Avalanche Forecast

Storm slabs will increase in size and sensitivity as snow accumulates and winds ramp up. Expect thicker and more reactive slabs above 4500ft where precipitation should come as all snow. Carefully evaluate how new snow is bonding to itself and old snow surfaces. Avoid unsupported slopes and large terrain features steeper than 35 degrees, and be leery of any steep slopes with evidence of freshly wind-drifted snow. Watch for obvious signs of instability like shooting cracks, collapses, and recent avalanches. Seek out supported lower-angeled terrain away from overhead hazard.

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.

Loose wet avalanches are likely on Tuesday with fluctuating snow levels and rain on new snow. As wet avalanches run downslope, they could entrain large amounts of snow and even trigger slab avalanches. Look for roller balls and pinwheels as indicators of weakening snow surfaces. Avoid gullies and other confined terrain features where debris could pile up and increase the consequences of even a small avalanche. Stay off slopes steeper than 35 degrees where you find wet unconsolidated surface snow.

Release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. They generally move slowly, but can contain enough mass to cause significant damage to trees, cars or buildings. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

Travel when the snow surface is colder and stronger. Plan your trips to avoid crossing on or under very steep slopes in the afternoon. Move to colder, shadier slopes once the snow surface turns slushly. Avoid steep, sunlit slopes above terrain traps, cliffs areas and long sustained steep pitches.

Several loose wet avalanches, and lots of pinwheels and roller balls.

Loose wet avalanches occur where water is running through the snowpack, and release at or below the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.