Avalanche Forecast

The avalanche issue you deal with Thursday will blur the line between storm and wind slab. The winds definitely blew strong enough to transport snow during the storm. However, temperatures fluctuated, intense precipitation occurred, and we’ve continued to receive more snow. Even though the avalanche problem doesn’t fit into a clean box, the solution is simple. When you find more than 8 inches of up-side-down storm snow or notice the wind drifted snow into thicker slabs, stay off of slopes greater than 35 degrees. Because higher elevations picked-up more snow, expect avalanches to be easier to trigger and larger as you ascend. If you find storm slabs low in the terrain, be confident they exist higher and will only be larger and more difficult to manage. 

Release of a soft cohesive layer (a slab) of new snow that breaks within the storm snow or on the old snow surface. Storm-slab problems typically last between a few hours and few days. Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

You can reduce your risk from Storm Slabs by waiting a day or two after a storm before venturing into steep terrain. Storm slabs are most dangerous on slopes with terrain traps, such as timber, gullies, over cliffs, or terrain features that make it difficult for a rider to escape off the side.

Storm slabs usually stabilize within a few days, and release at or below the trigger point. They exist throughout the terrain, and can be avoided by waiting for the storm snow to stabilize.