New Snow on Castle Peak and Andesite Ridge

Location Name: 
Castle Peak | Andesite Ridge
Donner Summit Area
Date and time of observation: 
Fri, 01/19/2018 - 12:45
Location Map: 
United States
39° 21' 3.69" N, 120° 22' 0.2136" W

Red Flags: 
Recent loading by new snow, wind, or rain
Obvious avalanche path

Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

20 to 25 cm (8 to 10 inches) of new snow existed in the Castle Peak - Andesite Ridge area today. This snow rested on top of thick, strong supportable rain crust. Observations and tests showed the new snow to be right side up (it got less dense near the surface and denser near the bottom) and indicated that it has bonded well to the old snow surface and to itself. In areas where wind loading traditionally occurs some small and fragile cornices had formed above the leeward slopes. Ski kicks on cornices above wind-loaded test slopes caused these cornices to fail well away from their edges but the cornices pieces dropping onto the slopes below did not trigger any signs of wind slab instabilities. Some very small minor cracking that only traveled about 15 to 45 cm (6 to 18 inches) from my ski did occur on a few wind-loaded test slopes. 

Snowpit tests on a sheltered NW aspect targeting the old persistent weak layer did not show any signs of lingering instability. See attached snowpit from the shoulder of Castle Peak. 

Photo: Minor cracks that barely extend away from my skis on a traditionally wind-loaded test slope on Andesite Peak.  

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
Air temperature: 
Below Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: