Avalanche Forecast

Issued: Jan 31st, 2021 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

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Strong winds are expected to continue to form fresh and reactive storm slabs, keeping avalanche danger elevated. Stick to simple terrain and avoid overhead hazard.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

SUNDAY NIGHT - Flurries, 5-10 cm / moderate to strong southwest wind / alpine low temperature near -4 

MONDAY - Flurries, 5-10 cm with another 15-25 cm overnight / moderate to strong southwest wind / alpine high temperature near -2 

TUESDAY - Flurries, 10 cm / moderate to strong southwest wind / alpine high temperature near -5 

WEDNESDAY - A mix of sun and cloud / light northwest wind / alpine high temperature near -7 

Avalanche Summary

Avalanche activity is expected on Monday with both natural and human triggered avalanches likely.

At the time of publishing, there were numerous size 1-1.5 human and explosives triggered storm slab avalanches reported on Sunday.

There were several size 1-2 natural, human, and explosives triggered avalanches reported in the region on Saturday.

Snowpack Summary

The Sea-to-Sky region has received between 30-60 cm since Saturday night, and it is expected to continue to pile up on Monday, with an additional 5-10 cm.

There is now about 30-70 cm of recent snow sitting on firm wind affected snow at upper elevations, on surface hoar in sheltered areas, on a melt-freeze crust below 1900 m, and on a sun crust on south-facing slopes.

A crust from early December may be found around 200 cm deep in the snowpack. In shallow rocky areas, recent test results suggest that it may still be possible to trigger this layer. In deeper snowpack areas it has shown no recent results and appears to be unreactive in these areas.

Terrain and Travel

  • Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
  • Avoid freshly wind loaded terrain features.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.

Problems

Storm Slabs

An icon showing Storm Slabs

By Monday afternoon there will likely be 30-70 cm of recent new snow, resulting in thick and reactive storm slabs. Human triggered avalanches will be likely throughout the day. Storm slabs may propagate widely as they sit atop a recently buried weak layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Feb 1st, 2021 4:00PM