Chicken Wing

SNOWPACK OBSERVATION
Submission Info
Forecaster
Monday, February 27, 2017 - 11:00am
Red Flags: 
Recent loading by new snow, wind, or rain
37° 45' 27.144" N, 119° 2' 10.932" W
Snowpit Observations
More detailed information about the snowpack: 

Route: Up N and NW aspects of Chicken Wing on one of the standard skin tracks from the parking at 395. Up to summit, down NNE aspects back to car.

1000- Sky: Few clouds; Wind: Calm; snow surface warming in sunny areas at and below 8500', a few roller balls from below cliffs; Tair already: 2deg C; Tsurf: -3deg C. Clouds and wind increased throughout midday to scattered and light from the WSW respectively, preventing much more warming today.

1100- Test profile on a NNE aspect, 28 deg, leeward slope at 9360', about 300 vertical feet below the summit in a large opening in the trees. (See attached profile.)

1200- Kick tests and stomping on almost every cornice and convexity along the summit ridge: 10cm thick wind slabs where touchy but not propagating (see photo). All cracking was localized. Cornice drops didn't trigger wind slabs down slope (see video). Wind affects in the White Wing area were widespread and obvious (see photo). Winds at the summit were consistently light with moderate gusts both from the SW. Very occasional light snow showers.

Impressions: There is a shallow wind slab on the surface (about 10cm thick) on specific leeward features on open ridge tops. These shallow slabs are touchy but may need steeper and open slopes to propagate. There is also a deeper (down to about 65cm, depending) wind slab from the strong winds over the past few days that is still sitting in the snowpack down lower on leeward slopes and may be more widespread. This slab can still propagate in large column tests but seems more stubborn and perhaps less likely for a human to trigger. Of course, if it were triggered from the right weak point the consequences would most likely be higher than those of the thinner slab on the surface.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Touchy but shallow and localized cracking.
Wind affects in the White Wing area.
Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: 

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