Quick report
- Collapsing
- isolated
Over the past two days on Teton Pass, we have observed propagation in several ECT's on the same PWL. I checked out the crown from the reported Dec 10th avalanche in Avy Bowl. HS 129cm, bed surface 50cm up from GND, rain crust 95cm up, overall crown depth 79cm or approx 2.5 feet. Isolated collapsing along the plateau above the Bear Claw.
Weather
- Air Temp
- 25deg
- Cloud Cover
- clear
- Wind Loading
- none
- Rain Elevation
- N/A
- Recent Snowfall
- No
- Snow Avail For Transport
- small smounts
While the max temp was 25deg, the solar input was strong all day. Impressive surface hoar formation up to 2cm observed over the past two days, especially in protected yet open meadows. Winds were moderate out of the the NE yesterday, shifting to a W/SW flow today.
Snowpack
Very poor structure overall, with better strength in stability tests where the snowpack is deeper. There are two primary layers of concern. A rain crust in the upper portion of the snowpack is less reactive than the facets below a deteriorating crust lower in the snowpack. We concluded that the Dec 10th reported avalanche in Avy Bowl occurred on these facets and propagation in our stability tests confirms this layer of concern. The facets are 1-2.5mm in size and located below a decomposing crust. While stability tests in deeper snowpits had more stubborn propagation results, the facets are still highly reactive, demonstrated to us by collapsing in the plateau above the Claw.