|Location:||Seattle Ridge - Main Bowl up to 2,800'|
|Trigger||Natural||Avalanche Type||Aspect||West Northwest|
|Elevation||2300ft||Slope Angle||unknown||Crown Depth||24in|
Natural trigger during rapid warming. Unknown weak layer
Obvious signs of instability
|Recent Avalanches?||Yes||Collapsing (Whumphing)?||No||Cracking (Shooting cracks)?||No|
I did not experience collapsing or cracking. The party close to the avalanche reported collapsing and cracking (see Fennnell’s ob for more)
Warm, cloudy, no wind
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.