Avalanche: Douglas Island

Location: Banana Chute

Route & General Observations

See avalanche details

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger SnowboarderAvalanche Type Soft Slab
Aspect SoutheastElevation 3000ft
Slope Angle 38degCrown Depth 8in
Width 40ftVertical Run 600ft
Near Miss / Accident Details
Avalanche Details

Took the standard approach from the west to reach the southeast facing banana chute. We noted limited signs of instability on our tour, but did note obvious greenhouse effect radiation on the ridge that was rapidly warming the snow surface and increasing cohesion in the soft storm snow. A hand pit at the top of the chute failed while isolating a column, ~20cm down on top of a thin crust layer. This crust layer was not observed on the approach from the west, and likely formed on March 20th. Performed a ski cut after the rollover into the main run which did not produce a result. The avalanche was triggered on the 3rd or 4th turn. The fracture occured at the feet of the rider, and they were able to quickly reach higher ground on the side of the chute, no one was caught. The avalanche ran a considerable distance, but failed to reach all the way to the valley bottom.

Events of the day

To recap our decision making: we were fairly commited to skiing the chute and the skiing conditions were great ("human factors"). Based on our observations, we certainly felt a human triggered avalanche was possible. We agreed that the terrain in the chute provided lots of places to escape should an avalanche occur. The steep side-walls of the line meant higher ground was always available. Based on our understanding of the avalanche problem and the terrain, we made what we feel was an informed decision to accept the risk of skiing the slope. Fortunately no one was caught.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Observer Comments

Rapid warming of the snow surface that increased cohesion of the storm snow, handpit failed when isolating the column. At lower elevations on the exit, we also noted touchy loose wet avalanches in steep terrain, and the trees were shedding snow in the forest.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Overcast, Temp 31F, Snow S-1, calm wind

Photos & Video
Please upload photos below. Maximum of 5 megabytes per image. Click here for help on resizing images. If you are having trouble uploading please email images separately to staff.