Avalanche Forecast

Avoid terrain where avalanches may start, run, or stop. Very large natural avalanches may run long distances. Stay out of canyons and valley bottoms where avalanches may reach from open slopes above. 

A cycle of large avalanches is very likely tonight as rain saturates the recent snow above a crust formed by warm weather over MLK weekend. Dry snow, containing a variety of weak layers exists under this melt-freeze crust. If rain penetrates the crust, the potential for very large and destructive avalanches exists.

Release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slab avalanches can be very destructive.

Avoid terrain where and when you suspect Wet Slab avalanche activity. Give yourself a wide safety buffer to handle the uncertainty

A Wet Slab avalanche. In this avalanche, the meltwater pooled above a dusty layer of snow. Note all the smaller wet loose avalanches to either side.

Wet slabs occur when there is liquid water in the snowpack, and can release during the first few days of a warming period. Travel early in the day and avoiding avalanche paths when you see pinwheels, roller balls, loose wet avalanches, and during rain-on-snow events.

Many natural wet loose avalanches will occur Wednesday night, but rain will continue to weaken the snow surface and loose avalanches will be easy to trigger on Thursday. Loose wet slides may run faster and further than typical because of the firm MLK weekend melt freeze crust under recent snow. Avoid steep and unsupported slopes especially near creeks, cliffs and other terrain traps. Remember that loose wet avalanches are often surprisingly powerful and being caught in even a small on can be dangerous.

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.