Avalanche Forecast

Issued: Dec 8th, 2019 4:00PM

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

Avalanche Canada MBender, Avalanche Canada

There is uncertainty with the reactivity of several buried weak layers. Best to adopt a conservative approach while the snowpack adjusts to the increased load from recent snowfalls.

Summary

Confidence

Moderate - Uncertainty is due to the complexity of the snowpack’s structure.

Weather Forecast

Sunday: Mainly clear with cloudy periods, alpine temperature -9, moderate northwest wind.

Monday: Mix of sun and clouds, alpine temperature -7, moderate north wind.

Tuesday: Mix of sun and cloud, alpine temperature -8, light northwest wind.

Wednesday: Cloudy with flurries, alpine temperature -8, light southwest wind.

Avalanche Summary

Reports from Friday indicate skier triggered and natural storm slab avalanches to size 1-2. Additionally there were explosives controlled avalanches to size 3 along the Trans Canada highway corridor on Friday. There were also a few reports of persistent slab avalanches failing on a layer of surface hoar (down 60-100 cm) at treeline elevations.

Snowpack Summary

20-40 cm of new snow from the latter part of last week has covered a layer of feathery surface hoar that has been found at all elevations in some parts of he region. A thick layer of faceted crystals, previously wind-affected surfaces, and/or surface hoar in sheltered areas (around treeline and below) is now 40-80 cm below the surface.

An additional layer of surface hoar may be found in sheltered areas around treeline down 60-100 cm. In some areas this may sitting on a thin crust.

A variety of crusts from late October are buried deeper in the snowpack.

Problems

Storm Slabs

An icon showing Storm Slabs

20-45 cm of new snow accumulating late last week has formed a reactive storm slab. In some areas this may be sitting on a layer of weak surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

There is a lot of uncertainty associated with the reactivity and distribution of a surface hoar/crust layer buried 70-110 cm. This layer is most likely found in sheltered openings around treeline and below.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Dec 9th, 2019 5:00PM