Avalanche Forecast

Issued: Mar 29th, 2012 4:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

The snowfall forecast has been scaled back to only approx 10cm over the next 24 hours. Forecast models for the next few days vary but unless we see significant snowfall or rapid warming we anticipate Avalanche danger will remain static.

Summary

Confidence

Good - Intensity of incoming weather is uncertain for the entire period

Weather Forecast

Avalanche Summary

Visibility was limited by snow and flat light but at least one new Size 2 soft slab release was observed in the Smith-Dorrien area on a northeasterly aspect.

Snowpack Summary

A few test profiles were completed today, most in the treeline elevation zone. Depending upon aspect, one or more thin melt-freeze crusts could be found in the top 20cm of the snowpack. On sheltered northerly aspects the snow surface remains dry and no crusts were evident. The February surface hoar layer burial depth is variable from 75-150cm deep and Compression tests on this layer revealed either HARD or No failures. On lee aspects soft slabs 30-40cm thick have been observed have formed with as a result of winds over the past few days.

Problems

Storm Slabs

Storm slabs are present on lee features in alpine areas and wind exposed areas at treeline. These slabs sit on a variety of buried layers including crusts and surface hoar. The bond between the new snow and these layers is variable.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

The February surface hoar is buried 120-150cm at treeline. This interface has been strengthening and becoming harder to trigger, but shallow snowpack areas are still a concern. Cornices or smaller avalanches could step down to this layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Valid until: Mar 30th, 2012 9:00AM