Avalanche Forecast

An incoming frontal system will bring light snowfall, increasing winds and much colder temperatures to the Olympics on Sunday. 

By Sunday afternoon you may be able to trigger fresh and shallow Wind Slabs near and above treeline in the Hurricane Ridge area, especially on NW-N-E-SE aspects. Fresh Wind Slabs may form quickly on the leeward side of terrain features and ridges near and above treeline. Use visual clues such as snow drifts, cornices, wind textured snow, and firm snow surface conditions that produce cracks to identify and avoid wind loaded areas.

You may be able to trigger Persistent Slabs on shaded slopes at mid to upper elevations. Persistent Slabs are difficult to manage and can break in surprising ways. To stay safe, avoid where the problem exists. Make sure to avoid avalanche terrain where new Wind Slabs and older Persistent Slabs likely overlap, such as N-E aspects near and above treeline. 

New snowfall will likely not be heavy enough to produce Storm Slabs in non-wind affected terrain. Anticipate a potential Storm Slab problem if more than 6-8 inches of snow accumulates in wind-sheltered terrain by Sunday afternoon. Cloudy and cool conditions will bring about an end to wet snow avalanche concerns.  

Temperatures have warmed over the last several days with mild daytime temperatures. Very little snowfall has accumulated in the past week. This has allowed for snowpack settlement and the development of a strengthening melt freeze crust.  

Slab avalanches likely released early last week, likely failing on a weak layer above a strong melt-freeze crust buried about 1.5 ft on lee slopes above Hurricane Ridge. This layer has been tracked over the past few weeks but has now produced at least two slab avalanches, each with crown depths about 1.5 ft and propagating over 100 ft wide on NE aspects between 5200-5400 ft. 

There are no other significant layers of concern in the snowpack at this time.

Observations

No new avalanche activity was reported in the Hurricane Ridge area Saturday. 

On Friday, NPS Rangers performed snowpack tests on a NNE aspect at 5,000 ft. They reported test results indicating propagation on a layer of weak old snow about 2 ft below the surface.

On Thursday, 3/29 NWAC professional observer Matt Schonwald saw evidence of two recent slab avalanches releasing on steep convexities on NE aspects between 5200-5400 ft. These avalanches released on a weak layer, poorly bonded to a hard crust. Several snowpack tests on this layer confirmed the propensity for avalanches to propagate.