Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Very Likely
- Größe
- 1.5–2
You're very likely to trigger 1-3' thick slab avalanches at middle and upper elevations. The size and likelihood of avalanches will increase as you climb into areas more exposed to the wind.
Obvious large cornices, dunes, or blowing snow this afternoon will clue you in to where conditions are at their worst, but unfortunately, avoiding this problem is not so simple. Yesterday, recent natural avalanches and many snowplow-triggered avalanches were reported near Galena Summit. Similar slides were observed in the Headwaters of the Salmon (photo at right/below). These avalanches released in subtly wind-affected areas or those that were mostly sheltered from the wind.
Recent storm snow is perched precariously atop well-developed weak layers, including facets, facet + crust combinations, and surface hoar. All steep slopes are suspect. Cracks shooting out from your skis or boards clearly indicate instability. Avalanches can be triggered remotely and break wider than expected.
These smaller Persistent Slab avalanches could "step down", triggering the much larger Persistent Slab avalanches described below.
(1/10/2024) These persistent slab avalanches released in obviously wind-loaded and mostly sheltered terrain. Headwaters of the Salmon River, N/NE facing slopes. Photo: Carl Rixon