Donner Summit Observations

Location Name: 
Donner Summit
Region: 
Donner Summit Area
Date and time of observation: 
Sat, 12/11/2010 - 14:30
Location Map: 
United States
39° 18' 45.1872" N, 120° 19' 12.0288" W
See map: Google Maps
US


Red Flags: 
Recent loading by new snow, wind, or rain
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Snow surface consists of 25-30cm of wet damp snow grains.  Total snow depth at 7500' in the 170cm range.  The mid snowpack is mostly moist rounded grains, overall good stability throughout.  CT's showed mostly no results with only a couple of moderate shears between the wet surface snow and the rounded layer below.  Below 7500' you could easily push your ski pole through the wet snow all the way to the ground, it was very unsupportable around rocks and bushes.  Lots of roller ball activity but limited point releases seen today.  Surface temp -1c, air temp +3c.  Could easily see and hear water flowing throughout the tour. 

 

Pic 1&2: Sagging cornices and cornice failure at 7500' N/E aspects.

Pic 3: Rain runnels and significant snow melt over the last week below 8000' from the warm temps and rain.

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Air temperature: 
Above Freezing
Wind Speed: 
Calm
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: