Avalanche Forecast

Issued: Dec 23rd, 2018 4:08PM

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

kdevine, Avalanche Canada

Lizard-Flathead.

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

SUNDAY NIGHT - Cloudy with clear periods and isolated flurries, up to 5 cm / southwest to west winds, 20-40 km/h / alpine low temperature near -6Â°c. MONDAY - Cloudy with sunny periods / light southwest winds / alpine high temperature near -8Â°c. TUESDAY - A mix of sun and cloud / light southwest winds / alpine high temperature near -8Â°c, low temperature near -10Â°c. WEDNESDAY - Cloudy with sunny periods and isolated flurries / light southwest winds / alpine high temperature near -9Â°c, low temperature near -11Â°c.

Avalanche Summary

Several explosives triggered avalanches size 1-2.5 were reported in the region on Saturday. No new natural avalanches were reported on Saturday.Several natural and explosives triggered avalanches to size 2 were reported on Friday.

Snowpack Summary

10 cm of snow fell during the day on Sunday. This new snow has been redistributed into soft wind slabs in lee areas at treeline and alpine elevations. 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

60-110 cm of snow sits on a weak layer that consists primarily of facets (sugary snow).

Use caution in areas where the snowpack transitions from deep to shallow.Use conservative route selection, choose moderate angled terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Dec 24th, 2018 2:00PM