Avalanche Forecast

Issued: Jan 5th, 2015 4:00PM

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

grant statham, Parks Canada

Banff Yoho Kootenay.

More snow forecast for Monday night, and we are soon to approach a tipping point in the avalanche hazard. All the small amounts of snow are adding up. Expect avalanche activity on Tuesday and Wednesday, and be wary of sudden changes.

Summary

Weather Forecast

A system embedded in a NW flow will cross the region starting Monday evening and tapering by Tuesday evening. Expect 10-15 cm of snow and rising temperatures with freezing levels reaching 1400 m in some locations on Tuesday. Winds will be light at treeline, but strong at the 3000 m level. Look for clearing starting on Wednesday.

Snowpack Summary

10-15 cm of snow is forecast to fall overnight on Monday, along with rising temperatures. This will form an easily triggered storm slab in windloaded areas at treeline and above. The lower snowpack is comprised of depth hoar and facets, and will soon to reach a tipping point where the new snow load and warming will begin to trigger the deep layers.

Avalanche Summary

No new avalanches have been observed or reported today.

Confidence

Problems

Storm Slabs

10-15 cm of snow expected on Monday night will combine with the existing surface snow to make a storm slab 30-50 cm deep in alpine areas. Human triggering is possible in gullies and convex slopes at higher elevations.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

The lower part of the snowpack is weak and will be overloaded easily with much additional load. Avoid steep (>35 degree) open slopes at treeline and above. Shallow rocky areas are likely areas to trigger this problem.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Jan 6th, 2015 4:00PM