Recent avalanche activity, heavy snow, strong winds in the Sherwins

Mammoth Rock
Submission Info
Wednesday, March 25, 2020 - 2:45pm
Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
37° 36' 42.5628" N, 118° 59' 40.1532" W
Snowpit Observations
More detailed information about the snowpack: 

I went for an afternoon tour to Sherwin ridge above mammoth rock today. Heavy snow and strong winds were actively blowing snow at all elevations creating large drifts below treeline and filling in the recent skin track. In non-wind affected areas I measured about 8” of fist hard snow from today's storm. In protected areas, this new snow was resting on 4f settled snow from last weekend and in more open areas the underlying snow had a distinct temperature crust (1F-P).  Upon reaching it became immediately apparent that heavy transport was occurring. Visibility was limited and the stream of snow pouring over the freshly formed cornices made it difficult to see the slope below. However, walking the ridge towards the top of the hose I was able to asses that virtually the whole ridge had run naturally.  I found a low angle entrance and made my way out of the wind to get a better look at the fractures and resulting debris. Admittedly crowns were difficult to tell from the cornice that remained, and the paths were actively reloading. I would estimate slab depth to be between 8-20” with debris running about 100-150’. Debris piles ~4’ deep.   In addition to the natural activity, I observed shooting cracks on less steep but equally loaded slopes up to 20’ long. The slab in this location was 4F/F and about 10” deep. 

No other signs of instability were noted today but I suspect Loose-dry sloughs could have been sizable in steep sheltered terrain.

Weather Observations
Blowing Snow: 
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
Greater than 1 in. per hour
More detailed information about the weather: 

Heavy snowfall and strong winds were the driving force of change today. Temperatures remained below 20°F and the wind chill had me bundled up pretty good.  


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