Widespread Avalanche Acvtivity

Location Name: 
Widespread Avalanche Acvtivity
Region: 
BWRA
Date and time of avalanche (best estimate if unknown): 
Wed, 04/19/2017 - 10:10
Location Map: 


Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Rapid warming
Obvious avalanche path
Terrain Trap

Observation made by: Avalanche Specialist
Avalanche Observations
Avalanche Type: 
Wet
Dry
Slab
Loose/Point-Release
Slope: 
44degrees
Trigger type: 
Snowboarder
Crown Height: 
1 ft
Aspect: 
North
Weak Layer: 
Storm Snow
Avalanche Width: 
400ft.
Terrain: 
Above Treeline
Elevation: 
10 535ft.
Bed Surface: 
Old Snow
Avalanche Length: 
750ft.
Number of similar avalanches: 
More than 10
Number of people caught: 
1
Did the avalanche hit a building, vehicle, or structure?: 
No
More detailed information about the avalanche: 

Details are limited for this Snowboarder triggered Wind-slab avalanche that happened sometime Wednesday morning in the Leavitt Cirque. I hope the panoramic & the next two photos show how serious this situation could have been. Based on known conditions & visual assumptions, it looks like for this snowboarder turn three compromised the 1-2' wind-slab & propigated a fracture across the slope +400'. The fracture stepped-down into an older wind-slab pulling out another pocket nearly a foot deep. The size & mass of the slide could bury a car & destroy a wood home, in the snowscience realm we would give this a destructive rating of D3(out of 5). Just focusing on the snowboarder (ARu) the avalanches size relative to potential slide path is medium with a rating of R3(out of 5). To code this avalanche HS-ARu-R3-D3-O = Hard-Slab; Unintentinally Snowboarder Triggered, Relative Size 3; Destructive Force 3; Broke Into Old Layers.

Across the BWRA Wet-Loose, Dry-Loose, Cornice Fall, & Wind-Slab Avalanches have been seen above & below treeline on all aspects. A report of a snowmobile triggered Wind-Slab avalanche in the trees pushed a rider & machine into a tree-well. Avalanches are still happening out there & in large size & widespread quantity effecting skiers & snowmachiners alike.

Don' take your Safety lightly, Being Lucky Isn't A Backcountry Strategy!

Avalanche Photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
West
Accumulation rate: 
None
More detailed information about the weather: 

Rapid warming & direct sunlight on snow surface is allowing loose-wet avalanches to occur.