Donner Summit Observations

Location Name: 
Donner Summit
Region: 
Donner Summit Area
Date and time of observation: 
Tue, 03/15/2011 - 11:00
Location Map: 
United States
39° 18' 42.1416" N, 120° 19' 18.5664" W
See map: Google Maps
US


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

Observations from above Old 40 and Sugar Bowl Academy up to 7400-7500'.  Wind exposed areas scoured down to old rain crust.  Snowing 1+''  per hour by midday with steady strong SW winds.  Cracking and shooting cracks were common in wind loaded terrain with skipen from 0-4''.  Cornices were very sensitive and easily failed with a ski kick but propagation was limited on test slopes with cornice drops or ski cuts.  The upper snowpack showing several different layers from the start of this storm cycle on Sunday with some density changes and rain effects.

Photo:  Shooting cracks in wind loaded terrain at 7400', north aspect.

Snowpack photos: 
Snowpit videos (tests, etc): 

donnersummit2011 3 15 011

donnersummit2011 3 15 012

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Strong
Precipitation: 
Snow
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
Greater than 1 in. per hour
More detailed information about the weather: 

Heavy rain in town at mid morning.  Snow level on Old 40 @ 6400' slightly warming by midday.