Date of Observation: 02/10/2023
Name: Evan Ross and Zach Guy
Zone: Northwest Mountains
Route Description: Ruby Peak area, traveling on south to east aspects near and above treeline.
Observed avalanche activity: Yes
Avalanches: Skier and snowmobile triggered a handful of small wind slabs on drifted features near treeline. Crowns ranged from 4″ to 12″ thick. They were stiff enough to break above you (generally 4F, some pockets of 1F).
Weather: Light northerly winds with no transport. Warming temps, clear skies.
Snowpack: Surfaces near and above treeline are wind affected by the recent wind event. Wind slab formation is fairly easy to identify; most terrain is soft, rippled sastrugi posing no hazard, while concave terrain features and steep rollovers have stiffer, smoother pockets of drifted snow that were sensitive to ski and snowmobile cuts. Observed some rollerballs on sunny aspects, but were back at the trailhead mid-day before things warmed up too much.
Photos:-
- Small skier triggered wind slab on south Ruby.
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- A couple of small snowmobile triggered wind slabs. East 11,200ft.
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- South side of Mt Owen. The concave terrain features looked the most suspect for lingering wind slabs.
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- E-NE Mt Owen. Lingering wind slabs looked to primarily be located in concave terrain features and lower on the slope then typical.
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- Wind texture in the alpine will help decrease the number of loose wet avalanches during the warmup.
