Avalanche: Turnagain

Location: Seattle Ridge - Main Bowl up to 2,800'

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 NaturalAvalanche Type0
Aspect West NorthwestElevation 2300ft
Slope AngleunknownCrown Depth 24in
Width 300ftVertical Run 300ft
Avalanche Details

Natural trigger during rapid warming. Unknown weak layer

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

I did not experience collapsing or cracking. The party close to the avalanche reported collapsing and cracking (see Fennnell’s ob for more)

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

Warm, cloudy, no wind

Snow surface

Snow surface was close to isothermal between 1,000-2,000’ upon descent at 2pm. Generally damp surface snow up to 2,400’.


Dug one pit on the skier’s left side of Main Bowl, 2,800’, ENE aspect. Test results showed high strength that went down the longer the pit wall was exposed to warm air and sun. High propagation potential, poor structure and moderate friction. Weak layer in this location is large surface hoar (8mm) mixed in with old facets 85 cm down sitting on a “concrete like”crust. See pit profile for more detail.

Photos & Video
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