Avalanche Forecast

Issued: Mar 17th, 2016 3:00PM

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

Alberta Parks mike.koppang, Alberta Parks

3 cornice collapses that triggerred sz3 avalanches on underlying slopes were observed on Thursday.  Use caution around these beasts.  Also, when the sun comes out, stability decreases on solar aspects so pay attention to whats overhead.

Summary

Confidence

High - Timing or intensity of solar radiation is uncertain on Friday

Weather Forecast

The freezing level is forecast to be around 1600m tomorrow with alpine temperatures around -5C.  The sun will likely come out so plan for some decreasing stability on Solar aspects later in the day. 

Avalanche Summary

There was a few new sz 3 avalanches occurring on eastern aspects that were likely caused by cornice collapses overnight.  One of these avalanches (on Snow Peak) was over 400m wide and up to 1m deep. 

Snowpack Summary

Variable wind effect in lee and cross-loaded features in the Alpine and isolated areas at Treeline. Some reverse wind-loading due to recent northerly winds. Numerous buried crusts are found on solar aspects which were producing generally moderate shears down 32 and 50cm in snowpack stability tests today at 2300m. Cornices continue to grow with several failures observed over the past several days.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs up to 40cm thick are present in lee and cross-loaded features in alpine areas and in very specific locations at treeline. Some reverse wind-loading due to recent northerly winds.
Caution in lee and cross-loaded terrain near ridge crests.>Choose well supported terrain without convexities.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Basal facets and the Jan 6th FC interface are likely to be triggered from thinner snowpack areas.
Avoid convexities or areas with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Cornices

An icon showing Cornices
Cornices are large and we have seen a few collapse of late with the warmer temperatures and continued loading. When these do fail the heavy loads on underlying slopes may awaken the basal instabilities and produce very large avalanches.
Pay attention to overhead hazards like cornices.>Stay well back from cornices.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Mar 18th, 2016 2:00PM