Avalanche Forecast

Another day of cool temperatures and partly sunny skies will allow the Avalanche danger to slowly decrease as stiff wind slabs slowly begin to heal on Sunday. You may still trigger a wind slab on steep slopes near ridgeline. You are more likely to trigger a wind slab in areas where you observe indications of wind-deposited snow including snow pillows or drifts, chalky/firm snow, or cornices. These visual clues allow you to identify and avoid lee aspects, convex rollovers, and steep unsupported slopes are where you are most likely to trigger a Wind Slab on Sunday.

While it is not listed as an avalanche problem, on polar aspects in wind-sheltered terrain, it may still be possible to trigger a small Loose Dry avalanche on slopes steeper than 35 degrees.

Around 10 inches of new snow has accumulated in the Hurricane Ridge area as of Friday afternoon. Moderate to strong southerly winds redistributed the new snow forming wind slabs on northerly aspects near and above treeline and stripping snow off of exposed southerly aspects. The wind slabs continued to be reactive on Saturday near ridge-crest and were becoming stiffer and more easily triggered.

While north-facing slopes continue to remain soft, ample sunshine on Sunday with temperatures getting into the mid-30's at Hurricane Ridge added to the melt-freeze crust already present Saturday morning on solar aspects.

In sheltered areas generally loose surface conditions exist. This resulted in three small loose dry avalanches Thursday.

The new snow sits on a variety of old snow surfaces. On slopes that received direct sun during the recent clear weather, a firm and thick melt-freeze crust can be found. On shaded slopes a thinner more breakable crust has been observed.

Weaker layers of sugary facets and thin crusts have been found within the snowpack. Current observations suggest that these weak layers are not widespread. You are most likely to find older weak snow on East facing slopes about 1 ft (30cm) below the snow surface.

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

Observations

On Saturday, NPS rangers reported a small skier-triggered wind slab (40 ft wide, running 80 ft) wide on a north-facing aspect. North-facing aspects preserved soft snow.

Chalky-textured wind-loaded pillow near ridge-line adjacent to the skier-triggered wind slab. Photo credit: Sarah Crosiers, Hurricane Ridge NPS

NWAC observer and NPS rangers on Thursday, 3/22 found blowing snow actively building fresh cornices and wind slabs above 5000’. Slabs were generally shallow (6-8”, 15-20cm) but were observed upto 1 foot (30cm) thick. Exposed windward slopes were often stripped of the new snow down to a firm and hardening crust.