Slab failures on Hidden Peak

Location Name: 
Hidden/Jakes
Region: 
West Shore Area
Date and time of avalanche (best estimate if unknown): 
Mon, 02/20/2017 - 15:06
Location Map: 
United States
38° 58' 42.4344" N, 120° 7' 19.128" W
US


Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain

Observation made by: Public
Avalanche Observations
Avalanche Type: 
Slab
Slope: 
15degrees
Trigger type: 
Skier
Crown Height: 
1 ft
Aspect: 
Southeast
Avalanche Width: 
40ft.
Terrain: 
Below Treeline
Elevation: 
8 500ft.
Avalanche Length: 
100ft.
Number of similar avalanches: 
5-10
More detailed information about the avalanche: 

I toured around from the Jake's parking lot over to Hidden Peak and back yesterday afternoon, and found tons of naturally releasing slab activity in the upper third of the mountain, especially on slopes with south to southeastern aspects.  Cracks, crowns (up to maybe 15"), and debris were observed on a wide variety of slope angles and even in surprisingly wooded pockets.  The attached image is of a 10-12" crown that I stumbled into, which wrapped around to an open south-facing slope.  I didn't bother getting a closer look to see the full extent of it.  While on a 15 degree slope, I accidentally kicked off a 14-15" slab at the lip of a SE-facing gully that quickly dropped off.  That crown was maybe 40' across.  Some of it got hung up on trees towards the top, but most of it ran down and released the entire gully into a terrain trap below.  I have video of this, but apparently the file is too large to load.  The snow was considerably heavier (moisture content) lower down by the road, and I was able to kick off some 6-8" slabs on the steepest pitches, but only if I made a bit of an effort to do so.

Avalanche Photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Calm
Precipitation: 
Snow
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

Some swirly breeze at the very top, but mostly pretty calm.