Variable Snow Conditions on Donner Summit

Location Name: 
Donner Summit
Region: 
Donner Summit Area
Date and time of observation: 
Mon, 01/21/2013 - 12:00
Location Map: 
United States
39° 16' 52.0284" N, 120° 19' 32.9484" W
See map: Google Maps
US


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

Variety of snow surface conditions exist in the Donner Summit area.  Exposed N-E aspects at upper elevations have firm windboard or firmer old snow crusts, lower N-E protected aspects are still holding some soft unconsolidated snow.  South aspects are wind affected in exposed areas and have some soft corn type snow at lower elevations.  Some south aspects were punchy and had a marginal if any freeze from the warm temps at the upper elevations with the inversions over the last week.  The light to moderate East winds were helping to keep most wet snow instabilities on solar aspects to a minimum. 

Photo#1:  10:45am, 7600', South aspect, south side Mt. Lincoln.  3'' of moist snow on top of a ski supportable 1'' melt freeze crust.  Below that was 4'' of colder snow with another stronger 3'' melt freeze crust.

Photo#2:  8200', East aspect, Mt. Judah.  Wind scoured snow surface with firm wind crusts and firmer old snow surfaces.

Photo#3:  South side of Mt. Judah, 7600', 1:45pm.  Small roller ball activity with ski turns on steeper slopes.

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
Clear
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
East
Accumulation rate: 
None
More detailed information about the weather: 

Upper Coldstream Canyon, 12:15pm, 7569', East aspect.

+10c Air Temp, -1.5c snow surface temp, light east winds, Boot Pen 25cm.