Avalanche Forecast

Issued: Jan 5th, 2022 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada zryan, Avalanche Canada

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The best riding and lowest hazard exist in sheltered areas at treeline and below.

Remember that days are short and temperatures are cold! Keep your objectives conservative and close to home.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations. Uncertainty is due to the extreme variability of wind effect on the snowpack.

Weather Forecast

Wednesday Overnight: Mainly clear. Light northerly winds with alpine temperatures around -35 C. 

Thursday: Mainly cloudy with light winds shifting to the southeast. Light flurries in the late afternoon and into the evening. Alpine temperatures rising to around -24 C.

Friday: Mainly cloudy with flurries. Light to moderate northeast winds, increasing in the afternoon and shifting northwest. Alpine temperatures around -25 C.

Saturday: Partially cloudy with light flurries, trace to 5 cm of accumulation. Moderate to strong southwest winds, alpine temperatures rising to -20 C.

Avalanche Summary

On Tuesday, Operators north of McBride reported two size two natural wind slabs. These slabs where a result of northeasterly outflow wind loading and occurred either on Monday night of Tuesday during the day.

Snowpack Summary

Recently formed wind slabs are most likely to be found on south and westerly aspects, but older wind slabs may be found on all aspects.

Recently formed wind slabs may remain reactive to human triggers for longer than is typical due to the weak facets (sugary snow) they are sitting on.

A crust that was formed at treeline elevations and below in early December has been reported in parts of this region. It can be found down 50-100 cm. There have been no recent reports of avalanches on this layer. A large amount of new snow or warming temperatures have the potential to cause large avalanches on this layer.

The base of the snowpack is composed of crusts and weak faceted grains, particularly in thin snowpack areas east of the divide. 

Avalanches on both of these weak layers can be best managed by avoiding likely trigger spots such as steep, rocky slopes, with a shallow or thin to thick snowpack.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Be aware of highly variable recent wind loading patterns.
  • The best and safest riding will be on slopes that have soft snow without any slab properties.
  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
  • Keep your guard up at lower elevations. Wind slab formation has been extensive.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent strong northeasterly winds have likely formed reactive wind slabs on lee features at all elevations.

Recently formed wind slabs are most likely to be found on south and westerly aspects, but older wind slabs may be found on all aspects.

Wind slabs may remain reactive to human triggers for longer than is typical due to the weak facets (sugary snow) they are sitting on.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Jan 6th, 2022 4:00PM