Wind slabs and blowing snow on Donner pass

Location Name: 
Wild flower Ridge
Region: 
Donner Summit Area
Observation Date & Time: 
Friday, December 20, 2019 - 03:15
Location: 
39.312533, -120.322386
See map: CalTopo
Is this an Avalanche Observation?: 
No


Conditions Alerts:

  • Recent Loading
  • Recent Loading›Blowing Snow
Observation made by: Educator at Alpine Skills International (ASI)

Tabs

Observation
Description of Snow, Weather, and Avalanche Conditions: 

Our party targeted a northern low angle slope on the leeward side of a ridge, easy to see it was a wind affected area.  We observed blowing snow on ridge lines and active wind loading on leeward areas. CT showed a variety of sudden/ resistent planar breaks through a series of wind slabs. No propagation was observed with larger column tests. Resistance tests showed a "right side up" snow pack gradually becoming more firm, from fist at the surface to pencil above crust. 81cm down from the surface was the 12/13 rain crust. 

Hide Snowpack Details
Total Snow Depth: 
210cm
Persistent Weak Layers: 
Not observed
Hide Terrain Details
Terrain: elevations: 
Near Treeline
Terrain: aspects: 
N
Hide Weather Details
Elevation of Observation: 
7000 - 8000 ft.
Blowing Snow: 
Moderate
Wind Direction: 
West
Wind Speed: 
Moderate
Sky Cover: 
Increasing clouds
Precipitation: 
None
Air temperature: 
Below Freezing
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