Snow Conditionsin the Sherwins

Mammoth Rock
Submission Info
Friday, December 6, 2019 - 2:45pm
Red Flags: 
Recent loading by new snow, wind, or rain
37° 36' 41.1624" N, 118° 59' 42.3168" W
Snowpit Observations
More detailed information about the snowpack: 

I went for a tour today in the Mammoth rock area to get a look around before this weekend's storm rolls in. When i left the car at approximately 11 this morning, the temperature was below freezing, and a light to moderate SW wind made things feel quite brisk. Low elevation cloud cover was pretty thick leaving the car, and I observed fairly widespread surface hoar up to about 9000’ where the clouds gave way to blue skies.   It will be interesting to see if this sticks around as this weekend's storm comes in. I toured up to Sherwin ridge and topped out at around 10,000’ at the top of the Hose.  The wind was Moderate from the SW along the ridge, and the temperature was about 28°F. The windward side of the ridge was pretty well stripped of snow, but I did observe some active loading along the Mammoth crest.

Wind affected snow was evident throughout much of my tour today, and significant signs of wind loading were evident along the ridge. Numerous hand sheers along my ascent identified 1Finger/Fist hard windboard ~15-20 cm thick.  I found this to be reactive to moderate prying force.  I dug a more thorough snow profile on a NE aspect at 9800’ and found this layer to be unreactive to compression tests. However, I did identify a density change about 30 cm from the surface that was reactive to my tests (ECTP13). I Suspect this deeper layer is from a loading event that occurred during the most recent storm.  See attached Profile for more details.


I dug a second pit in some well-protected trees at about 9200’ and found the snowpack to be right-side-up, about 80 cm deep, and I did not observe anything too concerning.


Overall the coverage feels pretty good for this early in the season, and surface conditions were quite pleasant.  Hopefully, the heavy precipitation predicted this weekend will help to bury the remaining preseason obstacles. 


Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
Air temperature: 
Below Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 
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