Persistent Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Recent Avalanches: The most recent reported avalanches were on the west side of Seattle Creek last weekend. These were likely wind slabs failing on weak, faceted snow.
It's the winter solstice today, which at Turnagain Pass means we have a whopping 5 hrs and 37 min to get out and enjoy the variety of snow textures the past two weeks of cold, clear, windy weather has brought us. Our main avalanche concern is the weak layer of sugary, faceted snow that has formed during this dry spell, and is buried by stiff, windblown snow in the upper elevations.
This setup may give warning signs like shooting cracks or collapsing, but it will not always give you clear feedback when conditions are dangerous. Expect to find the most unstable conditions in steep terrain just below ridgelines, convex rolls, and in gullies. These stiff and stubborn wind slabs have a dangerous potential to allow a person to travel well out onto a slope before triggering an avalanche that propagates well above them. While we do not expect to see any natural avalanches today, it will be important to identify and avoid any slopes that have a stiff wind slab on the surface.
(12/18/2025)
The layers of buried surface hoar have gone dormant, but that weak, faceted snow near the surface may still produce large avalanches where it is capped by a stiff wind slab. Photo from a snowpit on Magnum Ridge last week.
Photo: Marc Heifetz