Avalanche Forecast

Issued: Feb 6th, 2019 4:40PM

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

mbender, Avalanche Canada

Cariboos.

There is a potential for triggering large avalanches at lower elevations due to the presence of a buried weak layer that exists mainly at treeline and below.

Summary

Confidence

High - The weather pattern is stable

Weather Forecast

THURSDAY - Mainly cloudy with light flurries / light southwest winds / alpine high temperature near -15FRIDAY - A mix of sun and cloud / moderate northeast wind / alpine high temperature near -18SATURDAY - A mix of sun and cloud / moderate northeast wind / alpine high temperature near -20

Avalanche Summary

A persistent weak layer that was buried in mid January continues to be reactive to human triggers. This layer is sensitive enough for avalanches to be triggered remotely (from a distance). Human triggered avalanches up to size 2 were reported on both Sunday and Monday. This layer has been the most reactive at treeline and below.Widespread avalanche activity was reported on Saturday. Natural avalanches to size 3 and human triggered avalanches to size 2 were reported. Many of these failed on the mid January persistent weak layer. There is a great MIN report here detailing the reactivity of the mid January layer in Allen creek on Saturday.Additionally, there are two great MIN reports that outline how reactive the mid January layer was on Friday. They can be found here and here.

Snowpack Summary

30-60 cm of recent new snow is sitting on surface hoar (feathery crystals), facets (sugary snow) and a crust on sun-exposed slopes. In many areas, recent strong winds have redistributed the new snow and formed wind slabs on all aspects due to shifting wind directions.The most notable feature in the snowpack at this time is a persistent weak layer that was buried in mid January, which is now buried 50-80 cm. This layer consists of surface hoar and a crust on sun-exposed slopes. It is most prominent at treeline and below, and continues to produce avalanches.

Problems

Persistent Slabs

50-80 cm of snow sits above a weak layer of surface hoar and crust that was buried in mid January. This layer continues to be reactive to human triggering.

Choose low angled terrain.Any steep opening in the trees should be treated as suspect right now.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 3

Wind Slabs

30-60 cm of recent snow has been redistributed by northeast winds.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.If triggered, wind slabs may step down to deeper layers and result in even larger avalanches.

Aspects: South East, South, South West, West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 7th, 2019 2:00PM