Snow conditions in the Sherwins

Mammoth Rock
Submission Info
Friday, February 15, 2019 - 11:45am
Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Snowpit Observations
More detailed information about the snowpack: 

I toured up above Mammoth Rock today with the goal of finding the upper reaches of our recent rain event.  I was not successful in my goal.  My high point was at about 9600,’ and the rain crust was still relatively thick at this elevation.  There was notably less new snow than I had expected to see and surface snow was very low density.  Things became much more slab-like as the day progressed and shooting cracks became more widespread within the new snow above the rain crust.  Most cracks were 3-4 ft in length and localized to my ski tips.  However, I initiated one shooting crack about ~25~ ft long while ski cutting a steep convex feature. No wumphing or recent avalanches were noted on my tour today, though stability seemed to be decreasing and things started to feel more “touchy” as the snow totals added up throughout the day. 


I dug in on an NE aspect around 9000’.  HS ~370~ cm, HNS 55cm.  

The rain crust at this location was about 5 cm thick and pretty stout ice.  Stability tests highlighted numerous density changes within the new snow but most concerning was an ECTP 24 below the crust layer. This ice layer is sitting on top of 4f storm snow from last weekend. Overall the new snow is right side up and I suspect as things settle out the crust layer will become less reactive.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Snowpit videos (tests, etc): 
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 snow was a constant today and winds were strong.  In general, winds seemed to be blowing from the southwest; however, localized winds were all over the board with strong gusts blowing upslope at times. Temperatures were cold and continued to drop through the day.

-- placeholder --

ESAC receives significant financial support from ...