Avalanche Forecast

Issued: Apr 17th, 2023 4:00PM

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

Avalanche Canada Mikey, Avalanche Canada


Approach the alpine with caution. This is the season to start early and finish early to maximize easy travel and limit your exposure to sun baked slopes.




Avalanche Summary

No new avalanches observed or reported, But evidence is easily visible as you drive through the valleys.

Snowpack Summary

Up to 10cm of snow has fallen on Monday with extreme Westerly winds so expect a new crop of wind slabs. Depending on temperature and cloud cover, solar aspects are primarily crusty in the morning and becoming moist with daytime heating and radiation. Travel at lower elevations is fast and easy in the mornings on a thick melt-freeze crust from the rain last week. Forecasters continue to track persistent weaknesses down anywhere from 40 to 100cm on polar aspects. These weaknesses are highly variable in nature and travelers should take the time to dig down and evaluate the snowpack frequently. Also, the lingering deep persistent slab problem is still alive and well. The deep weak layer of facets and depth hoar have become quite active in the increased heat, and this is expected to continue, with large destructive avalanches possible.

Solar radiation has a big influence on stability at this time of year. Stability will quickly deteriorate on solar aspects as temperatures warm up. These decreases will be most apparent on steep solar aspects, especially in thin rocky terrain. Early starts and finishes that avoid the heat of the day are key. Also pay close attention to what aspect you are on or under, and be mindful of cornices.

Weather Summary

We are in Spring and the weather is getting challenging to forecast. Models are showing 5-15cm of snow for Tuesday. Temperatures will be cool in the morning at around -11c and warm up to -3c. Winds are expected to be moderate from the SE and changing to Westerly in the evening. Expect mostly cloudy skies but do not be surprised if the sun pokes out.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Cornices become weak with daytime heating or solar exposure.


Wind Slabs

An icon showing Wind Slabs

Wind slabs in the recent storm snow should be expected at open treeline features and above. Evaluate the bond with the underlying snowpack which is highly variable. There is currently a lot of uncertainty with the characteristics of this interface.

Aspects: All aspects.

Elevations: Alpine.



Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

The persistent layer down 100cm has been active due to recent snow loads. It also appears to be sensitive to heat.

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

Elevations: Alpine, Treeline.



Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Shallow snowpack areas are an area of special concern, especially with intense solar radiation and/or daytime heating.

Great evidence of this problem avalanching is easy to find along the spray road right now.

Aspects: All aspects.

Elevations: Alpine, Treeline.


Possible - Likely

Expected Size

2 - 3.5

Valid until: Apr 18th, 2023 4:00PM