Avalanche Forecast

Issued: Feb 15th, 2018 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Deep lingering instabilities continue in the area. Despite the strong post-storm feel to the upper snowpack, the threat of large, catastrophic avalanches limits travelers to safer, non-avalanche terrain. Please continue to play safe.

Summary

Weather Forecast

Light snow is expected Friday with more wind and cold temperatures. This is unlikely to significantly change the avalanche danger rating in the short term.

Snowpack Summary

Windslabs are common in open areas with loading on easterly aspects. Commonly, a deep slab overlies midpack weaknesses of surface hoar, crusts, and facets.Â The depth of these slabs varies from 75 cm to 150 cm. These layers have been producing very large avalanches over the past week.

Avalanche Summary

Several new avalanches were noted today on the Icefields Parkway associated with recent winds.

Confidence

Problems

Persistent Slabs

A 100-125cm dense slab of January storm snow overlies three weak layers in the mid snowpack: Jan 16, Jan 6, and Dec 15. All are a mix of sun crust, surface hoar and facets depending on the aspect and elevation. These layers could easily be triggered.

Be wary of slopes that did not previously avalanche.Avoid all avalanche terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3.5

Wind Slabs

Strong winds last Tuesday night created widespread wind effect in most areas above treeline. Hard wind slabs exist in the alpine lees.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 16th, 2018 4:00PM