- Date
- jeudi 13 mars 2025
- Auteur
- Tyson Rettie, Avalanche Forecaster
- Étiqueté sous
Winter isn’t over yet. Most of our regions saw significant snowfall last weekend, with an average of 50 cm in 48 hours for the interior and over 1 meter for the south coast. After those storms, the taps stayed on with another 20 to 40 cm arriving mid week. Both of these systems came in warm, with strong southerly winds, and the result was some impressive, widespread avalanche activity.
Natural storm slab avalanche activity was widespread last weekend. Credit: VARDA
For most regions, we will see a break in the weather for Friday, but active weather is coming in right behind it for western Canada—although we are uncertain about the timing and intensity of this storm. This will mean there is all the more reason to keep an eye on our forecasts and be sure to double check again in the morning before heading into the mountains. In times of uncertainty, we may make last minute updates with the most current information available.
Precipitation forecast for Thursday afternoon through Sunday afternoon shows substantial amounts for the coastal regions and the southern interior. Source: Environment Canada
As well as the storm and wind slab problems caused by the recent snow, we also have concerns about the snowpack structure. The layer that’s on our minds most at the moment is the early-March crust/surface hoar layer. This layer is found around 50 to 70 cm deep in most regions in western Canada, but over 1 meter on the south coast and parts of the Selkirks. This means it has the potential for producing very large avalanches and it has already been responsible for many avalanches up to size 3.5. We suspect this layer will remain a concern for the near future, especially in the interior.
With a variety of weak layers in the snowpack, remotely triggered avalanches remain possible like this one that was triggered from 200 m away in the White Pass area last Sunday. Credit: MIN User karla
The recent storm snow has a poor bond to the old snow surface in many areas. Storm slabs remain a major concern for human triggering in many regions. Credit: North Rockies Field Team MIN
In regions with a shallower snowpack, such as in the East Purcells, Rockies, and inland side of the northwest coast, we still have concerns with weak layers from mid-February and late-January. Despite these regions potentially seeing less active weather this weekend, strong solar input could be a driver of hazard and may wake these layers up.
Old weak layers from January and February remain reactive in some areas. Credit: South Rockies Field Team MIN
Spring can be a challenging time due to the mixed bag of conditions you may find in the mountains. The weather is dynamic and less predictable, making it more difficult to forecast and potentially highly variable throughout the day. More than ever, you need to keep your head up and verify conditions as you move through terrain. Hazard can change quickly, even from aspect to aspect and hour to hour.
Get the forecast so you can know more, go further, and take advantage of all the deep pow out there more safely.