Mammoth Rock, Sherwins

Mammoth Rock, Sherwins
Submission Info
Thursday, April 13, 2017 - 2:45pm
Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Mammoth Rock, Sherwins 37° 36' 51.93" N, 118° 59' 29.4108" W
Snowpit Observations
More detailed information about the snowpack: 

Toured up in to the Sherwins via the standard route adjacent to Mammoth Rock up to the base of Mammoth Rock Bowl then over toward The Hose. Limited visibility prevented good visual feedback throughout the tour. Frontal passage appears to have occurred around 400 PM with periods of moderate to strong winds, snowfall rates of 2 cm (~1") per hour or greater. Consistent 10 to 20 cm new snow over a melt/freeze crust observed throughout but variable coverage due to winds. Minor cracking around tree-wells(length of ski) with drifting of 30 cm  or better along the ridge directly above Mammoth Rock. 1 small natural Wind Slab failure (D1/R1-), Poop Chute. Wind Slabs forming above ~8000' where sufficient new snow exists for transport, potential increases with elevation. Hand shears easy to failure on isolation, ~10cm thick (~4"). Test slopes yielded only surface sluffs. Scattered old now frozen rollerballs below ~9500', which were a ski hazard. Two rather large debris fields observed from the last avalanche cycle (4/6-4/8). Lower Hose ~ 9200' failed with debris pilling up in the trees (~8300') with several 20 cm  plus (~10") trees embedded in the debris. Debris looked very wet in nature due, large chucks and a very narrow and tall debris field. Second debris field was under Mammoth Rock, start elevation ~8700', again large chunks. Both ENE aspects. 

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: 
Less than 1 in. per hour
More detailed information about the weather: 

Moderate to strong SW to W winds depending on channeling. 10 to 20 cm new snow. Variable depth due to winds. Frontal passage ~400 pm with strong gusty winds and an intense burst of snowfall for about an hour. Snowfall intensity decreased after ~500, light snow showers and occasional cloud breaks. Continued moderate to strong winds, very gusty. Only got blown over once. 

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