Avalanche Forecast

Issued: Mar 28th, 2020 4:00PM

The alpine rating is high, 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.

Summary

Confidence

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

Weather Forecast

Saturday night: Cloudy, 20-30 cm of new snow above 1100 m, strong southwest wind, freezing level dropping to 1000 m in the afternoon, treeline temperatures reach -3 C.

Sunday: Mix of sun and cloud, 5-10 cm of new snow, moderate southwest wind, freezing level rising to 1000 m in the afternoon, treeline temperatures reach -2 C. 

Monday: Mostly cloudy, 10-20 cm of new snow, moderate southwest wind, freezing level rising to 800 m in the afternoon, treeline temperatures reach -5 C. 

Tuesday: Mostly cloudy, 5-10 cm of new snow, light southwest wind, freezing level rising to 800 m in the afternoon, treeline temperatures reach -5 C. 

Avalanche Summary

Slab avalanches are a concern on slopes with accumulations of new snow, especially in wind-loaded terrain. No recent avalanches have been reported, but mountain travel and field observations have been very limited.

Snowpack Summary

The weekend storm brought snow, rain, and strong southwest winds to the region, elevating the avalanche hazard. Snowfall amounts have proven difficult to forecast but sufficient enough to build widespread, reactive storm slabs at upper elevations. 

15-25 cm of snow from earlier in the week covers a variety of snow surfaces including crusts, warm snow, and wind-affected snow. There is some uncertainty about how well the new snow has bonded to these interfaces. The snowpack is well-settled. Snowpack depths diminish rapidly with elevation, with 300-400 cm at treeline and no snow below 700 m.

Terrain and Travel

  • Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Problems

Storm Slabs

An icon showing Storm Slabs

New snow and strong wind are expected to build widespread, reactive storm slabs at upper elevations. There is uncertainty as to how well these slabs will bond to underlying interfaces. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

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