Avalanche Forecast

Issued: Apr 12th, 2023 2:30PM

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

Avalanche Canada mkoppang, Avalanche Canada

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The avalanche cycle is slowing as temperatures cool. Watch for fresh windslabs in alpine terrain. Skiing is challenging in lower elevations due to the crust from rain earlier in the week.

Summary

Confidence

Moderate

Avalanche Summary

Avalanche activity began to slow today with no new avalanches noted. Evidence of the cycle from the past few days is widepsread with many slides either failing at the ground or at the persistent weak layer down 1m.

Snowpack Summary

Cooler temperatures have helped stabilize the snowpack where previously it lacked structure and was rain soaked. This is mainly below 2200m or just below treeline. Above this elevation the snow was drier and windslabs formed with the strong SW flow. These windslabs are overlying a variety of different surfaces from crusts on solar aspects to dry snow on more polar. Carefully evaluate this bond as you travel. A deeper persistent layer down 1m was active in many avalanches over the past few days. This layer was most active on N and E aspects. Treat any area that have not slid as suspect and requires careful evaluation or imply avoidance. Deeper in the snowpack the weak facets and depth hoar at the base of the snowpack is still there. As temps warm up and this layer begins to settle and squish out it will improve and begin to bond but for now, its still a layer to think about as you travel. Thin areas is where you may be able to trigger this weakness.

Weather Summary

Generally light winds on Thursday with trace accumulations of snow. Temperatures will remain cool with the freezing level forecasted to be around 1800m. If the sun comes out solar radiation can be intense at this time of year so pay close attention to cloud cover.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Windslabs in the recent storm snow should be expected at treeline and above. Evaluate the bond with the underlying snowpack which is highly variable. There is lots of uncertainty at this interface currently.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

The persistent layer down 1m has been active due to recent snow loads.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Rain at lower elevations and heavy snow at upper elevations have woken up this layer. Avoid avalanche terrain,

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3.5

Valid until: Apr 14th, 2023 4:00PM

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