Avalanche Forecast

Issued: Dec 29th, 2018 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

An avalanche cycle is expected from this weekend's storm. Avalanches are expected to be touchy for a while. Avoid avalanche terrain.

Summary

Weather Forecast

The storm should taper by Sunday but some residual avalanche activity is expected. Cooler incoming air is expected to squeeze the last humidity out of the air giving us light flurries on Sunday. Colder conditions on Monday.

Snowpack Summary

The majority of the BYK region is a 40-60cm slab of stiff snow or new windslab overlying 40cm of weak facets and depth hoar. This nasty combination continues to produce whumphing and easy test results. Deeper snowpack areas are stronger, but have a 60-80cm slab over top of the Dec10 surface hoar/facet layer.

Avalanche Summary

Several avalanches were noted on Friday but their extent and size was obscured.

Confidence

Problems

Deep Persistent Slabs

This problem dominates the central and eastern part of the forecast region and will continue to do so for some time. Natural activity on this layer has decreased but human triggered avalanches on this layer are still possible.

Be wary of slopes that did not previously avalanche.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Wind Slabs

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 2.5

Valid until: Dec 30th, 2018 4:00PM