Banff Yoho & Kootenay National Park Avalanche Forecast

Issued: Nov 23rd, 2021 4:00PM

Tue Nov 23rd Current Conditions
Alpine Considerable Treeline Moderate Below Treeline Low
Wed Nov 24th 2 Day Outlook
Alpine Considerable Treeline Moderate Below Treeline Low
Thu Nov 25th 3 Day Outlook
Alpine Considerable Treeline Considerable Below Treeline Low

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

Good skiing exists in sheltered areas at treeline. Last weeks storm snow has settled into a very supportive early season snowpack. Concern over the deep persistent weakness still exists and this problem should be treated with respect.

Summary

Weather Forecast

Winds will increase to moderate to strong from the W / SW on Wednesday with only a few cm's of new snow forecasted. On Thursday and Friday, we should see anywhere from 5-20 cm of new snow with strong SW winds. Temperatures will stay cool until Friday when freezing levels are forecast to rise to ~ 1700m.

Snowpack Summary

5-15 cm of fresh snow Monday overnight sits on a variety of surfaces: a rain crust below ~2000m , a sun crust on steep solar aspects, windslabs in the alpine and exposed treeline areas and settled snow everywhere else. Melt/freeze crusts and/or facets lurk at the bottom of the snowpack. Snowpack depths at tree-line average 60-110 cm

Avalanche Summary

No new avalanches observed on a field trip in the Dolomite Shoulder area on Tuesday or reported to us by local ski hills.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible

Expected Size

1 - 2

Buried windslabs exist in the alpine and down into some tree-line locations, and increasing winds on Wednesday will build new ones in alpine and treeline terrain that is exposed to the wind.

  • Use caution in lee areas. Recent wind loading have created wind slabs.
  • Watch for surface cracking and stiffer surface layers of snow. Avoid wind loaded terrain.

Aspects:

North, North East, East, South East.

Elevations:

Alpine, Treeline.

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Likelihood

Possible - Unlikely

Expected Size

1.5 - 2.5

Avalanches failing on this layer are tapering off, however, forecasters are still receiving occasional reports of them occurring. The latest reports are not larger than size 2, but uncertainty surrounding this problem still exists.

  • Be aware of the potential for wide propagations due to the presence of hard windslabs.
  • Be wary of slopes that did not previously avalanche.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Valid until: Nov 24th, 2021 4:00PM

Forecast Trend

The latest forecast danger ratings, broken down to elevation. See how an elevation is trending.