Poor snow pack structure, Propagating test results in the Lakes Basin

Lake Mary trees
Submission Info
Friday, March 20, 2020 - 4:45pm
Red Flags: 
37° 35' 48.3468" N, 119° 0' 6.9948" W
Snowpit Observations
More detailed information about the snowpack: 

I went for a quick tour into the Lakes basin this afternoon to poke my head into the snow and get a look at how the lower snowpack is accepting the new load.  The afternoon was chilly and overcast and winds were light out of the SW.  the new snow from last week’s storm seems to be consolidating nicely and Ski pen has reduced to 30 cm from the knee to waist deep slogging I experienced in this area last weekend.

We dug in at 9000’ on a due North aspect and found the structure to be quite poor. The total height of snow was 132cm, with about 40 cm of new snow on top of a very weak base comprised of large-grained facets and a variety of MF crusts.  Stability tests highlighted our layer of concern 53 cm from the surface. This layer of large-grained facets was sandwiched between two distinct MF crusts. This weak layer showed sudden planer fracture character in our compression tests and showed propagation propensity on both our long column tests. (ECTP25@79cm, PST30/100END@79cm) 

No cracking or collapsing was observed during our tour today although there have been several reports of large collapses in the area over the last couple days. 

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Snowpit videos (tests, etc): 
Weather Observations
Blowing Snow: 
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

Mostly cloudy skies, light winds and cold temperatures made for a brisk afternoon in the Lakes Basin. 

-- placeholder --

ESAC receives significant financial support from ...