Avalanche Forecast

Issued: Jan 17th, 2017 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

We are expecting a significant rise in avalanche danger (if the forecasted snow fall actually arrives!). Very conservative route selection is in order.

Summary

Confidence

Low - Intensity of incoming weather systems is uncertain

Weather Forecast

Wednesday will be warm and very windy with a mainly cloudy sky. The big unknown is the amount of snow fall. Some models are calling for almost no snow accumulation, while other models are predicting 15 to 20cm by Wednesday afternoon. Most models agree that Thursday and Friday will be cloudy with only light precipitation.

Avalanche Summary

Two naturally triggered size 2.0 slab avalanches were observed today. One occurred on a West aspect of Mt Engadine in an Alpine feature. The other avalanche occurred at Treeline on a steep North aspect. Both of these avalanches appeared to have failed on the basal facets and ranged between 60 an 80cm deep.

Snowpack Summary

Trace amounts of new snow have fallen in the past 24hrs and very light flurries were falling this afternoon. The snowpack is settling due to the recent warm temperatures. Surface snow was moist on solar aspects up to 2100m and this may extend higher in elevation (this is unconfirmed). Intense snow transport was observed at ridge crest and it is very likely that further wind slab development has occurred in the Alpine. The remainder of the snowpack remains weak and facetted, and it is likely that an avalanche initiating in the upper snowpack will steep down to the basal layers.

Problems

Storm Slabs

Expected snowfalls of up to 20cm and strong SW winds will create storm slabs in lee and cross-loaded features. Given the weak layer that most of these slabs will lie on, avalanches could be easy to trigger.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas in the alpine and treeline. Storm snow is forming touchy slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Deep Persistent Slabs

Deeply buried weak layers dominate the snowpack. Avalanches are more likely triggered from shallow snowpack areas and step down to the basal facets and involve the entire winters snowpack.

Be aware of thin areas that may propogate to deeper instabilites.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Loose Dry

Sluffing is expected in steep terrain, potentially on all aspect Significant entrainment could occur given the weak nature of the existing snowpack.

Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 18th, 2017 2:00PM