Avalanche Forecast

Issued: Apr 19th, 2013 4:01PM

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

Parks Canada Snow Safety, Parks Canada

Conditions are generally good.  In bigger alpine terrain, watch out for thin wind slabs  that can be triggered in steep terrain.  If the sun pokes out Saturday, watch for increasing hazard on solar slopes. SH

Summary

Weather Forecast

Moderate W-NW winds Saturday with cooling temperatures and freezing levels staying near valley bottom.  Light snow Friday night into Saturday.  Sunday through Monday expect cooling temperatures and light N winds.

Snowpack Summary

A weak freeze this morning with freezing levels up to 2000m. There are areas of wind effect in the alpine and isolated wind slabs can be expected in lee areas above 2400 m which can be triggered in steep terrain.

Avalanche Summary

A field team on the South side of Mt. Patterson ski cut a size 1 thin avalanche out of 45 degree terrain at 3100m today.  A size 2 avalanche was also triggered yesterday which was 50cm thick and  80cm wide, which apparently slid on a crust on a SE aspect.  This was on Mt. Unity in the Lake Louise backcountry at 2500m.

Confidence

on Saturday

Problems

Wind Slabs

An icon showing Wind Slabs
Moderate winds have created areas of thin wind slabs in lee areas above 2400 m.  These slabs were more sensitive to triggering Friday with warmer temps. 
The recent snow may now be hiding windslabs that were easily visible before the snow fell.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 20th, 2013 4:00PM