Wind Slabs and New Snow on Andesite Peak

We found about 4 inches of new snow at the trailhead with 6 inches of new snow higher on Andesite Peak. This new snow was more dense at bottom and lighter near the top. It rested on top of a thin melt-freeze crust with a deep layer of soft wet snow below the crust. We only saw minor cracking in the new snow in the sheltered near and below treeline terrain. Our test pits also showed decent bonding between the new snow and the old melt-freeze crust.

When we reached the upper half of Andesite Peak, we saw signs of widespread wind-loading: blowing snow, newly formed cornices, and ripples in the snow surface. Small test slopes started to crack when we stepped on them. The cornices broke easily when we stomped a few feet away from their edges. Ski kicks on one wind-loaded test slope caused a 1-1.5 ft deep wind slab failure. We did not see any natural avalanches on large wind-loaded slopes, and we did not venture onto those slopes to test them.

The weather calmed down during our trip. At first, it was snowing lightly with consistently strong winds. By 10 am, snowfall had all but ceased. The winds remained strong enough to blow snow into the afternoon.