Negro Canyon Obs.

Location Name: 
Negro Canyon
Region: 
Donner Summit Area
Date and time of observation: 
Sun, 12/13/2009 - 14:00
Location Map: 
United States
39° 20' 36.9276" N, 120° 18' 22.9932" 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: 

We moved through some similar terrain as yesterday, N-E aspects, but were able to get up to some higher elevations.  Above 7000' HS was around 155cm.  We had no whumping/ collapsing or shooting cracks, all of which were present yesterday.  In a couple different pit locations we had consistent CT-2 Q2 results down 15-20cm from the surface, this was a heavier, 4f hardness, wind loaded layer.  Below that layer the snowpack had a uniform right side up presence going from fist hardness to 4F, to 1F to the 11/22 rain crust.  The 11/22 RC with facets on top was present everywhere we looked but was not reactive.  Up higher on an exposed ridge we were able to get several cornices to break off easily, no slab fracture propagation happened on the slopes below, the cornice blocks just rolled down slope without entraining much snow.  Visibility was variable but no natural or human triggered avalanches were observed today.            

 

 

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
Snow
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: