Avalanche Forecast

Issued: Dec 15th, 2018 3:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

New snow, strong winds and a weak base are creating ideal conditions for wind slabs. Natural activity is slowing but conditions remain touchy for skier triggered avalanches.

Summary

Confidence

High -

Weather Forecast

Light snowfalls with moderate to strong SW winds will continue over the next few days. Temperatures will remain above seasonal in the -5C range.

Avalanche Summary

A few new avalanches up to sz 2.5 were observed in Alpine terrain on Saturday. These slabs were mainly failing at the interface of the recent storm snow on N and E aspects.

Snowpack Summary

An additional 4cm fell overnight on friday and 10cm during the day on Saturday. Over the past 5 days 46cm of snow has fallen at treeline with warm temps and strong SW winds. Widespread windslabs have developed and we have seen lots of cracking, reports of whumpfing, and skier controlled avalanches on the Dec 10th surface hoar and facet interface down 40-60cm. Recent natural avalanche have stepped down to the Oct crust with fracture depths over 1m. The new windslabs and persistent slabs will take a few days to settle out and strenghten.

Problems

Wind Slabs

Warm temps, new snow and strong winds are creating widespread skier triggerable slabs in open areas.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

There are a number of weak facet layers lurking deep in the snowpack. Be sure to dig and assess before jumping into ski terrain. Even pieces of small terrain could kick out a decent size avalanche.

Dig down to find and test weak layers before committing to a line.Avoid unsupported slopes.Minimize overhead exposure during periods of heavy loading from new snow, wind.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 16th, 2018 2:00PM