Small avalanche on E Judah

Location Name: 
East Face of Mt. Judah
Region: 
Donner Summit Area
Date and time of avalanche (best estimate if unknown): 
Sat, 02/28/2015 - 12:30
Location Map: 
United States
39° 17' 55.0824" N, 120° 18' 48.672" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Obvious avalanche path
Observation made by: Public
Avalanche Observations
Avalanche Type: 
Dry
Slab
Slope: 
40degrees
Trigger type: 
Skier
Crown Height: 
Less than 1 ft
Aspect: 
Northeast
Weak Layer: 
Storm Snow
Avalanche Width: 
30ft.
Terrain: 
Near Treeline
Elevation: 
7 850ft.
Bed Surface: 
Storm Snow
Avalanche Length: 
300ft.
Number of similar avalanches: 
1
More detailed information about the avalanche: 

Small slab avalanche (SS-ASc-R1D1), intentionally triggered on a convex roll. Avalanche ran full track into the trees at the base of the path. Weak layer was a lower density layer within the storm snow, approx 30cm down. One other similar avalanche was also triggered, which ran full track as well. Both events were not quite big enough to bury a skier, but burial would be possible with a big enough terrain trap (like a gully feature). Numerous skier triggered loose dry avalanches were also observed, which ran for quite a distance as well.  

Extra note: West facing slopes below 7800' had formed a very distinct higher density layer (3cm) on the surface by 14:00, due to rising temps. E &N slopes were much less affected. 

Avalanche Photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Wind Speed: 
Light
Precipitation: 
Snow
Air temperature trend: 
Warming
Wind Direction: 
West
Accumulation rate: 
Less than 1 in. per hour