Avalanche Forecast
Regions: Cascades - East.
Use caution near slopes 35 degrees and steeper especially above 5,000 feet. Give the snowpack another day to adjust before venturing into big terrain. Over the past 4 days, a storm brought snowfall and rain adding stress and new layers to the snow on the ground.
Discussion
Recent avalanches abound! While observations have been limited in this zone, observers in neighboring forecast areas near Stevens and Washington Passes have reported widespread avalanches, including some that were very large and dangerously surprising. Check out the Stevens Pass forecast if you are heading to areas near the Cascade Crest such as Icicle Creek, the Teanaway and Salmon la Sac drainages. If you are going into the northern portion of the zone, near Holden Village, expect conditions more similar to Washington Pass. Rain fell to between 4,500-5,000ft on Tuesday.
A very large avalanche (D2.5) with a deep crown just west of the East Central zone, on Rock Mountain, southeast, 6,000ft. 1/7/2020. Photo: Josh Hirshberg
Snowpack Discussion
New Regional Synopsis coming soon. We update the Regional Synopsis every Thursday at 6 pm.
Avalanche Problems
Storm Slabs
You may be 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. Avoid convex slopes and unsupported features. Use caution around slopes steeper than 35 degrees. Watch for stiffer snow, overlying softer snow. Use small test slopes and snowpack tests to look for recent storm layers in the top 1-2 feet of the snowpack.
In wind-exposed areas and especially in the Wenatchee Mountains you may encounter drifts on leeward sides of ridges at upper elevations. Avoid drifted features and leeward start zones. Suspect that older weak layers of snow could produce surprising avalanches if you find less than 4 feet of snow on the ground or if you are in the northern portion of the zone.
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.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 1