Avalanche Forecast

Issued: Dec 12th, 2013 8:00AM

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

chris gooliaff, Parks Canada

Glacier.

Lots of snow available for transport. If the winds pick up, watch for touchy windslabs developing in lee areas.

Summary

Weather Forecast

Mainly cloudy with scattered flurries today. Winds will pick up to moderate values from the SW. Temperatures are continuing to rise, but freezing levels will remain at valley bottom for at least another day.

Snowpack Summary

25-30cm of storm snow sits over the December 8 surface hoar layer at lower elevations and over variable wind slabs up high. The storm snow is mainly low density with some soft slab developing in the alpine. The November 28 surface hoar layer is down around 35-40cm over a facetted mid-lower snowpack. The Nov 12 surface hoar layer is down 60-110cm.

Avalanche Summary

A couple of size 1.5-2.5 slab avalanches were observed from the steep start zones off Mt MacDonald and Cougar Corner yesterday. Sluffing of the low density surface snow was observed in unsupported terrain, steeper than 35 degrees.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

With winds from the SW picking up today and a large amount of light snow to transport, we expect soft slabs to develop in lee features at and above tree-line.

Be cautious as you transition into wind affected terrain.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

Surface snow has been seen to be sluffing fast and entraining the underlying loose facets. Heads-up in gullies and above cliffs.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Be aware of party members below you that may be exposed to your sluffs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

The early November surface hoar still lingers near the base of the snowpack. It may be triggered from areas with a shallow snowpack. If it does trigger, it could bring a large slide with it.

Be aware of thin areas that may propogate to deeper instabilites.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 4

Valid until: Dec 13th, 2013 8:00AM