Avalanche Forecast

Issued: Feb 6th, 2024 4:00PM

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

BF, Avalanche Canada

Banff Yoho Kootenay, Banff, East Side 93N, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N, Field, Little Yoho.

10-20cm of recent snow which overlies a generally supportive crust has improved ski quality.

Recent winds from the south may have formed isolated wind slabs at ridge top on North facing features, more likely in Southern areas of the region.

Although the hazard is generally Low, there is still a chance of triggering deeper layers.

Summary

Confidence

Moderate

Avalanche Summary

No new natural avalanches were observed from a field trip to Lake O'Hara.

Both Sunshine and Lake Louise reported some results from ski cutting in alpine terrain up to size 1.5 from old wind slabs and reloaded bed surfaces. No new natural avalanches were observed.

Snowpack Summary

10-20cm of recent storm snow sits on a recently formed crust, which is widespread at all elevations, except for north aspects above 2500 m. The cooling temperatures have improved the stability of the mid-pack, but the January persistent facet layers down 20-50 cm, and deep persistent facet and depth hoar layers at the base of the snowpack, are still present at treeline and above.

Weather Summary

Scattered flurries continue as southwest ridgetop winds weaken to light through the night Tues.

Wed: Widespread flurries develop for the region. Trace accumulations across the range. Light ridgetop winds switch from southwesterly to southeasterly. Freezing levels will be at the valley bottom.

Thurs: Scattered flurries and ridgetop winds will be light from the SE for the region.

For more mountain wx click HERE

Terrain and Travel Advice

Avoid areas where the snow feels stiff and/or slabby.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Closely monitor how the new snow is bonding to the crust.

Problems

Persistent Slabs

The cooling temperatures have reduced the likelihood of the persistent slab problem which is comprised of facets that formed end of December and mid-January. However, these weak layers have not gone away entirely, especially at upper elevations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

The weak facets and depth hoar are still present at the base of the snowpack in areas at treeline and above. These are most likely to be triggered from thin snowpack areas or by large triggers like cornices. If triggered this could result in a large avalanche, so evaluate steep terrain carefully.