It is very likely this slide was remotely triggered while the party was on the ridge and the slope was out of view. Follow-up with a member of the party reported they felt a collapse while they were on the ridge.
Avalanche: Turnagain
Location: Seattle Ridge
Lots of wind loading below Seattle Ridge. We were skinning through what later became the slidepath and noticed about 3 feet of soft wind loaded snow. At the top of our next run, we saw that the slope had ripped.
Forecaster Comments
| Trigger | Natural | Remote Trigger | 0 |
| Avalanche Type | 0 | Aspect | Northwest |
| Elevation | 2100ft | Slope Angle | 35deg |
| Crown Depth | 3ft | Width | 600ft |
| Vertical Run | 300ft |
Avalanche Details
Very soft slab.
Obvious signs of instability
| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | Yes |
| Cracking (Shooting cracks)? | Yes |
Observer Comments
We were able to see the recent avalanche off of Basketball (Magnum/Taylor Pass), which is a very similar aspect to this avalanche.
We saw some cracks open up on the apex of several convex terrain features nearby.
We saw some smaller sloughs in the area as well and got some whoomping on the flats of the ridge itself.
Weather
It was warm and the cracking, whoomping, and sliding all occurred at the warmest point in the day, right after the temperature seemed to climb a bit.
Snow surface
Soft, wind-deposited powder.
The slidepath viewed from an adjacent basin in Seattle Creek.