Avalanche Forecast

Issued: Apr 4th, 2017 4:25PM

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

Lisa Paulson, Parks Canada

Banff Yoho Kootenay.

Hazard is rated Low in the morning below tree-line. It may rise to Considerable in the afternoon with rising freezing levels and temperatures, especially if there is any sun affect.

Summary

Weather Forecast

Another good freeze tonight. Light flurries and showers begin tomorrow with freezing levels rising to 2100 m. They will remain there through Wednesday and Thursday night as the front passes through the region. In the alpine, expect 5-10 cm on Thursday and 5 cm Friday and rain below treeline. Local amounts may vary across the region.

Snowpack Summary

On shaded aspects or in the high alpine, up to 20 cm of low density snow sits over a firm 100 cm+ slab resting over weak basal facets at all elevations. Tests show sudden collapse results in these facets. A melts freeze crust is widespread below treeline & steep solar aspects at treeline & above. Windslabs are specific to immediate alpine lees.

Avalanche Summary

A little cooler today overall and no new avalanches were observed.

Confidence

Problems

Deep Persistent Slabs

The snowpack throughout the region has a weak base and remains suspect. Approach all avalanche terrain with suspicion and exercise conservative route choices. This problem will persist for the foreseeable future.

Be wary of slopes that did not previously avalanche.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Cornices

Cornices are big and we are getting regular reports of cornices failing. A large cornice fall could trigger a bigger avalanche on the slope below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 5th, 2017 4:00PM