Avalanche Forecast

Issued: Feb 13th, 2016 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Recent avalanche events are proving that it's still touchy out there (see avalanche discussion). Continue to keep your terrain choices conservative as there is a high likelihood of triggering an avalanche. SH

Summary

Weather Forecast

A few cm expected Sunday with freezing levels staying at valley bottom with light gusting strong W winds throughout the day. Winds will increase overnight into Monday as another small pulse (5cm) rolls through.

Snowpack Summary

A surface windslab 10-30 cm thick continues to be reactive in the alpine. A 50-100 cm slab overlies the January 6th weak layer of surface hoar, facets and sun crust and snowpack tests indicate an unstable bond between the two. The lower snowpack is facetted and quite weak, especially in shallower areas.

Avalanche Summary

A number of avalanche incidents with very close calls this week. The most recent was a group of 7 which triggered a size 2 Friday evening, left of the regular final approach slope to Bow Hut. It initiated at 2400m on a NE aspect, was 40-80cm deep (Jan 6th layer), and ran 350m. This fully buried 1 person, and almost fully buried another.

Confidence

Problems

Persistent Slabs

Numerous reports of avalanches triggered on the Jan 6 layer over the last 5 days (less reactive below treeline). In thinner areas, isolated avalanches have been seen to scrub to ground. Less natural activity noted today due to cooler temperatures.

Avoid areas with overhead hazard.Avoid paths that have not avalanched recently.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Wind Slabs

Be mindful of cross loaded features and the lees of ridges where windslabs 10-30 cm thick continue to be reactive. If triggered, there is potential to step down to the persistent weak layer and to ground in thin areas.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 14th, 2016 4:00PM