Snowpit on Castle Peak

Location Name: 
Castle Peak-above Thumb Rock
Region: 
Donner Summit Area
Date and time of observation: 
Sun, 01/30/2011 - 12:30
Location Map: 
United States
39° 21' 54.2196" N, 120° 21' 27.6156" W
See map: Google Maps
US


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

Dug pit at Location

Elevation 8300ft

Air temp 35F

Wind: light (3-5), variable
Conditions: 80% cloud coverage, no precip.
Test on windward side of ridgetop, SW-facing, 10-15% slope

10" top layer of new snow over hardpack layer. No shear failure after 5 full-arm shovel compressions.
There was a solid ice layer at 15-16"
Boundary surface between new snow and base layer was uneven.
Fair to good adhesion between new snow and base layer.
With effort, able to provoke a clean fracture at base of the column at 31" 

A separate shovel compression test performed on the opposite (N) side of the site above produced similar results.

Attempts to trigger sloughs by ski-cutting 30º - 35º pillows on the windward (W) side of ridge at the same location were unsuccessful.  

No sloughing or slabs observed when descending 28-30º NW-aspect off CP. Tried to trigger failure on a ± 35-38º rollover at the base of the aspect without success.

 

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
West
Accumulation rate: 
None
More detailed information about the weather: