Avalanche Forecast

Issued: Feb 9th, 2015 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Wind slabs and storm slabs at Treeline and above are sensitive to human triggering. Cautious route-finding advised. Keep an eye on freezing levels as warmer temperatures will lead to an increase in danger level.

Summary

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

A mix of sun and cloud expected on Tuesday with freezing levels near 1900m. Very light flurries are possible with light to moderate westerly winds. Alpine temperatures should reach -3 celsius. Slightly snowier conditions expected Wednesday before a warming trend on Thursday and Friday pushes the freezing levels up to 2200m.

Avalanche Summary

No new natural avalanches observed today, but visibility was quite limited. Ski cutting produces small slabs in steep terrain at Treeline.

Snowpack Summary

2cm of new snow through the day with very little wind. Temperatures at treeline rose to above freezing by early afternoon. The snowpack is settling rapidly and the surface snow is moist below 2000m on all aspects but this condition reaches higher on solar aspects. Recent storm snow of up to 60cm is bonding well below treeline, but not as well at treeline and above where moderate shears persist at the January 31st interface. Also at treeline and above new wind slabs have formed in recent days which are reactive to ski cutting. Cornices have experienced significant growth in recent days and several large avalanches have been triggered by cornice failures.

Problems

Storm Slabs

Recent storm snow up to 60cm deep is not bonding well at the Jan 31st interface at Treeline and above. This interface is highly variable across the forecast region. Whumpfing is common indicating that remote triggering is possible.

Avoid freshly wind loaded features.>Avoid runouts where triggering slopes from below is possible.>Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 4

Wind Slabs

Recently developed wind slabs in open areas at Treeline and in the Alpine are sensitive to triggering as indicated by ski cutting results today. These wind slabs could initiate a larger avalanche by steeping down to more deeply buried weaknesses.

Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.>Choose well supported terrain without convexities.>Avoid lee and cross-loaded terrain near ridge crests.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Deep Persistent Slabs

Large loads, such as cornices, could trigger full depth avalanches. Several very large avalanches have occurred in recent days that involved the entire winter's snowpack.

Pay attention to overhead hazards like cornices.>Be aware of thin areas that may propogate to deeper instabilites.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

3 - 6

Valid until: Feb 10th, 2015 2:00PM