1000 m in the afternoon, alpine temperatures reach -7 C.

Avalanche Summary

Slab avalanches are a concern on slopes with accumulations of new snow, especially in wind-loaded terrain. Mountain travel and field observations over the past week have been very limited. Little is known about recent avalanche activity.

Snowpack Summary

New snow and strong southwest winds are building reactive storm slabs and creating dangerous avalanche conditions. 

Snowfall from earlier in the week was highly variable across the region with some areas receiving 15-25 cm and adjacent valleys getting as little as 0-5 cm. Some of the heavier accumulations fell in the south part of the region. This snow covered a variety of previous snow surfaces including crusts, warm snow, and wind-affected snow. It may also sit above some small surface hoar on shaded, sheltered slopes. Overall, there is some uncertainty about how well the snow has bonded to these interfaces.

Northern parts of the region have had a deep instability lingering at the base of the snowpack for most of the season, however this layer has gained strength over the past month (with the last reported avalanche on Feb 17).

Terrain and Travel

  • Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.

Problems

Storm Slabs

An icon showing Storm Slabs

New snow and strong southwest wind are forming unstable storm slabs. Slab formation is most likely in wind-drifted areas. There is uncertainty about how well these slabs will bond to underlying interfaces.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 30th, 2020 5:00PM