Avalanche Forecast

Issued: Mar 18th, 2012 4:00PM

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

mike.koppang, Alberta Parks

Kananaskis.

Conditions are improving but there are still lots of places backcountry users can get into trouble. Most accidents happen immediately following a storm when the weather improves. Conservative decision making and careful snowpack evaluation is key.

Summary

Confidence

Good

Weather Forecast

No new snow is in the forecast for the next 48hrs. Winds were continue to be light out of the SW with temperatures being seasonal with daytime highs at treeline around -8C.

Avalanche Summary

Sluffing up to size 1 out of steep unskiable terrain throughout the forecast area. No new slab activity was observed.

Snowpack Summary

Upper snowpack continues to settle. Easy to Moderate sheers persist within the storm snow but they are strengthening. On solar aspects the March 11th temperature crust down 40-50cm is producing easy to moderate sheers. The valentines day surface hoar layer is now buried 140-170cm and is becoming more stubborn to trigger.

Problems

Storm Slabs

Light to moderate winds have created storm slabs up to 40cm thick along ridgelines and in crossloaded features at treeline and above. Avalanches starting in the upper snowpack will likely step down to one of the deeper problem layers.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

Surface hoar buried up to 160cm continues to be a major concern in the snowpack. A dense slab now sits on top of this layer. Avalanches in the upper snowpack will likely step down to this layer causing a destructive avalanche.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 6

Persistent Slabs

The March 11th Temperature crust is buried down 50cm on solar aspects. The bond of the upper snowpack to this crust is highly variable and requires careful evaluation as you travel.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

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

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

Unlikely - Possible

Expected Size

3 - 7

Valid until: Mar 19th, 2012 9:00AM