Mammoth Area - Mammoth Crest- Rain Crust & Surface Hoar layers

Mammoth Crest
Submission Info
Sunday, December 15, 2019 - 1:00pm
Mammoth crest 37° 36' 9.8424" N, 119° 2' 13.5996" W
Snowpit Observations
More detailed information about the snowpack: 

It was a splitter blue day in the High Sierra with frosted trees and a return of cold temperatures. It was 16F at 1pm when I dug a snow pit at 9935ft. It was a bit windy up high in the morning, but by mid-afternoon in the Mammoth area it was tranquil and calm. New snow amounts from this weekend’s storm averaged 6”-8” and up to 12” where wind loaded adjacent to cliffs. Southerly and Westerly aspects that were not sheltered were wind shorn with a rain crust on the surface.  Any aspect that was fairly sheltered, even sunny aspects, harbored good skiing conditions if coverage was adequate.  

The warm storm that started out as rain helped lay down a well bonded mat of new snow, although it did establish a crust throughout most of the area. I found the rain layer at 20cm below the surface.  Around 1-2cm in thickness, it was not very robust or composed of solid ice, more like a wafer cookie. Not sure exactly what the rain/snow elevation turned out to be during this event, but the rain crust should become harder to find as you go higher. It will be good to investigate this further.

In addition I found a layer of surface hoar 50cm below the surface. How widespread the surface hoar layer is throughout the area will need to be tracked as we were not finding it in other areas this week such as the Sherwins, Lee Vining and Virginia Lks area. During stability tests, I got hard failures on both the rain crust and surface hoar layer, but it was worth noting that they were both quite planar in nature and well defined and apparent in the stratigraphy of the snow profile.

HS: 145cm

CT23Q2 @125cm

CT24Q2 @95cm

ECTN26 @95cm

Surface conditions and cold temperatures made for fantastic skiing and I did not observe any instability on kick turn tests, or ski cutting deeper loaded pockets. Will be advantageous to track the two layers of concern (rain crust, surface hoar) and go from there.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Snowpit videos (tests, etc): 
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