Avalanche Forecast

Issued: Mar 27th, 2012 4:00PM

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

Alberta Parks jeremy.mackenzie, Alberta Parks

Up to 20cm of recent snow has formed storm slabs due to warm temps and wind loading. These slabs will be sensitive in steep, unsupported terrain. Carefully evaluate the bond between the slabs and the underlying crust or surface hoar layer.

Summary

Confidence

Fair - Due to limited field observations

Weather Forecast

Light flurries and high freezing levels (2000m) on Wednesday. winds will also be strong out of the SW. Another storm on Thursday could bring 20cm of snow over the course of the day.

Avalanche Summary

Isolated solar triggered loose wet slides on steep solar aspects up to size 1.0.

Snowpack Summary

15cm of new snow at treeline over variety of surfaces, including crusts on solar aspects and pockets of surface hoar in sheltered northerly aspects. Visible wind affect in alpine areas indicating wind slab development. Snowpack is settling rapidly with warm temperatures.

Problems

Storm Slabs

An icon showing 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

An icon showing 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 28th, 2012 9:00AM