Avalanche Forecast

Issued: Jan 30th, 2012 8:19AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs, Wind Slabs and Cornices.

danyelle magnan, Parks Canada

Glacier.

Many size 2.5 to 3.5 natural and artillery controlled avalanches occurred yesterday, from all aspects. Many avalanches propagated wider at lower elevations triggering slabs. Artillery also triggered avalanches in adjacent paths showing propagation.

Summary

Problems

Storm Slabs

Over the past 36hours up to 60cm of dense snow was deposited on top of 10cm of weaker low density snow from the 28th. The dense snow is forming a cohesive slab which will be most reactive on steep slopes and convex features.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Wind Slabs

Moderate to strong S-SW winds have prevailed during recent storms resulting in a series windslabs on exposed terrain. New windslabs are forming, and old ones have been buried. Major drifting and crossloading has been observed.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Cornices

A series of storms have provided lots of snow for transport by sustained southerly winds. Cornices are getting very large, and when they fail will provide large triggers capable of triggering deep layers and large avalanches.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

3 - 4

Valid until: Jan 31st, 2012 8:00AM