Avalanche Forecast

Issued: Dec 20th, 2013 4:21PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Even though the cool temps have tightened the snowpack, the potential to trigger full depth avalanches remains due to the weak base that will be a problem for some time to come. JBW

Summary

Weather Forecast

Cool northwesterly flow with some weak disturbances will continue for the next few days bring little snowfall but cold breezy conditions. Temps warm slightly by Sunday.

Snowpack Summary

Some moderate wind transport is adding to the slabs at treeline and above. This will increase the propagation potential across the start zone features. The weak base with depth hoar and the October melt freeze crust will mean any avalanche will involve the entire snowpack.

Avalanche Summary

No new avalanches were observed today, but we suspect a few more slabs pulling out on steep lee features with the additional loading. Avalanches to size three both natural and explosive triggered have occurred over the last few days some running full path.

Confidence

Problems

Wind Slabs

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.The new snow will require several days to settle and stabilize.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Deep Persistent Slabs

Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 4

Valid until: Dec 21st, 2013 4:00PM