Avalanche Forecast

Issued: Mar 13th, 2012 5:00PM

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

Tim Haggarty, Parks Canada

Waterton Lakes.

Up to 40 cm of new snow has fallen with moderate to strong Westerly winds. Continued rapid loading with a warming trend on Thursday will maintain High Hazard. Natural activity is quite likely and with firm bed surfaces events may run far.

Summary

Problems

Storm Slabs

The new snow has come in with warm temps. Expect this to develop into a soft slab rapidly as loading continues. The previous warm and windy weather has created a firm bed surface for these slabs to run on.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

New snow in the last 48 hrs has been accompanied by moderate to strong W-SW winds. Expect soft slabs forming above the previous hard slabs and crusts in open areas.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Suncrusts and Surface Hoar now down 80 to 140 cm. With the recent rapid loading the potential for this interface to produce serious avalanches is quite real. Consider the potential for this layer to be triggered by smaller events.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Mar 16th, 2012 5:00PM