South Lake - Mt Thompson

N. Couloir on Mt Thompson
Submission Info
Monday, December 19, 2016 - 12:00pm
37° 8' 23.0712" N, 118° 36' 20.0376" W
Snowpit Observations
More detailed information about the snowpack: 

-Toured from Parchers Resort (driveable with 4x4 thru snow to ~1/2mi beyond parchers), to end of Rd at South Lake, to Mt Thompson and back.

-about 6-18" of snow at southlake level, increasing to ~18-24" at 11,500', to 8ft in places above 12,000'.

-Lots of evidence of wind in upper elevations (above 11,000') during and right after storm, but no new wind effects for the past few days.  No sensitive windslabs found.  Some handpits/hand shears in areas of wind deposit failed 3-5" down, but all with moderate to hard force.  ECT tests did not propogate.  Test pit dug at 12,600', N facing slope, 265cm of total snow, see attached.  Stability tests showed inconsistent failures, with moderate to hard force.  

-Lots of faceted snow was found in shallow areas around rocks, but the talus nature of the area made these facet pockets very patchy and inconsistent across even short distances of a slope.

-No signs of instability were noted today.  All the possible windslabs have had a few days to stabilize, and seem to be of limited concern now.  

-High temperature gradient in upper snowpack.  The clear cold nights have led to a good bit of faceting of the upper snowpack.  This isn't a stability concern now, but these facets could be a weak layer for new snow to fail on in the future. 

-Also of note, lots of old 1.5-2.5' crowns were visible all around upper elevations on NE-N-NW facing slopes around the 12,000' level, mostly below rock bands. These looked like they occured near the end of last week's storm.   

-Thanks to Zak Mills and Jason Templeton for breaking the trail most of the way the day before!

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Air temperature: 
Below Freezing
Wind Speed: 
More detailed information about the weather: 

Clear calm beautiful day!  A bit cold (-2.5deg C at 12,600' at noon). Some high clouds.

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