Avalanche Forecast

Issued: Dec 6th, 2018 4:06PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Little change in store for the next few days. There have been isolated skier remote avalanches in steep alpine terrain over the past week, and some thin wind slabs in high elevation lees to watch for. Conditions are good but its not open season.

Summary

Weather Forecast

The dry cold weather continues. Cool temperatures will persist with no significant precipitation in sight for the weekend. Winds remain light out of the W for the next couple days.

Snowpack Summary

No new snow in several days. 5-10 cm of recent snow has been redistributed into thin wind slabs in immediate lee areas at treeline and above. The October 26th crust/facet layer is ~30 cm above ground. In many areas the entire snowpack is faceting and becoming quite weak. Snow depths range from 50-85 cm at 2000 m.

Avalanche Summary

Another skier accidental was reported Wednesday on the slopes skiers left of Bow Summit. It was a size 1.5 and likely failed on the Oct 26th crust/facets. Additionally some small thin wind slabs were reported in the Observation Peak and Sunshine Village areas. A few small loose dry avalanche have also been observed.

Confidence

Due to the number and quality of field observations

Problems

Deep Persistent Slabs

It is still possible to trigger this layer but it will be in isolated, steep spots and often adjacent to thin rocky areas. Be cautious in steep terrain where a stiffer, more cohesive slab exists over the weak faceted snow at the base of the snowpack.

Whumpfing is direct evidence of a buried instability.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 2

Wind Slabs

Some light wind transport on Tuesday created small thin wind slabs in lee areas at higher elevations. They appear to be reactive to ski cutting but are generally thin and small.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Dec 7th, 2018 4:00PM