Avalanche Forecast

Issued: Jan 17th, 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

Little Yoho.

New snow and wind will create new windslabs. Mid-pack weak layers are still worrisome.

Summary

Weather Forecast

New snow and wind are expected Thursday. 15cm of snow is expected, maybe 20cm by Friday. Temperatures are expected to rise Thursday and then fall again Friday

Snowpack Summary

Recent warm temperatures aloft have settled the upper snowpack, with suncrust formed on S and W aspects. 30-50cm of snow sits over the Dec.15 persistent weak layer of facets and surface hoar. We are concerned about this layer at treeline in Little Yoho where the layer is producing easy to moderate snowpack test results and widespread whumphing.

Avalanche Summary

Avalanche Control on Mt Dennis on Tuesday showed the facets are still very mobile below treeline. No new avalanches were reported today.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Persistent Slabs

This layer is a concern mainly at treeline around Field, Emerald Lake and Little Yoho - this is a very specific band. Natural avalanches are unlikely but human triggered are likely - watch overhead hazard BTL; avalanches can run into the forest.

Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

New snow and wind are expected to create new windslabs on lee slopes near ridgecrests

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 18th, 2018 4:00PM