Skier triggered wet snow sluffs on Jake's Peak

Location Name: 
Jake's Peak
Region: 
West Shore Area
Date and time of avalanche (best estimate if unknown): 
Tue, 04/19/2011 - 12:15
Location Map: 
United States
38° 58' 2.4636" N, 120° 6' 43.7472" W
See map: Google Maps
US


Red Flags: 
Recent loading by new snow, wind, or rain
Rapid warming
Obvious avalanche path
Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
wet,loose,
Trigger type: 
Skier
Aspect: 
East
Avalanche Width: 
10ft.
Terrain: 
Below Treeline
Avalanche Length: 
150ft.
Number of similar avalanches: 
More than 10
More detailed information about the avalanche: 

Rain on snow event yesterday (April 18) created wet snow in the top 30 to 60cm at all elevations traveled on Jake's Peak (6,800' to 9,150'. By noon the weak melt freeze surface crust that formed Monday night was either fully melted or nearly fully melted to less than 1cm of crust remaining at the base of around 10cm of wet snow with more wet snow below. N-NE aspects above 9,000' were the exception with the melt freeze surface crust remaining supportable at noon. A trace of new snow on top of crust areas existed above 8,500'. Isolated pockets of supportable crust remained in shadows below treeline down to 7,200' on E aspects.

Videos: Skier triggered sluffs were very easily skier triggered on E aspects slopes steeper than 35 degrees (noted lat/long). The instability was limited to the top 4 inches of wet snow but would entrain more snow with downhill progress.

Avalanche observation video: 

201100419 Jake's Pk wet sluff 1.MOV

201100419 Jake's Pk wet sluff 2.MOV

Weather Observations
Blowing Snow: 
No
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
West
Accumulation rate: 
More detailed information about the weather: