Avalanche Forecast

Issued: Apr 6th, 2012 4:53PM

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

Tim Haggarty, Parks Canada

Waterton Lakes.

Full winter in the alpine. Hard crusts all aspects to the top of treeline. This is still a winter snowpack. Heating will break down the crusts and elevate hazard. Secure travel over these crusts will be a concern and timing with the heating is key.

Summary

Problems

Wind Slabs

Obvious slabs have developed in open lee areas at higher elevations. Avoid large or planar slopes where these slabs may be more continuous. Feel for harder slabs now hidden by recent storm snow and be cautious with slabs formed over crusts.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Cornices

Large and fragile cornices formed last week with warm moist conditions and strong wind transport. These will be prone to natural failure on windy periods or during warming trends. Carefully consider your route choice while traveling on ridges.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Wet

The upper snowpack is now a series of crusts with weak moist snow in between. Consider crampons and ice axe for safe travel on steep slopes. Be wary of heating that will break down these crusts especially on solar aspects allowing for larger events.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Apr 9th, 2012 4:00PM