Avalanche Forecast

Issued: Dec 6th, 2019 4:00PM

The alpine rating is high, 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

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Storm snow is expected to accumulate Friday night and through Saturday as a frontal system stalls over the region. This will raise the avalanche danger to HIGH.

Summary

Confidence

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.

Weather Forecast

Friday Night: Snow, 10-20 cm, alpine temperature -3 C, moderate to strong southwest wind.

Saturday: Snow, 10-15 cm, alpine temperature -4, moderate southwest wind.

Sunday: Sunny with cloudy periods, alpine temperature -10, moderate north wind.

Monday: Sunny with cloudy periods, alpine temperature -8, moderate northwest wind.

Avalanche Summary

There have only been a handful of snowpack and weather observations from this area. Natural storm slab avalanches to size 1.5 were observed in the region on Wednesday and Thursday. Expect to see an increase in storm slab and persistent slab avalanches if storm snow accumulates as forecasted.

Snowpack Summary

20-35 cm of new snow falling over the past 36 hours has added to the 20-40 cm of storm snow from early in the week. All this new snow has covered a thick layer of faceted crystals, previously wind-affected surfaces, and/or surface hoar in sheltered areas around treeline and below.

A layer of surface hoar (feathery crystals) may be found in sheltered areas around treeline down 40-70 cm. 

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

Problems

Storm Slabs

An icon showing Storm Slabs

Storm slabs will develop through Friday night and Saturday as snowfall accumulates.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A surface hoar/crust layer, down 35-80 cm may become increasingly reactive with increased loading from new storm snow. This layer is most likely found in sheltered openings.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 7th, 2019 5:00PM