Variable Conditions on Castle Peak

Location Name: 
Castle Peak
Donner Summit Area
Date and time of observation: 
Tue, 01/02/2018 - 12:00
Location Map: 
United States
39° 22' 3.5364" N, 120° 21' 12.3984" W

Red Flags: 
Whumphing noises, shooting cracks, or collapsing

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

Highly variable conditions existed on Castle Peak today. Sun-exposed slopes on S-SE aspects had soft wet corn snow above a firm supportable layer of frozen snow. Northerly aspects held a mix of frozen scoured surfaces, wet sticky snow, breakable crusts, firm elevated previous tracks, and some areas of lingering soft unconsolidated snow in below treeline untracked open areas.

Below the surface, on northerly aspects, loose weak snow remains widespread, but signs of instability were isolated because there were only a few small areas where a slab layer existed above this weaker snow. In those isolated areas some signs of instability existed including unstable snowpit test results on NW aspect at 8300 ft. (see snowpit) and a small whumpf on an upper elevation NW aspect at 8800 ft. where a hard old wind slab existed above the persistent weak layer (at the coordinates attached to this ob). This collapse only involved a small 8 ft. by 8 ft. area on the slope. 

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Air temperature trend: