Widespread Avalanche Activity on Andesite Ridge

A mix of rain and snow accompanied by strong winds greeted us at the trailhead for Andesite Peak. We geared up, started up the ridge, and felt the temperatures cooling off. Precipitation turned to all snow within minutes of putting on our skis. The snow surface started to refreeze and quickly became supportable. We could feel about a foot of wet snow below the refrozen rain crust. A thin mix of dense snow and graupel dusted the top of the crust in sheltered areas. Quick tests and hand pits indicated the dense wet snow had not bonded well to the snow below it. 

We stayed on the ridge in low-angle terrain away from steeper slopes, but we got views of some avalanche terrain. We saw debris at the base of several slopes and mostly filled-in crowns at the top of many slopes. These avalanches looked like they occurred last night and had since filled in with blowing and wet snow. We saw some in below treeline terrain and some in near treeline terrain. Some were wind slabs, and some looked more like wet slabs. All of them were on steep NE-E facing slopes. The largest avalanche we saw occurred near the top of Andesite Ridge. In this exposed area, the rain crust had no snow on it. This slippery crust made skinning difficult, so I stepped off my skis on the ridge to get a better view of the avalanche. As I stepped through the rain crust on the ridge, a section of cornice 20-30 ft away broke loose. Cornice pieces the size of a minivan fell onto the slope that had avalanched and triggered another avalanche across the entire slope. It was about 18 to 24 inches deep and about 180 ft. wide. It ran down into the trees below and even took out a couple of smaller trees.  

On the way out, we continued utilizing low-angle terrain and carefully avoided being under steep slopes. The weather continued to cool during our tour. the winds and snowfall also decreased during our tour.