Avalanche Forecast

Issued: Mar 21st, 2012 4:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

Conditions are slowly improving but its still not time to jump into bigger features just yet. The deeper weak layers are getting harder to trigger but if you get them to go it will have huge consequences.

Summary

Confidence

Good

Weather Forecast

Freezing levels will remain low with temperatures around -10C at treeline on Thursday. A weak system may pass over the region late in the day giving us a few cm of new snow. Winds will be moderate out of the SW at 3000m.

Avalanche Summary

No new avalanches were observed. There was a cornice collapse on the EEOR taking out the large cornice overhanging Guides route. This likely happened over the past 48hrs when visibility was limited.

Snowpack Summary

Travel up to Burstall pass for the bi-weekly study plot. 265cm of snow at 2400m. 130cm of snow on the HI board. Upper snowpack is continuing to settle and strengthen. Storm snow sheers that were found down 50cm earlier in the week were not reactive in snowpack tests today. 0214SH layer down 125cm and was coming out moderate 19 in deep tap test. The quality of the sheer was also resistant planar. Midpack mainly P+ with no other sheers found.

Problems

Wind Slabs

Wind slabs up to 45cm thick are present in lee and crossloaded features at treeline and above. Avalanches starting in the upper snowpack will likely step down to one of the deeper layers. Recent avalanches have occurred on this layer.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

Surface hoar is generally buried 125-150cm at treeline and above. Triggering this layer is becoming more difficult as it gets more deeply buried. Avalanches in the upper snowpack may step down to this layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Cornices

Cornices have grown significantly in the alpine over the past week. A recent cornice collapse on the EEOR indicates that some have reached critical mass and are now failing.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

2 - 6

Deep Persistent Slabs

The weak basal facets and depth hoar are still present. Large terrain features are areas of concern where a smaller slide could step down and trigger a very large avalanche with deep and wide propagation.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

4 - 7

Valid until: Mar 22nd, 2012 9:00AM