Avalanche Forecast

Mid-march sunshine and warm temperatures are affecting a large swath of the compass during this dry and mild stretch, i.e. it’s not just steep southerly aspects these days. As the day progresses and temperatures warm, monitor changes in the upper snowpack, looking for natural pinwheels or small loose wet avalanches as clear signs of increasing danger.

As the loose wet hazard increases, change your aspect and avoid similar slopes. Be especially cognizant of the consequences of even small avalanche around terrain traps like gullies or cliff bands.

We have removed this problem from the above treeline terrain because winds have been preventing melt from occurring.

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.

Is there enough meltwater entering the snowpack for a wet slab avalanche to occur? We don't know. We do know another day of sunshine and above freezing temperatures will increase the likelihood of this dangerous avalanche problem.

You will want to steer clear of parts of the mountain that don't see the cooling effects of moderate east winds (think wind sheltered canyons for example). Large and dangerous avalanches may occur in isolated areas during Moderate danger.

You may not see direct signs of instability prior to a wet slab release. As the day progresses, deal with the uncertainty surrounding this dangerous and hard to predict avalanche problem by avoiding terrain where avalanches can start, and limit your exposure to where avalanches can run or stop.

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.