Avalanche Forecast

Issued: Jan 7th, 2013 8:16AM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Recent snow and strong winds have changed the avalanche danger for the first time in weeks. It is time to adjust terrain choices. A significant storm is expected Tuesday night which will further elevate the Danger Level.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Between 40 and 50cm of new snow is possible on Tuesday night and Wednesday. Strong to extreme SW winds are expected to accompany the snowfall. Temperatures in the alpine will be near -14 on Tuesday.

Avalanche Summary

Widespread loose dry slides up to size 2.0, but averaging size 1.5 ,on all aspects and all elevations. Some minor slab propagations were observed to be triggered by sluffs on steep lee and cross loaded features.

Snowpack Summary

Up to 25cm of storm snow has fallen in the past 48hrs. Storm slabs are present in the alpine and treeline areas as well as open areas below treeline. Some cracking was observed today in the alpine. The surface hoar and surface facets are now buried and are a layer of concern, especially at treeline and below.

Problems

Storm Slabs

25cm of recent storm snow with strong to extreme W and NW winds have created storm slabs at all elevations. Cracking was observed in the alpine today and these slabs will become increasingly sensitive to human triggering over the next couple of days.

Assess start zones carefully and use safe travel techniques.>Avoid lee and cross-loaded terrain near ridge crests.>Avoid freshly wind loaded features.>

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Loose Dry

Steep terrain on all aspects are producing loose dry avalanches up to size 2.0. Occasionally these slides are also triggering small slabs. This is of particular concern in terrain traps. Ice climbers and skiers should be aware of overhead terrain.

Avoid areas with overhead hazard.>Pay attention to overhead hazards like cornices.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Deep Persistent Slabs

Recent test results show the Nov rain crust to be generally unreactive, but this could change with the addition of new snow load over the next several days. Carefully evaluate shallow snowpack areas.

Be aware of thin areas that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Jan 8th, 2013 2:00PM