Mainline Couloir, Blow Me Downs

First turn into Mainline Couloir (east aspect) triggered a small wind-slab that caught the skier and swept them down to the bottom of the run. The slab was fairly small (size 1) but entrained enough loose powder snow to become size 2. We found between 10-30cm of loose powder on a supportive melt/freeze layer on the way up the couloir and no slab properties. At the top there was some slabbing on climbers right that we skirted around to the left on harder snow. On decent the skier again avoided the slab but unfortunately it extended further than expected and was triggered from the side. The skier was off to the side at time of triggering but unfortunately was already turning back towards the slide and was unable to avoid it.