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Avalanche: Turnagain

Location: Tincan

Date:
Observer:
Route & General Observations

Standard route up Tincan to Todd’s Bowl. Noticed a recent slab avalanche on SE aspect of Seattle Ridge, an area known as Little Sweden. The slide covered several snowmachine tracks. This was confirmed in the evening┬áto be triggered by a snowmachiner around 12:30pm 3/11. No one caught.

Avalanche Details
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Trigger NaturalAvalanche Type Unknown
Aspect UnknownElevationunknown
Slope AngleunknownCrown Depthunknown
WidthunknownVertical Rununknown
Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?No
Cracking (Shooting cracks)?No
Observer Comments

Recent slab avalanche on SE aspect of Seattle Ridge

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

Clear and sunny
Temps in the teens F - and noticeably cooler in shaded zones
Calms winds

Snow surface

Variable surfaces. Hard pack/sastrugi along ridges, faceted "recycled" powder in protected areas below ridge lines in the alpine.
Below 2500' 4-6" of loose faceted snow.
Below 1400' surface hoar 4-6mm in size sitting on 4-6" loose faceted snow.

*2cm sun crust was found on steep South facing slopes at all aspects.

Snowpack

Probed around in starting zone of Todd's Bowl and height of snow ranged from 180cm to 280cm.

Dug a quick test pit at 3500' in Todds, HS=245cm, 42 degree slope, N aspect - Pit height was 115cm and was right side up. The surface had a 1cm wind crust capping 4F hard snow. The top 35cm had varying layers of 4F to 1F hard snow. Below this was all Pencil hard snow. Compression Tests failed 20cm below the surface with moderate force, and failed again 35cm below the surface with strong force. Both failed on 0.5-1mm near surface facets, but in both cases the slab broke into pieces.

Photos & Video
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