Avalanche Forecast

Issued: Mar 16th, 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.

jeremy.mackenzie, Alberta Parks

Kananaskis.

Wind slab conditions are highly variable. A natural avalanche cycle seems to be tapering off, but conditions are ripe for human-triggering. Choose conservative terrain as full depth avalanches are possible due to lingering deep instabilities.

Summary

Confidence

High

Weather Forecast

Thursday will bring cloudy skies with sunny periods and isolated flurries. Alpine temperatures will reach a high of -8 °C. Ridge-top winds will be out of the west at 25 km/h gusting to 50 km/h. A clearing and warming trend is expected for the weekend with freezing levels rising significantly by Saturday.

Avalanche Summary

A few very small loose dry avalanches from steep Alpine terrain on N and E aspects. Further evidence of a recent (past 48+ hours) natural slab avalanche cycle up to size 3.0 on North, East and South aspects in the Alpine. These slabs vary in thickness from 60 to 100cm and some exhibited significant propagation. Some slides have also stepped to ground after originally initiating on a weakness in the mid-snowpack.

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

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 has occurred due to northerly winds. Overall, wind slab conditions are widely variable.

Choose well supported terrain without convexities.>Avoid steep slopes below cornices.>Caution in lee and cross-loaded terrain near ridge crests.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Deep Persistent Slabs

Basal facets and the Jan 6th interface are possible to be triggered from thinner snowpack areas. Several recent naturally triggered avalanches have failed to ground.

Be aware of the potential for large, deep avalanches.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Cornices

Cornices are large and we have seen a few collapse recently 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.

Stay well back from cornices.>Pay attention to overhead hazards like cornices.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Mar 17th, 2016 2:00PM