Avalanche Forecast

Issued: Mar 12th, 2014 4:39PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Natural activity has slowed down, but human triggering remains likely. Give the snowpack some time to heal. SH

Summary

Weather Forecast

West winds will be light gusting strong on Thursday with no snow expected. Alpine temperatures will stay below freezing throughout the day. There should be a fair amount of sun throughout the forecast region.

Snowpack Summary

85-100cm of storm snow has fallen in the Sunshine, Kootenay and Yoho areas, with 40-60cm around Lake Louise and Bow Summit since Mar 2nd. This storm snow has overloaded the Feb 10th layer of facets, surface hoar and sun crust, and in thinner snowpack areas, the deeper basal facet layer, causing large, destructive avalanches with wide propagations.

Avalanche Summary

Some solar activity up to size 2 in the Mount Field area today. We have seen a large natural avalanche cycle up to size 3.5 over the past week, with wide propagations on many different aspects and elevations. Also, skier triggered avalanches including remote triggered slides to size 3 have been occurring frequently in the past few days.

Confidence

Problems

Persistent Slabs

Natural activity has slowed down on this layer, but we have seen large avalanches over the past few days with the new storm snow overloading the Feb.10th interface. In some cases we have seen this step down to the basal facets in thin snowpack areas.

Avoid areas with overhead hazard.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Wind Slabs

Mod to strong Westerly winds will be stiffening the snow surface and transporting snow to lee aspects. These will be sensitive to human triggering for the next few days.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Wet

Watch locally for daytime warming in steep, solar features.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 2

Valid until: Mar 13th, 2014 4:00PM