Avalanche Forecast

Issued: Jan 4th, 2022 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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Triggering large avalanches remains likely. The snowpack will need some time to gain strength.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

TUESDAY NIGHT: Partly cloudy with no precipitation, 10 km/h west wind, treeline temperature -6 C.

WEDNESDAY: Increasing clouds with late evening precipitation, 10 km/h southwest wind, treeline temperature -6 C.

THURSDAY: Cloudy with snowfall, accumulation 20 to 30 cm, 50 km/h southwest wind, treeline temperature -2 C, freezing level rising to 1200 m.

FRIDAY: Early-morning snowfall then clearing skies, accumulation 5 cm, 40 km/h west wind, treeline temperature -5 C.

Avalanche Summary

We received reports of many natural and human-triggered avalanches on Monday and Tuesday (e.g., here, here, here, and here). They all occurred within the recent 100+ cm of storm snow, with some propagating far, on the layers described in the Snowpack Summary.

We'd appreciate any observations while you are out travelling on the Mountain Information Network.

Snowpack Summary

Over 130 cm of snow has accumulated since January 1. The snow has formed touchy storm slabs in sheltered terrain and wind slabs in exposed terrain near the mountain tops.

The storm snow overlies various layers. These layers include a hard melt-freeze crust or ice layer at lower elevations and on sun-exposed slopes at higher elevations, weak and feathery surface hoar in areas sheltered from the wind, and weak and sugary faceted grains that formed during December's cold spell. There is uncertainty in how long it will take for the storm snow to bond to these layers.

The middle and base of the snowpack are strong, consisting of well-bonded snow and a few hard melt-freeze crusts.

Terrain and Travel

  • Use increased caution at all elevations. Storm snow is forming touchy slabs.
  • Give the new snow time to settle and stabilize before pushing into bigger terrain.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.

Problems

Storm Slabs

An icon showing Storm Slabs

Storm snow totals have exceeded 100 cm since the weekend, which has formed touchy storm slabs. Wind slabs may be found in lee terrain features near ridges, as the snow fell with strong wind from the south. These slabs may take some time to stabilize, as they sit on various smooth and/or weak layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Jan 5th, 2022 4:00PM