Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–2.5
On many slopes, the snow is still ripe for triggering 2-4ft deep avalanches above a crust. Consider avoiding slopes and staying well out from underneath slopes steeper than 35 degrees. Give larger terrain features wider safety margins than you usually would. At lower elevations, we don't have enough slab over the weak layer for this to be a consistent problem.
On Tuesday, at least a couple of recent large avalanches were reported around the Blewett Pass area. Also on Tuesday, a skier was partially buried in an avalanche on a NW aspect of Jim Hill in the neighboring Stevens Pass zone. These avalanches are failing 2-4ft deep, propagating widely, and being remotely triggered from low-angle terrain below or adjacent to steep slopes. You might not receive signs of instability before the whole slope fails. It could be the 2nd, 3rd, or 8th person on the slope that triggers it.
(3/6/2024)
Large slab avalanche off a steep east facing feature in Owl Creek near Blewett Pass.
Photo: Tony Stewart