Avalanche Forecast

Northwest wind has formed fresh drifts on leeward sides of ridges at the middle and upper elevations in the past 24 hours. There are also slightly older wind slabs from January 6th and 7th. Many leeward start zones have deep crowns from avalanches earlier in the week. Avoid deeply drifted features and leeward start zones. Even slopes that have avalanched once could slide again. The most dangerous slopes are at the highest elevations. 

Release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.

Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..

Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.

Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.

You may be still able to trigger avalanches where recent snow has accumulated in the past 24 hours or where you find lingering storm layers from the past couple of days. Use caution on steep, convex slopes and unsupported features. You can find an interface of stiffer snow sitting on softer storm snow about 2-3 feet below the snow surface. Use small test slopes and snowpack tests to look for recent storm layers in the top 2 feet of the snowpack.

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.