Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 2–3
Since just before Valentine's Day we have added 20+ inches of new snow over a very concerning snowpack structure. This is important to note because we didn't see much feedback from the initial 12 inches of snow that fell on Feb 14 which makes us worried that we are crossing the threshold for what these weak layers have been capable of withstanding. Avalanches that fail on these buried weak layers will be large and unsurvivable. In most cases, it will likely take the majority of the season's snowpack with it. With additional snowfall in the forecast today it's smart to give this problem a wide berth and avoid being on, connected to, or underneath slopes greater than 30 degrees. Natural avalanches are possible today.
Our overall snowpack depth is all over the place. The areas to be aware of are areas where the snowpack is thinnest. We're talking about near and below treeline and previous slopes that have avalanched. Shallower snowpacks will harbor more advanced facets and will be easier to trigger as a skier or rider. Areas of deeper snowpacks will be a bit more stubborn but if triggered will produce a very large unsurvivable avalanche. Look for shooting cracks and collapses to indicate the presence of this instability.
As always during times of uncertainty and high consequence, we can limit our exposure with our terrain selection. Sticking to terrain no greater than 30 degrees and staying out from underneath large open terrain will help mitigate your exposure to increasing the avalanche danger.
Multiple faceted weak layers exist in the snowpack, with some closer to the surface. The weak faceted snow closer to the ground continues to remain a concern.