Rain on Snow in the Sherwin

Mammoth Rock
Submission Info
Wednesday, February 13, 2019 - 12:30pm
Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
37° 36' 53.9532" N, 118° 59' 29.8752" W
Snowpit Observations
More detailed information about the snowpack: 

Went for a quick tour up above Mammoth rock this morning to get a look at how surface conditions are responding to the recent change in the weather.   Leaving my car at the end of old mammoth rd around 10 am it was still snowing, but by 1230 the rain/ snow line had risen to around 9000’.  Even still, precipitation seemed to be changing from grauple to rain and back again.

Hand sheers highlighted numerous surface instabilities reactive to easy force. Extreme winds yesterday led to pretty stout wind board in exposed areas, and at lower elevations, the rain has saturated the surface snow creating an upside down situation. Digging a quick pit on a sheltered NE aspect area around 9000’ I found the top 2” had saturated.  This upper storm layer failed easily during my compression test (CTE2) though I did not see propagation on my extended column test. I did not note any recent avalanche activity this morning, but I suspect as the rain continues this afternoon and evening that stability will rapidly decrease and loose wet avalanches, as well as wet, heavy storm slabs, will become much more likely. 

Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 
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