Frozen rain crusts, and mostly frozen melt-freeze snow in Negro Canyon

Location Name: 
Negro Canyon
Region: 
Donner Summit Area
Date and time of observation: 
Sat, 02/02/2013 - 12:00
Location Map: 
United States
39° 20' 47.3208" N, 120° 18' 19.2852" W
See map: Google Maps
US


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

Overcast skies prevented much softening from occurring in the Negro Canyon area today. A mix of supportable frozen rain crusts and frozen melt-freeze crusts existed on all aspects and up to 7700 ft. and down to the trailhead in this area. Some very limited melting occurred below 6800 ft on a due south facing aspect. Even on this low elevation S aspect only about 1/4 - 1/2 an inch softer snow formed on top of the frozen melt-freeze crust. On the southerly aspects the crusts were several inches thick. On the northerly aspects the rain crusts ranged from 1.5 to 2 inches thick. A dusting of softer snow did exist on top of the rain crust on the sheltered northerly aspects. Below this rain crust colder softer dry snow exists. Ski cuts, hand pits and other observations did not reveal any signs of instability in this area today.

Photo 1: 1/2 of soft melt-freeze snow on top of a frozen melt-freeze crust on a S aspect at 6800 ft.

Photo 2: Frozen crusts on a SE aspect at 7200 ft.

Photo 3: A dusting of soft snow on top of a supportable rain crust on an ENE aspect at 7600 ft. 

Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: