Avalanche Forecast

Issued: Dec 2nd, 2017 3:18PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs.

swerner, Avalanche Canada

Lizard-Flathead.

If new snow accumulates to 15 cm or more consider the danger rating to be CONSIDERABLE. Storm slabs may be reactive to rider triggers. With limited observations and a variable snowpack use a conservative approach to route selection.

Summary

Confidence

Low - Due to the number and quality of field observations

Weather Forecast

Sunday: Mix of sun and cloud with convective flurries up to 5-10 cm. Ridgetop winds light from the North. Freezing levels 800-1200 m and dropping to valley bottom overnight.Monday: Mostly sunny. Ridgetop winds light from the West. Alpine temperatures near -10 and freezing levels at valley bottom. Tuesday: Mostly sunny. Ridgetop winds light from the North West. Alpine temperatures near -10 and freezing levels near valley bottom. Temperature inversions may exist through next week. Check out the Mountain Weather Forecast for more detail.

Avalanche Summary

On Saturday, explosive control triggered storm slab avalanches up to size 1.5 on northeasterly slopes. Reactive storm slabs and wind affected snow may exist on leeward slopes through the forecast period. Please submit your observations this weekend to the Mountain Information Network. Give info, get info.

Snowpack Summary

Up to 50 cm of accumulated storm snow has fallen on the crust that formed a week ago. The buried crust is supportive and approximately 10 cm thick. It extends from 1600 m to mountain top elevations on all aspects. Lots of uncertainty exists with the new snow sticking to the crust. Winds are likely redistributing the new snow above treeline and possibly forming wind slabs on leeward slopes and terrain features. The average snowpack depth at treeline is 60-80 cm while a deeper snowpack exists in the alpine.

Problems

Storm Slabs

Storm slabs may have a poor bond to a buried crust down 30-60 cm and could be reactive to rider triggers. Winds have redistributed the new snow forming thicker slabs on leeward features (N-NE) above 1600 m.

Be careful with wind loaded areas, especially near ridge crests and roll-overs.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 3rd, 2017 2:00PM