Avalanche Forecast

Issued: Apr 2nd, 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 ldreier, Avalanche Canada

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Wind slabs may be found in lee terrain in the alpine and exposed treeline and will be most reactive where they overlie a crust. 

Summary

Confidence

High -

Weather Forecast

Saturday night: Mix of clouds and clear periods, trace of new snow, moderate southwest wind, alpine low -6 °C, freezing level at 700 m.

Sunday: Cloudy, up to 5 cm snow, moderate southwest wind, alpine high -4 °C, freezing level 1500 m.

Monday: Cloudy, 20-30 cm snow, moderate to strong southwest wind, alpine high -4 °C, freezing level at 1500 m. 

Tuesday: Cloudy, 10-15 cm snow, moderate to strong westerly wind, alpine high -5 °C, freezing level at 1500 m.

Avalanche Summary

On Friday, small natural dry loose avalanches were observed. A skier triggered cornice resulted in a size 2 avalanche. Skiers triggered a few small wind slab, storm slab and wet loose avalanches. 

On Thursday, numerous small size 1 wind slabs, dry loose, and wet loose avalanche activity were observed. 

On Wednesday, the region saw a natural cycle of wet loose, dry loose, wind slabs up to size 2, and wet slabs up to size 3. 

Snowpack Summary

20-40 cm of new snow overlies up to 20 cm of denser snow above 2000 m and tapers rapidly at lower elevations. 50-60 cm of snow sits over the mid-March interface at upper elevations. 

A melt-freeze crust exists on all aspects as high as 2000 m and to mountain top on solar aspects. Below the crust, the top 10-30 cm of the snowpack is moist.  

Westerly winds have formed reactive wind slabs on leeward terrain in the alpine and exposed treeline terrain.

The early-December rain crust is approximately a metre off the ground. Reports have recently indicated that large slab avalanches have failed on this interface earlier this week following a rain and warming event. This layer may be dormant now due to colder weather, however, it may appear again during the next big warm-up or with increased load from wind, snow and/or rain. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs may exist in lee terrain features in the alpine and treeline, formed by recent snowfall and westerly winds. These wind slabs will be most reactive where they overlie a slick crust.  

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 3rd, 2022 4:00PM