Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–2.5
Recent Avalanches: The last significant avalanche cycle was during the Thanksgiving storm, about 10 days ago. Since then, we have seen continued glide avalanche activity throughout the area.
The warm and wet weather last week didn't do any favors for the skiing and riding conditions, creating an icy crust up to about 2600'. However, now that the snowpack has refrozen, the silver lining is that the wet weather added a lot of strength to the snowpack. So we an not as concerned about buried weak layers at treeline elevations and below.
Above 2500', we are still concerned about several weak layers of buried surface hoar that range from 1 to 3' deep in the snowpack and have the potential to cause large human-triggered avalanches. Buried surface hoar is notorious for giving no signs of instability (no red flags) and remaining dangerous for a long time, which makes it very difficult to assess and manage. To avoid the potential for being involved with one of these avalanches, you can always stick to simple, low angle terrain and avoid travelling above terrain traps like gullies, trees, or cliffs.
Wind Slabs: Elevated winds averaging 10 to 15 mph with gusts up to 35 mph from the North or Northeast in some portions of the forecast area could build wind slabs up to 1' deep. These typically form along ridgelines and convex rolls where wind transported snow accumulates. To identify areas harboring wind slabs, you can look for active wind loading, shooting cracks, and hollow sounding pillows of new snow. Triggering a smaller wind slab could cause a larger avalanche on a buried weak layer.
