Avalanche Forecast

Issued: Dec 18th, 2017 5:20PM

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

michael.olsthoorn, Alberta Parks

Kananaskis.

Caution is advised when approaching bigger terrain. Lots going on at all elevations with this new snowfall.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

There is a winter storm watch in effect. Please visit your local weather site for up to date forecast. Tuesday is forecast to bring more snow (11cm) with -15c in the Alpine. The winds, however, are forecast to switch direction and come from the East at 25-35km/hr.

Avalanche Summary

Three natural loose dry avalanches size 1.5 were observed in the Murray Creek area.The new snow also moved easily under our skis on the hard wind slab in the moraines of Murray Creek.

Snowpack Summary

Early Monday morning, we received 25cm of new snow in the valley bottom and 35cm in the alpine. Some of this snow has started to turn into a slab in the alpine due to wind. All of this new snow is sitting on a variety of surfaces. Remember those hard wind slabs we have been talking about; it is a pretty smooth surface for the new snow to slide on, so be cautious under larger or steeper slopes. Some of this new snow might also be sitting on a sun crust that was formed a week or so ago on steep solar aspects. Also remember the surface hoar that was formed over this 3 week dry spell; it can be found up to 2100m and can be a sliding surface if the slope is steep and planar. Lots going on at all elevations, so be cautious on your approach especially with more snow on the way.

Problems

Wind Slabs

Fresh wind slabs will continue to form with overnight winds and tomorrow 's easterly winds. Be cautious on lee features and also on your normal windward features (reverse wind loading)

Caution in lee and cross-loaded terrain near ridge crests.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

Likely

Expected Size

1 - 2

Loose Dry

New snow will sluff easily in steeper terrain at higher elevations as well as below 2150m where the weak layer of large surface hoar crystals exists. Ice climbers should avoid climbs with overhead hazard.

Avoid travelling on ledges and cliffs where sluffing may have severe consequences.Be cautious of sluffing in steep terrain.Be careful with wind loaded pockets while approaching and climbing ice routes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

This layer is widespread in terms of its location in the terrain. The new snow load will not likely be enough to activate this layer yet, but be cautious of thin areas where triggering may be more possible.

Be cautious in shallow snowpack areas where triggering is more likely.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 19th, 2017 2:00PM