Loose Wet Point Releases on Donner Peak

Location Name: 
Donner Peak
Region: 
Donner Summit Area
Date and time of avalanche (best estimate if unknown): 
Wed, 03/30/2016 - 12:00
Location Map: 
United States
39° 18' 41.7708" N, 120° 18' 50.4936" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Rapid warming
Obvious avalanche path
Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
Wet
Loose/Point-Release
Slope: 
39degrees
Trigger type: 
Natural
Crown Height: 
Less than 1 ft
Aspect: 
East
Weak Layer: 
Other
Avalanche Width: 
40ft.
Terrain: 
Above Treeline
Elevation: 
7 600ft.
Bed Surface: 
Other - explain below
Avalanche Length: 
200ft.
Number of similar avalanches: 
5
More detailed information about the avalanche: 

Several natural loose wet point releases occurred near rock bands on the E face of Donner Peak. Most of these were relatively small and but some did entrain enough snow to interfere with backcountry travel. Some of these slides looked like they occurred on 3/29 and some occurred today on 3/30. Elsewhere on Donner Peak wet sticky snow existed on all aspects up to about 7800 ft. Ski cuts on steep ENE-E-SE facing slopes produced additional small loose wet point releases, roller balls, pinwheels up to .6 m in diameter, and ski width wide loose wet sluffs. Ski cuts on wind loaded N-NE aspects above 7600 ft. and did not produce any cracking or signs of instabilities. Little evidence of wind scouring by NE winds existed in this area. 

Photo 1: Loose wet point releases on the east face of Donner Peak.

Photo 2: Skier triggered loose wet sluffs, roller balls, and pinwheels on an E facing test slope at 7400 ft. 

Photo 3: Skier triggered pinwheels on an ENE aspect at 7600 ft. 

Avalanche Photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
Snow
Air temperature trend: 
Static
Wind Direction: 
Northeast
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Periods of warm sun mixed with snow flurries that did not produce any accumulation in this area today.