Avalanche Forecast

Issued: Apr 9th, 2012 4:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Avalanche hazard will rise rapidly Tuesday on solar aspects as freezing levels could reach as high as 3400m. Solar triggered avalanches are expected. The deeply buried surface hoar and basal facets have recently produced large avalanches.

Summary

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

Tuesday and Wednesday will see very high freezing levels, possibly as high as 3400m. Winds should remain mostly light and temperatures will be very warm through the period. A storm front is approaching on Wednesday night.

Avalanche Summary

Numerous loose wet slides were observed on solar aspects up to size 1.5. A size 3.0 naturally triggered slab was observed on the NE aspect of Mt. Cordonnier at 2800m. This slide was 500m wide and over one metre deep.

Snowpack Summary

Crusts exist on all slopes up to 2900m except true north aspects. These crusts were breaking down by noon today. Minimal to no wind affect in the alpine near Aster Lake. Stability tests indicate a moderate shear down 50 to 60cm on an old storm snow interface. The snowpack continues to settle due to mild weather conditions.

Problems

Loose Wet

Loose wet slides related to daytime warming are being observed on solar aspects. Pay close attention to terrain that is overhead as you travel. The intense spring-time sunshine does not take much time to change the snow stability.

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

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 4

Persistent Slabs

The Feb surface hoar and basal facets are again a concern in the snowpack. Solar radiation and large loads, such as cornices, have triggered very large avalanches recently. The spring transition could see more slides stepping down to this layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 7

Wind Slabs

Isolated pockets of wind slabs are present in lee and cross loaded features at higher elevations. Stability tests over the last 2 days indicate that these slabs are sensitive to human triggering in steep, convex and/or unsupported terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Apr 10th, 2012 9:00AM