Avalanche Forecast

Issued: Apr 6th, 2021 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

Stormy conditions are expected to build fresh and reactive storm slabs throughout the day. Choose conservative terrain and watch for signs of instability such as whumpfing, cracking and recent avalanches.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Tuesday night - Cloudy with flurries / moderate to strong southwest wind / alpine low temperature near -5 / freezing level 900 m

Wednesday - Snow, 15-25 cm / moderate to strong southwest wind / alpine high temperature near -6 / freezing level 1000 m

Thursday - A mix of sun and cloud / light northwest wind / alpine high temperature near -8 / freezing level 1000 m 

Friday - Snow, 10-15 cm / light northwest wind / alpine high temperature near -6 / freezing level 1000 m

Avalanche Summary

With high snow accumulations and strong southwest winds expected on Wednesday, fresh and reactive slabs are likely to increase in reactivity as the day goes on.

A natural avalanche cycle was observed in the region on Saturday during the storm. On Sunday, there were a few size 1-1.5 human triggered wind slab avalanches reported. This MIN describes triggering a small wind slab in large terrain. 

Snowpack Summary

15-25 cm of snow is expected to accumulate throughout the day, adding to the 20 cm that fell over the weekend. The precipitation is likely to fall as rain below around 1000 m. 

The new snow sits on a crust on sun-exposed aspects, and on all aspects below 1600 m, and on soft snow or wind slabs on north aspects. Southwest winds are expected to create fresh and reactive slabs during the day.

Cornices are large and looming along ridgelines. Their release is unpredictable, requiring a large berth if you're travelling above or below them.

Terrain and Travel

  • Watch for changing conditions today, storm slabs may become increasingly reactive.
  • Choose conservative terrain and watch for clues of instability.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Storm Slabs

An icon showing Storm Slabs

Up to 25 cm could accumulate on Wednesday, creating fresh storm slabs that are likely to increase in reactivity throughout the day, particularly in wind loaded areas.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices are large and looming along many ridgelines, and are likely to continue to grow during Wednesday's storm. 

Aspects: North, North East, East, West, North West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 7th, 2021 4:00PM