Avalanche Forecast

Issued: Nov 23rd, 2012 8:57AM

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

robert hemming, Parks Canada

Glacier.

Summary

Weather Forecast

A pacific frontal system will move over the area today. Cloudy moderate SW winds with moderate snow fall easing later today. Unstable air in the wake of the front will result in snow showers with locally moderate winds this afternoon and overnight.

Snowpack Summary

Now over 90mm of load on the Nov 6 crust, down 60-100cm.� Sudden planar and sudden collapse results have been reported above this layer recently. A cohesive storm slab has formed and is reactive where it overlies the Nov 16 sun crust.

Avalanche Summary

2 size 2 natural observed above the highway corridor yesterday one a result of a cornice fall in the alpine. Loose point releases observed. 2 reports of skier accidental slab avalanches on steep wind loaded features in the alpine yesterday size 1.5

Confidence

Problems

Wind Slabs

Riders triggered 2 wind slabs yesterday on steep southerly slopes in the alpine yesterday. Suspect bed surface is a thin sun crust that was buried on November 16

Assess start zones carefully and use safe travel techniques.Avoid cross loaded features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Recent reports of whumphs, sudden collapse and sudden planar results on this layer. Careful assessment of the bond with this layer and the slab above should be conducted before committing to any slope over 25 degrees.

Assess start zones carefully and use safe travel techniques.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Nov 24th, 2012 8:00AM