Avalanche Forecast

Issued: Feb 22nd, 2021 4:00PM

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

Ian Jackson,

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New snow has refreshed the ski quality, but has been accompanied by lots of wind and sits on a weak facet layer in many locations.

Choose conservative terrain from which to assess conditions following this significant storm

Summary

Weather Forecast

A cold front will bring a good pulse of precipitation on Monday night (5-20 cm with highest amounts in the north and west) accompanied by strong westerly winds. Tuesday looks unsettled with light precipitation and easing winds. Wednesday looks to be cold, calm and clear before the next storm approaches Wednesday evening into Thursday.

Snowpack Summary

30-50 cm of storm snow over the last three days along with strong to extreme west winds has created windslabs in exposed alpine and treeline areas. This sits on top of either old wind effect in areas that were previously wind effected or soft facets in previously sheltered areas. The Jan. 27th interface of facets/sun crust is now down 50-90 cm.

Avalanche Summary

Limited visibility today, but an avalanche cycle occurred Sunday night within the storm. Bourgeau Left Hand ice climb ran size 2-3 (couldn't see the fracture line but debris ran below the climb). Ski hills were reporting limited results to size 1, mainly as soft wind slabs or storm slabs.

Confidence

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

Problems

Wind Slabs

An icon showing Wind Slabs

Strong to extreme west winds created wind slabs in the alpine and at tree line. An additional 10-20cm with wind is forecasted Monday evening. We suspect this will be touchiest in previously sheltered areas where the underlying facets were biggest

  • Use caution in lee areas. Recent wind loading has created wind slabs.
  • Pay attention to overhead hazards like cornices which could trigger slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Storm Slabs

An icon showing Storm Slabs

30-50 cm of recent storm snow overlies a weak facetted layer in sheltered locations. As the snow settles into a slab, we suspect it will be reactive to human triggering. This problem will be most pronounced in areas with the most recent snow.

  • Use conservative route selection, choose moderate angled and supported terrain with low consequence.
  • The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Loose Dry

An icon showing Loose Dry

New snow and strong to extreme winds continue to produce loose dry avalanche activity throughout the forecast region. Give the recent snow some time to settle before exposing yourself to steep overhead terrain.

  • Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 1.5

Valid until: Feb 23rd, 2021 4:00PM