Avalanche Forecast

Issued: Apr 8th, 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 Cornices.

Avalanche Canada ghelgeson, Avalanche Canada

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Fresh storm slabs are expected to remain sensitive to human triggering this weekend, especially in wind loaded terrain. Start on smaller terrain features and gather information before committing to bigger terrain.

Summary

Confidence

Moderate - Uncertainty is due to field data and reports showing a wide variation in conditions throughout the region.

Weather Forecast

FRIDAY NIGHT: 2 to 6 cm of snow, moderate west wind, freezing level near valley bottom.

SATURDAY: Broken cloud cover, no significant precipitation expected, moderate north/northwest wind, freezing level beginning near valley bottom, rising to around 800 m.  

SUNDAY: Broken cloud cover in the morning giving way to scattered cloud cover in the afternoon, no significant precipitation expected, light northeast wind, freezing level beginning near valley bottom, rising to around 1200 m in the afternoon. 

MONDAY: Clear skies at dawn with cloud cover increasing to broken after lunch, potential for some light flurries/rain in the afternoon, moderate south wind, freezing level beginning near valley bottom, rising to around 1000 m in the afternoon. 

Avalanche Summary

Observations were a bit thin on Thursday, but this MIN sums it up very well. Up to 50 cm of new snow producing audible avalanches in big terrain, and smaller storm slabs in more moderate terrain.

On Wednesday, a few large wind slabs up to size 3 as well as several storm slabs to size 2 were triggered with explosives. Several small natural dry loose avalanches were reported, as well as a large (size 2.5) cornice failure. Skiers triggered several small wind slab avalanches in the alpine. 

Snowpack Summary

20-50 cm of new snow adds to the 30-60 cm of recent snow, which overlies a hard melt-freeze crust. The previous snow surface was wind affected and in some wind-exposed areas the wind had scoured the snow down to the crust. 

Around 100 cm down, a layer of weak snow (facets or surface hoar) has been occasionally reported in sheltered areas. The distribution of this layer has been reported as isolated and is likely not a problem in many areas.

Cornices are very large and exposure to them should be minimized, especially during warm or windy weather.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Keep in mind the crust offers an excellent bed surface for avalanches.
  • Even brief periods of direct sun could produce natural avalanches.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Problems

Storm Slabs

An icon showing Storm Slabs

20 to 50 cm of recent snow accompanied by moderate to strong south and west wind has formed storm slabs that will likely remain reactive to human triggering this weekend.

If the sun comes out, the potential for wet loose avalanches will increase, especially on steep sun-exposed slopes. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Cornices

An icon showing Cornices

New snow and wind have added additional load to the already large cornices and might lead to cornice failures. Minimize overhead hazard and give cornices a wide berth when travelling on ridgetops.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3.5

Valid until: Apr 9th, 2022 4:00PM