Snow Pit from Castle Pass area

Location Name: 
North aspect slope below Thumb Rock, .5 miles NE of Castle Pass
Region: 
Donner Summit Area
Date and time of observation: 
Sun, 03/28/2010 - 14:15
Location Map: 
United States
39° 21' 53.1" N, 120° 21' 40.644" W
See map: Google Maps
US


Red Flags: 
Obvious avalanche path
Observation made by: Public
Snowpit Observations
More detailed information about the snowpack: 

 We dug this pit below a cornice on a north facing slope below the Thumb Rock area - apprx. 1/2 mile NE of Castle Pass.

 

Compression Test #1: On CT 10 a crack appeared at 253 cm and the slab above slipped downhill a few cm.  As I pressed gently to remove the slab above 253 cm so I could examine the bed surface, the column sheared cleanly at 247 cm.  There was an obvious graupel layer on both the 247 cm and the 253 cm bed surfaces.

Compression Test #2: The layer above 253 cm suddenly slipped forward about half way off the column while I was cutting the back of the column.  Again I found graupel on the bed surface.

HS: 277 cm.

Boot Penetration: 10 cm.

Observed no signs of recent avalanche activity on similar (N aspect) slopes.  Roller balls observed on SE and S aspect slopes.

 

 

 

Snowpit or crown profile photo or graph: 
Weather Observations
Blowing Snow: 
No
Air temperature: 
Above Freezing
Wind Speed: 
Moderate
Precipitation: 
Air temperature trend: 
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: