Avalanche Forecast

Issued: Jan 13th, 2022 4:00PM

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

Avalanche Canada rbuhler, Avalanche Canada

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Hazard will likely depend on the extent of cooling and new crust formation Thursday overnight. Storm slabs are expected to remain touchy up high where the snow remains dry, especially in wind loaded terrain. 

Summary

Confidence

Moderate - Uncertainty is due to rapidly fluctuating freezing levels.

Weather Forecast

Unsettled conditions are expected for Friday with a ridge of high pressure to the south and a weak storm system approaching from the west. 

Thursday night: Partly cloudy, moderate SW wind becoming strong by early morning, freezing levels may linger at around 2000-2500 m with a temperature inversion and below freezing temperatures in the valleys. 

Friday: Mainly cloudy with periods of light flurries, strong SW wind, freezing levels around 1500 m. 

Friday night and Saturday: Snowfall up to 25 cm, strong SW wind, freezing levels around 1500 m.

Sunday: Snowfall, moderate to strong SW wind, freezing levels around 1000 m.

Avalanche Summary

On Wednesday, skiers were triggered three size 1-1.5 storm and wind slabs between 1700 and 2000 m. These slabs were 20-50 cm thick. No new avalanches were reported on Tuesday but observations were limited. 

On Friday, the avalanche hazard is uncertain and will likely depend on the extent and thickness of a new surface crust. Where the skies are clear and the freezing levels drop substantially, a thick crust and lower hazard can be expected. Storm slabs will remain a concern at higher elevations, especially in wind loaded terrain. 

Snowpack Summary

On Thursday, freezing levels climbed into the alpine in the south of the region and to at least treeline in the north. With temperatures expected to drop on Thursday night, a widespread surface crust is expected to form. Below the new crust, 30-50 cm of recent storm snow has been settling rapidly with the mild temperatures. This snow overlies a previously wind-affected surface comprised of old hard wind slabs, sastrugi, and areas stripped back to the ground or old crusts. Snow at this interface was significantly weakened during the cold snap, which means the bond here remains in question. 

The early-December crust/facet interface can typically be found down 50-150 cm but has been dormant recently and is no longer expected to be creating an avalanche problem in the region. The base of the snowpack is composed of crusts and weak faceted grains, particularly in thin snowpack areas east of the divide. 

Terrain and Travel

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Be alert to conditions that change with elevation.
  • The more the snow feels like a slurpy, the more likely loose wet avalanches will become.

Problems

Storm Slabs

An icon showing Storm Slabs

A reactive storm slab should be expected where the snow surface remains dry and crust-free at higher elevations. They will be most reactive in wind loaded terrain. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

At lower elevations where the snow surface remains moist or wet, human triggered wet loose avalanches remain possible on steep slopes. 

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 14th, 2022 4:00PM