Avalanche Forecast

Issued: Mar 6th, 2012 8:10AM

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

danyelle magnan, Parks Canada

Glacier.

The snowpack will take time to adjust to the load delivered by the storm. Due to a variety of problems all slopes are suspect and capable of producing large avalanches. Several layers are teetering on the edge of failure and you may tip the balance.

Summary

Problems

Storm Slabs

Since Friday, over 1m of snow has fallen. Temps rose through the storm forming a cohesive "upside down" slab, with moist snow below 1500m. Temps dropped overnight, tightening this slab and forming a crust at lower elevations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Persistent Slabs

The Feb surface hoar layers are over 1.5m deep. Overloaded by the storm they produced very large avalanches. Avalanches are stepping down to these layers. Cornices have grown, will be brittle with the rapid drop in temps, and provide large triggers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 4

Wind Slabs

Strong S winds produced windslabs and deep drifts on open slopes at all elevations. Windloading has rapidly increased the load on persistent weak layers, which will take time to adjust. The weight of a skier may be all they need to avalanche.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Mar 7th, 2012 8:00AM