Avalanche Forecast

Issued: Mar 3rd, 2020 4:00PM

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

Parks Canada William Lawson, Parks Canada

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More snow and wind will heighten the avalanche danger in the region. Avoid travel in wind loaded areas and limit your exposure to overhead hazard.

Large avalanches at upper elevations can reach terrain below tree line.

Summary

Weather Forecast

Forecasted snow for Tuesday night varies from 5-30cm through the region. This pulse of snow will be accompanied by strong Westerly winds. The snow will end midday Wednesday with a short lived clearing trend Thursday. Another system will move into the region late Thursday with more snow on the way.

Snowpack Summary

20-30cm of new snow and Strong to Extreme SW continue to form wind slab at tree line and above. Watch for buried sun crust on steep solar aspects. In thin snow pack areas a dense mid-pack sits over a weak, faceted base. Thick snowpack areas have a denser base with few weaknesses.

Avalanche Summary

No new natural avalanches observed Tuesday. Ski hills reported continued wind slab development at alpine and tree line elevations. Explosive control produced avalanches to size 1 on this new wind slab. With more snow and wind forecasted Tuesday night we will likely see continued slab development at upper elevations.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

More snow and wind will add to the wind slab problem at tree line and above. As the problem develops we will likely see natural avalanches release out of steep leeward terrain.

  • Be careful with wind loaded pockets while approaching and climbing ice routes.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Avalanche activity on the basal facets has slowed down but the weakness in the snowpack remains a concern. These are hard to predict, but are most likely in areas with a thin snowpack (<130cm) where the basal facets and depth hoar are prominent.

  • Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
  • Use caution in thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Mar 4th, 2020 4:00PM