Avalanche Forecast

Issued: Nov 29th, 2017 4:00PM

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

ian jackson, Parks Canada

Banff Yoho Kootenay.

Good ski conditions exist at higher elevations, but watch for early season hazards and stay out of bigger alpine terrain where the halloween crust is still a concern.

Summary

Weather Forecast

A westerly flow will bring consistent, but light precip amounts this week. 5- 10 cm per day with light to moderate west winds in the alpine and freezing levels staying below valley bottom.

Snowpack Summary

Another 10-15cm of new snow overnight on Tues brings the 5-day dry storm snow amount to ~50cm. Moderate winds have been transporting this snow, but windslab formation has been limited in the past 24 hours. The main weakness to watch is the Oct 31 crust/facet layer located about 30cm above the ground which produces easy, planar shear test results.

Avalanche Summary

No avalanches were reported or observed today.

Confidence

Due to the number of field observations

Problems

Persistent Slabs

The snowpack remains unstable in many alpine/treeline areas. Avoid avalanche starting zone areas. We do not expect natural avalanches on this layer in the next 24-hrs, but human triggering remains a serious concern.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

Up to 50cm of recent dry snow is being blown into windslabs in the alpine. We expect these to only be a problem at the higher elevations where they can be easily triggered by skiers in leeward areas.

Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Nov 30th, 2017 4:00PM