Avalanche Forecast

A forecast convergence zone set in the Mountain Loop area late Sunday night will produce more widespread avalanche activity. All the recent light, fluffy, unconsolidated snow will eventually form a slab as incremental loading continues to add weight. 6-10” of expected storm snow will fall on an estimated 6-12” of low-density storm snow that fell Friday afternoon through Saturday night. These snow layers rest above older faceted snow, which will eventually fail under stress of incremental loading patterns. Watch for wind-affected snow which may also form a slab. Storm slabs can be avoided by sticking to low angle supported slopes. Cracking or whumphing of the snow is a valuable warning sign that anticipated problems are in your terrain.

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.