Avalanche Forecast

Issued: Feb 22nd, 2017 3:02PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs, Persistent Slabs and Deep Persistent Slabs.

Alberta Parks michael.olsthoorn, Alberta Parks

Travel with caution when exposed to large overhead hazard.  The weak basal layer has potential to create large scale avalanches.

Summary

Confidence

-

Weather Forecast

A trace of snow is forecast tonight with a mix of sun and cloud for Thursday.  Temperatures for Thursday in the alpine will be -13c with ridge wind from the west at 10km/h.

Avalanche Summary

No observations..

Snowpack Summary

We have up to 20cm of recent snow.  This snow has minimal wind effect below 2500m and overlies a temperature crust on all aspects below 2100m and up to 2300m on solar aspects.  A  strong mid to upper pack overlies a weak base at all elevations. The weak basal facets and depth hoar make up the bottom 70cm of the snowpack at all elevations which gives us little confidence in large terrain if an avalanche is triggered.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs exist on all aspects but tend to be thicker on easterly aspects. These may be up to 50cm thick in heavily loaded areas.
Avoid lee and cross-loaded terrain near ridge crests.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs
This hard slab is spotty in nature. Expect to see it start near treeline and carry on higher. If it does react, it will likely propagate for a long ways.
Be aware of the potential for wide propagations.Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Past avalanches have stepped down to this layer. Thin areas and transitional terrain remain a concern.
Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Feb 23rd, 2017 2:00PM