Sunday, March 24, 2019 - 1:45pm
Report of skier triggered small windslab avalanche in western couloir of Matterhorn peak. R2-D1.5. Group of 4 skiers booted up the couloir, spacing themselves out when they arrived to a concerning area of thin denser windslab over softer snow near the top. The group made it to the top without incident, then the first skier down on his 4th-5th turn hit the edge of a wind slab pocket, triggering the slab next to him. The 15-25cm deep pocket was about 30ft wide and ran the length of the couloir and fanned out in the apron at the bottom covering up two swtichbacks of the skintrack (See attached photos provided by party in couloir). Fortunately no one was in the gut of the couloir or below on the skintrack. The debris at the bottom was not deep enough for a burial, but it could have taken someone for a good ride. Slab was composed of ~10cm of 4finger hard windslab ontop of ~15cm softer fist plus snow, which failed ontop of pencil hard old snow (see attached photo). Everyone in the party skied down after without further incident.
Morning was quite windy, but calmed dramatically by the afternoon, with light gusts over ridgetops, with little additional visible snow transport. Sunshine, few clouds, light haze.