Virginia Lakes, Morning winds, Snowpack Tests on Weak Layers

Submission Info
Saturday, January 27, 2018 - 11:15am
Red Flags: 
Recent loading by new snow, wind, or rain
38° 2' 38.4" N, 119° 15' 7.2" W
Snowpit Observations
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Skied the saddle between South Peak and Mt. Olsen to test any lingering sensitivity of older wind slabs and to test the buried weak layers. All morning moderate to stong N-E winds were stripping the tops of N facing slopes but were also cross-loading the sidewalls of gullies and the down wind sides of treed areas (see wind video). New wind slabs were between 1cm and 10cm thick in isolated areas (down wind of fetches that still had soft enough snow, and on slopes that were not bare from previous W wind stripping). Some localize cracking on kick turns and hand shears failed easy to moderate force under these newer deposits. Tested some SW facing slopes after about an hour or two of wind loading with not much in the way of results (see stomping video). Air temp was warm: 32 degrees F at 11am on a N facing slope.

Dug a test profile at 10,000' on a NNW facing 23 degree slope at 1120am to test the buried facets (see attached profile). Tests indicated some potential for fracture initiation but not propagation. Several other compression tests were performed thoughout the day with inconslusive results. The facets buried in our area did fail on the ground in several tests. Snow depths ranged from 45 to 80cm in most places. Temperature gradients in the top half of the snowpack were enough to drive faceting, but were less extreem closer to the ground, even though the bottom of the pack is made up of softer facets. No other signs of instability.

All visible snow surfaces were wind affected, either P hard sastrugi, F+ to 1F hard wind deposits or wind skin. Some softer snow down lower on slopes that were sheltered by trees.

After about 1030am winds died down significantly and the sun came out making the afternoon much more pleasant.

Snowpit or crown profile photo or graph: 
Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
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