Snow-biker remotely triggered this avalanche in the Bennett Pass area. They reported seeing cracks shooting out from their bike and watching the slope slide in front of them. The interface it failed on correlates with the new/old interface and could be a likely spot where the surface hoar was living. That said, I wasn't there and the reporting party didn't get a closer look than these pictures, so hard saying if persistent grains was the culprit or not.
SS-AMr-R3-D1.5-I