Avalanche Forecast

Issued: Dec 21st, 2012 8:25AM

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

danyelle magnan, Parks Canada

Glacier.

Periods of sun may trigger small loose avalanches. It may also cause cornices to fail. Avoid areas where the snow feels stiff and punchy. Not only is it possible to trigger these windslabs, but the skiing will be much better elsewhere.

Summary

Weather Forecast

A weak ridge of high pressure combined with an arctic front moving southwards will bring cool temps, moderate southerly winds and some sunshine today. Over the weekend expect temps to remain cool, mostly cloudy skies with periods of sun, light to moderate southerly winds, and a few flurries.

Snowpack Summary

New snow in the last 24hrs has been denser, creating slightly "upside down" conditions. Periods of strong SW winds yesterday formed soft windslabs in immediate lees. The Nov28 surface hoar is down about 80cm where it exists. The early Nov crust is widespread and down about 1.5m. Tests on these layers indicate they would be hard to trigger.

Avalanche Summary

Periods of strong southerly winds triggered large natural avalanches from steep, lee avalanche paths overnight.

Confidence

Problems

Wind Slabs

Spikes in wind speeds in the last 24hrs have created fresh windslabs. Hard slabs exist right at ridgecrests, with soft slabs in the lees. Where they exist, these slabs may be triggered by skiers or riders.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Dry

It's looking sunny out there this morning. Expect small, loose avalanches from steep solar aspects today.

Minimize exposure to sun exposed slopes when the solar radiation is strong.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 22nd, 2012 8:00AM