Avalanche Forecast

Issued: Jan 4th, 2022 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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Storm and wind slabs may take some time to bond to the snowpack. Adopt a conservative mindset until there is clear evidence that the snowpack has stabilized.

Summary

Confidence

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

Weather Forecast

TUESDAY NIGHT: Mostly cloudy with snowfall, accumulation 5 cm, 15 km/h west wind, alpine temperature -12 C.

WEDNESDAY: Partly cloudy with no precipitation, 15 km/h southwest wind, alpine temperature -12 C.

THURSDAY: Cloudy with snowfall, accumulation 10 to 20 cm, 40 km/h southwest wind, alpine temperature -8 C.

FRIDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 30 km/h southwest wind, alpine temperature -7 C.

Avalanche Summary

A widespread avalanche cycle was observed within the storm snow on Sunday and Monday in the north of the region and potentially areas of the south. The likelihood of humans triggering the storm snow remains elevated.

Snowpack Summary

Around 40 to 70 cm of snow has accumulated since January 1. The snow has likely formed touchy storm slabs in sheltered terrain and wind slabs in exposed terrain from strong southerly wind.

The storm snow overlies various layers that formed during the cold spell in late December. These layers include a melt-freeze crust on sun-exposed aspects, weak and feathery surface hoar in areas sheltered from the wind, weak and sugary faceted grains, and hardened surfaces from strong wind. There is uncertainty in how long it will take for the storm snow to bond to these layers.

A weak layer of faceted grains may be found above a widespread melt-freeze crust that formed in early December. This layer is likely found anywhere from 80 to 200 cm deep. This layer was the culprit of large, destructive avalanches in December for the neighbouring Sea to Sky region. It has been most reactive between 1700 and 2100 m.

The lower snowpack is well-settled and strong.

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Make conservative terrain choices and avoid overhead hazard.
  • Be aware of the potential for large, destructive avalanches due to the presence of deeply buried weak layers.

Problems

Storm Slabs

An icon showing Storm Slabs

Storm and wind slabs that formed earlier this week may remain touchy to human traffic. Storm slabs are most likely found in terrain sheltered from the wind and wind slabs in exposed terrain features at higher elevations. These slabs sit on weak snow or hard surfaces that may take some time to bond.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

A weak layer of faceted grains above a hard melt-freeze crust may be found around 80 to 200 cm deep. This layer is most prominent between 1700 and 2100 m. All the recent snow has loaded this weak layer, increasing the likelihood of triggering it. Humans are most likely to trigger it where it is spatially shallow, for example in thin, rocky snowpack areas.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

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