Copper Mountain Avalanche

Skier triggered a windslab while skinning along a narrow alpine ridge. Start zone flanks had several boulders along it and the crown tappered off from 40cm to 0cm as it reached high treeline. As the volume reached high treeline the lower path released to ground (start zone did not) and we believe the avalanche went full path (although hard to know for sure due to bad vis and position on the ridge). The avalanche also had enough powder to jump over at least one high treeline rib. We could hear trees snapping for some time as the powder cloud looked to reach the fan below, which lead us to believe it went full path with some power intact. Was unwilling to investigate the start zone bed surface due to terrain and risk of it too releasing to ground.