Avalanche Forecast

Issued: Dec 7th, 2019 4:00PM

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

Avalanche Canada MBender, Avalanche Canada

Email

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 - Recent weather patterns have resulted in a high degree of snowpack variability within the region.

Weather Forecast

Saturday Night: Scattered flurries, alpine temperature -8, moderate northwest wind.

Sunday: Sunny 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. 

Avalanche Summary

Reports from Friday indicate skier triggered and natural storm slab avalanches size 1-2 on all aspects. There were also a few reports of persistent slab avalanches failing on a layer of surface hoar (down 60-80 cm) at treeline elevations over the past several days. At least one of these was remotely triggered (from a distance). Additionally there reports of explosive triggered avalanches to size 3 in the trans Canada highway corridor.

Snowpack Summary

30-60 cm of new snow from the past few days has covered a layer of feathery surface hoar that has been found at all elevations. A thick layer of faceted crystals, previously wind-affected surfaces, and/or surface hoar in sheltered areas (around treeline and below) is now 50-90 cm below the surface.

An additional layer of surface hoar may be found in sheltered areas around treeline down 70-110 cm. In some areas this may sitting on a thin crust.

A variety of crusts from late October are buried deeper in the snowpack. Total snow depths range from 150-220 cm around tree line.

Problems

Storm Slabs

An icon showing Storm Slabs

30-60 cm of new snow accumulating over the past 48 hours 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 - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A weak layer of crust and surface hoar is 70-110 cm below the surface in many parts of he region. This layer is most likely found in sheltered openings treeline and below.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Dec 8th, 2019 5:00PM