Avalanche Forecast

Issued: Dec 24th, 2018 3:32PM

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

Avalanche Canada dsaly, Avalanche Canada

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Persistent slabs are tricky to manage and generally require patience and conservative terrain choices. Check out the new Forecaster Blog for a great explanation on how to best manage a persistent slab problem. Click here to read the blog.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

MONDAY NIGHT: Cloudy with clear periods. Light south wind. Freezing level valley bottom.TUESDAY: Mix of sun and cloud. Light southwest wind. Freezing level valley bottom.WEDNESDAY: Cloudy with isolated flurries, trace accumulation. Light southwest wind. Freezing level valley bottom.THURSDAY: Mix of sun and cloud. Light southwest wind. Freezing level valley bottom.

Avalanche Summary

On Friday, several natural and explosives triggered avalanches to size 2 were reported on Friday. On Saturday, several explosives triggered avalanches size 1-2.5 were reported in the region.

Snowpack Summary

Up to 20 cm of new snow is being redistributed into soft wind slabs in lee areas at treeline and alpine elevations. A combined total of 60-110 cm of recent snow has formed a slab that sits on a persistent weak layer that formed in early December. This layer mostly consists of facets (sugary snow) with some isolated areas also containing small surface hoar (feathery crystals). Several other weak layers have been observed in the lower snowpack such as crusts and facets that formed in late October/early November. The potential may exist for avalanches triggered on the persistent slab to step down to these lower layers, resulting in large, destructive avalanches.

Problems

Persistent Slabs

An icon showing Persistent Slabs
60-110 cm of snow sits on a weak layer that consists primarily of facets (sugary snow).
Use conservative route selection, choose moderate angled and supported terrain with low consequence.Pay attention to overhead hazards like cornices which could trigger persistent slabs.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Dec 25th, 2018 2:00PM

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