Avalanche Forecast
Regions: Olympics.
Dangerous avalanche conditions are expected Sunday night and Monday and travel in avalanche terrain near and above treeline is not recommended.
Detailed Forecast
Moderate to heavy rain should reach up into the above treeline elevation band through Monday. This will orient the avalanche type toward wet slab and wet loose. Rain should quickly load snowfall received earlier in the storm and result in widespread natural loose wet avalanches especially in steeper terrain. Natural wet slabs, mainly on lee aspects near and above treeline, have the potential to be larger and more destructive. Due to low snow cover, the avalanche danger will quickly decrease in the below treeline band at lower elevations.Â
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Snowpack Discussion
On Saturday, NWAC pro-observer Katy Reid confirmed a 3 cm graupel layer at 10 cm below the surface on E-NE aspects near and below treeline. This layer could become reactive during the upcoming storm. Otherwise, the Hurricane Ridge area did not have many concerns heading into the weekend storm.Â
On Sunday light snow accumulated at Hurricane Ridge with rising temperatures and strong south transport winds leading to inverted new snow layering and new wind slab. Snow turned to rain at Hurricane Ridge late Sunday afternoon. Moderate to heavy rain should continue Sunday night.Â
Avalanche Problems
Wet Slabs
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.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 1
Loose Wet
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.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 1