Avalanche Forecast

Issued: Mar 15th, 2012 4:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

20cm of new snow forecast to fall overnight with Strong SW winds. Avalanche danger will remain at HIGH in Alpine areas.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain on Friday

Weather Forecast

5cm of snow fell throughout the day on Thursday and additional 15cm is expected by Friday morning. LIght snowfalls will continue throughout the day on Friday and we should see freezing levels drop as well as temperatures begin to drop. Winds are forecast to be strong out of the SW throughout the day before tapering off later in the day on friday.

Avalanche Summary

No new observations due to limited visibility.

Snowpack Summary

5cm new snow over the past 24hrs. Storm snow totals are now close to 50cm at treeline with the valentines day surface hoar interface down 110cm. Moderate sheer persist within the storm snow down 20 and 40 and moderate sudden planer sheers persist at the valentines day interface down 110cm. In Commonwealth ridge area, at 2400m the surface hoar was down 110cm and up to 10mm big, very evident in the test profile. Propagation saw test 30/110 End indicate that any avalanche that is initiated is likely to propagate across a given feature.

Problems

Storm Slabs

Recent winds and new snow have created storm slabs in alpine and treeline terrain that are sensitive to light loads such as a skier. Slabs up to 50cm thick are being encountered

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 6

Persistent Slabs

Surface hoar buried up to 130cm continues to be a major concern in the snowpack. A dense slab now sits on top of this layer. Remote triggering is a real possibility. Many avalanches have stepped down to this layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 6

Cornices

Cornices have grown significantly in the alpine. Failures continue to occur and have triggered avalanches up to size 3 on the underlying slopes. Give cornices a wide berth and stay well back from corniced ridge crests.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 7

Deep Persistent Slabs

The weak basal facets and depth hoar have re-awakened. 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

Possible - Likely

Expected Size

3 - 8

Valid until: Mar 16th, 2012 9:00AM