Banff Yoho & Kootenay National Park Avalanche Forecast

Issued: Mar 27th, 2021 4:00PM

Sat Mar 27th Current Conditions
Alpine Considerable Treeline Considerable Below Treeline Considerable
Sun Mar 28th 2 Day Outlook
Alpine Considerable Treeline Moderate Below Treeline Low
Mon Mar 29th 3 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Low

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Wind Slabs, Storm Slabs and Loose Wet.

The avalanche hazard will increase through the day Sunday with incoming snow, strong winds and high freezing levels.

Summary

Weather Forecast

A low pressure system will build over the forecast region Sunday. This weather system will bring precipitation in the form of rain at lower elevations and snow above 2000m with up to 30cm of accumulation. This new snow will come with strong to extreme winds at mountain top. As this system dissipates Monday, temperatures will cool.

Snowpack Summary

15-40cm of snow has fallen within the last week. This snow sits over a sun crust on solar aspects, facets on North aspects and a temperature crust at lower elevations. Incoming snow ,wind and warm temps will add load to the current snowpack and widespread wind effect at upper elevations. Rain saturated snow is expected at lower elevations.

Avalanche Summary

Reports of several natural and skier triggered wind slabs in the alpine to size 1.5 on Saturday.  We expect avalanche activity to increase at all elevations as a storm develops Sunday.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Very Likely

Expected Size

1 - 2.5

Widespread wind slab development in the alpine and exposed treeline areas is expected as strong to extreme winds and up to 30cm of new snow loads lee slopes on Sunday.

  • Be careful with wind loaded pockets, especially in steep confined alpine terrain.
  • Use caution in lee areas. Wind loading could create slabs.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Storm Slabs

An icon showing Storm Slabs

Likelihood

Very Likely - Likely

Expected Size

1 - 2

Expect 20-30cm of storm slab development in sheltered areas. We are uncertain of how this new snow will bond to the old surface.

  • The storm slab may be more sensitive to human triggering on solar aspects where it sits on a crust

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Loose Wet

An icon showing Loose Wet

Likelihood

Very Likely - Likely

Expected Size

1 - 2

Rain and warm temperature will break down the snowpack at lower elevations and increase the likelihood for loose wet avalanche activity. This problem could release to ground causing small but destructive avalanches.

Aspects:

All aspects.

Elevations:

Treeline, Below Treeline.

Valid until: Mar 28th, 2021 4:00PM

Forecast Trend

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