Wet Slab Avalanche in Third Creek

Fourth Skier onto slope in lower Third Creek drainage in 32 degree terrain triggered a wet slab avalanche and exited off the side of the slide, 60 feet wide by 12 inches deep, slab slid into lower angle slope collecting snow past the staunch wall and created a sizeable pile up moving down slope. At one point the moving piled reached about 4 to 5 feet deep before spreading out. Total slide length about 400 feet over 150-200 vertical.  As the slide came alongside the group standing off to the side of the path it triggered an audible whumpf and collapse in the snowpack where we were standing on 20 degree terrain.  Snow pack was softening at this time of day (12:30) and surface refreeze was collapsing in some heavily weighted turns and skis were penetrating 4 inches into the subsurface wet snow. The slab was new snow not consolidated from the previous week running on the old/new snow interface. Earlier in the morning skiing was excellent with good surface melt corn on same aspects. Clouds had covered the sun about 30 minutes before and cross wind was moderate and the cool on slope.

Party exited slope to lower angle terrain and skied out to the car.