Natural Windslab Avalanche & Rapid wind loading McGee Mountain

SNOWPACK OBSERVATION
McGee Mountain NE gully
Submission Info
Forecaster
Wednesday, February 27, 2019 - 3:45pm
Red Flags: 
Recent avalanche activity
37° 35' 0.8088" N, 118° 48' 53.4924" W
Snowpit Observations
More detailed information about the snowpack: 

Toured up McGee Mountain today to see how bad the SW winds could really be and they indeed were hurricane force. Snow surfaces were incredibally eroded with a majority of the dry snow either completely stripped or being actively eroded off the Valentines day rain crust below 10000ft. The starting zone of the prominent NE gullys were loaded with 6-12" of wind deposited snow. A majority of the snow being transported was being harvested from the burst of new snow (2-3")  this morning, but old snow surfaces were obviously being eroded before my eyes and contributing to wind slab development. When I started up the hill around 930am I could see the start zone of the main NE gully and it looked smooth and possible good for skiing... when I got up to the ridge and looked in, it had naturally avalanched during the time I was plowing uphill into a massive headwind. It was a windslab spanning the width of the start zone ~250ft and was 12-16"depth. I categorize it as R4D2N1'vert 500'. The windloaded snow was reactive to ski cuts and slid easily on the old shorn snow surfaces. Winds were not gusting, but were consistently blowing at 70-90mph all day until 200pm when I descended. Standing and hiking the ridge was nearly impossible and visibility off the leeward of the ridge was nill. I was glad to get off the mountain and escape down wind stripped slopes.

 

Snowpack photos: 
Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Gale Force
Air temperature trend: 
Warming
Wind Direction: 
Southwest
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