Avalanche Forecast

Issued: Mar 20th, 2012 5:29PM

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

Tim Haggarty, Parks Canada

Waterton Lakes.

Forecasts show mixed opinions for warming and precip on Thursday: adjust your plan to the most current forecast before you go. Keeping the angle modest below 1900m gives better skiing over the buried crust.

Summary

Problems

Wind Slabs

This has been the culprit in most of the recent activity. Look for these slabs in open areas on the lee side of features exposed to the wind. In many cases recent wind slabs are sitting on older hard slabs and the bond may not be favorable.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

Below 1900m the recent snow is sitting on a rain crust: the bond here may deteriorate especially with warming. At upper elevations the recent snow is less distinct but layers of different densities are present: dig down to confirm the bond.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Wet Slabs

The forecast calls for warming on Thursday with significant precip: rain up to 1500m? This could weaken the "storm slab" (above) sitting over the crust. It may also weaken the crust allowing the moist snow below it to become involved as well.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Mar 23rd, 2012 4:00PM