North Bowl Avalanche

Location Name: 
Lakeside/ Couloir
Region: 
Selkirk Mountains
Date and time of avalanche (best estimate if unknown): 
Fri, 12/14/2018 - 13:30


Red Flags: 
Recent loading by new snow, wind, or rain
Observation made by: Public
Avalanche Observations
Avalanche Type: 
Slab
Slope: 
38degrees
Trigger type: 
Skier
Crown Height: 
2 ft
Aspect: 
Northeast
Weak Layer: 
Storm Snow
Avalanche Width: 
100ft.
Terrain: 
Below Treeline
Elevation: 
5 800ft.
Bed Surface: 
Old Snow
Avalanche Length: 
250ft.
Number of people caught: 
1
Number of partial burials: 
1
More detailed information about the avalanche: 

SS- ASu-R1-D1.5 occured while ski cutting a small terrain feature. Wind loading created a 12-18" wind slab, presumed to be overlying the 11/27 rain crust and associated facets. Explosives work yesterday resulted in R2-D2.5 higher up in bowl, releasing new and wind deposited snow in typical start zones. Ski cutting had produced no obvious signs of instability in similar terrain. I entered the slope and it fractured approximately 30' above me. I tried to ski out but was unable to. Both skis were removed by the slide and I stopped approximately 30' above the toe, buried to the waist. Wind slab broke up into softer slab, allowing me to remain on top. Current hazard rated Moderate at all elevations. Mitigation efforts in previous 48 produced widespread settlement but other than ridge top start zones, no slides (ski cutting other terrain on 12/12 resulted in multiple R1D1 skier and remote slides). Ski cutting had produced no slides in previous 48 hours. 20" of new snow in previous three days with moderate to high SW winds. Terrain feature and location created isolated cross loaded wind slab. First trip into the terrain of the season.

Avalanche Photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: 

See above.