Wet Slides on Janine's

Location Name: 
Janine's
Region: 
Desolation Wilderness Area (including Emerald Bay)
Date and time of avalanche (best estimate if unknown): 
Tue, 04/13/2010 - 11:00
Location Map: 
United States
38° 54' 56.808" N, 120° 7' 33.186" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Rapid warming
Obvious avalanche path
Terrain Trap
Observation made by: Professional Observer
Avalanche Observations
Avalanche Type: 
wet,
Slope: 
40degrees
Trigger type: 
Snowboarder
Crown Height: 
1 ft
Aspect: 
Northeast
Weak Layer: 
Storm Snow
Avalanche Width: 
80ft.
Terrain: 
Near Treeline
Elevation: 
8 200ft.
Bed Surface: 
Old Snow
Avalanche Length: 
300ft.
Number of similar avalanches: 
5-10
More detailed information about the avalanche: 

Very warm temps today - made it easy to trigger wet loose avalanches. All of the slides observed were R1 D1.

Photos 1 and 2: Human triggered at 8200ft 40 degree NE slope. Weak layer was storm snow, bed surface was old snow. Images make this look more consequential than it was - still only a D1.

Photo 3: Cornice drop triggered at 9200ft 40 degree N/NE slope. Weak layer was within storm snow, bed surface storm snow, failed to step-down to old snow. Cornice drop just next to this, on a due N aspect, failed to initiate anything.

Photo 4: Several more human triggered on Janine's, 9500ft N/NE

Avalanche Photos: 
Weather Observations
Blowing Snow: 
No
Air temperature: 
Above Freezing
Wind Speed: 
Calm
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Accumulation rate: 
None
More detailed information about the weather: 

Significant thunderhead build-up by late morning appeared to contribute to rapid warming