Lakeside

Location Name: 
Lakeside
Region: 
Selkirk Mountains
Date and time of avalanche (best estimate if unknown): 
Thu, 01/25/2018 - 07:50


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

Observation made by: Public
Avalanche Observations
Avalanche Type: 
Slab
Slope: 
38degrees
Trigger type: 
Other - explain below
Crown Height: 
10 ft
Aspect: 
Northeast
Weak Layer: 
Other - explain below
Avalanche Width: 
750ft.
Terrain: 
Near Treeline
Elevation: 
6 354ft.
Bed Surface: 
Other - explain below
Avalanche Length: 
2 400ft.
More detailed information about the avalanche: 

Lakeside pulled with a double (2Kg) explosive placed by Ski Patrol. AE-HS-R3-D4 on combination of facets, rounding surface hoar, and poly crystals size 2.0mm on 11/29 rain layer. Deep hard slab cleared trees, displaced ice from Colburn Lake, and the toe of the debris ran approximately 100' into the tress below the lake. Approximately 50% of historical avalanche path affected in width and 85% of length. Prior to lift access and regular ski compaction/explosives control, this path ran on the sixth explosive placement on the mitigation route and toe of debris was on Vagabond.
Approximately 750' wide, 2400' ground length, 75,000 square meters, and alpha angle of 22 degrees.
Crown and slide investigated by members of IPAC and Ski Patrol.

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Strong
Precipitation: 
Snow
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

Strong overnight winds combined with 28" of storm snow over previous 3 days and cooling temps overnight contributed to tipping point for the 11/29 deep slab instability. Overlying slab was pencil density at the minimum with obvious layers. Area had seen multiple days of explosives use and skier compaction previously this season, including the day before (1/24).