Donner Summit Observations

Location Name: 
Wildflower Ridge
Region: 
Donner Summit Area
Date and time of observation: 
Fri, 01/14/2011 - 13:30
Location Map: 
United States
39° 18' 27.684" N, 120° 19' 6.708" W
See map: Google Maps
US


Red Flags: 
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Radiational cooling with clear skis overnight allowed the rain crust to freeze in this area.  Ski pen was 0-5cm from 7000-8000' , firm on shaded aspects and softening on solar aspects by early afternoon.  The rain crust was very supportable above 7500', below was a mixture of breakable/supportable crusts that made for some challenging skiing conditions.  The upper snowpack showed weakness just below the rain crust and also 15cm below the surface, both on small weak faceted grains.  Keep in mind that the deepest instability noted was 15cm below the surface and in these areas the surface crust  was strong enough to bridge over the weak layer.  While the ECT was showing propagation was likely on this 15cm buried layer no informal obs showed any problems.

No roller ball activity seen today and no wind transport observed in this area or elevation. 

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

donnersummit2011 01 14 002

Weather Observations
Blowing Snow: 
No
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
East
Accumulation rate: 
More detailed information about the weather: