Avalanche Forecast

Issued: Nov 16th, 2018 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Good powder for skiing. Watch for localized slabs sitting over the Oct. 26 crust and facets. It is still possible to trigger large avalanches in more aggressive terrain.

Summary

Weather Forecast

A NW flow at upper elevations will see temperatures plummet for Saturday morning (-20C along the divide). Winds will be mainly light increasing to moderate and no snow is expected. Sunday and Monday will see a warming trend (especially in the Foothills) but no significant precipitation in the forecast.

Snowpack Summary

25-40cm of recent snow with variable wind effect overlies a faceted snowpack 60-80 cm deep at treeline and up to 150cm on the Icefields. The Oct. 26 crust and facets sit roughly 30 cm above the ground up to 2800m on shady aspects, and above 2800m on solar aspects. This crust has been dormant recently, producing only hard results in field tests.

Avalanche Summary

Lake Louise ski hill had a couple of explosive triggered avalanches (size 2.5) that ran far, which failed on either the October crust or the facets on or near the ground. The explosives used were small, 1kg hand charges.

Confidence

Problems

Deep Persistent Slabs

This problem can be found up to 2800m mainly on shady aspects. We haven't seen much in the way of avy activity over the last few days, with the exception being some sobering explosive controlled avalanches at the ski hills (see avalanche table).

If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.Whumpfing is direct evidence of a buried instability.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Nov 17th, 2018 4:00PM