Andesite Peak

We went to Andesite Peak today. We observed easy to trigger wet loose avalanches, increasing storm slab instability, and rising snow levels. New snow amounts in this area were around 8 inches. There was a thin rain crust in mid height within the new snow indicating a snow-rain-snow progression over the past 24 hours. Wet loose avalanches were failing on this rain crust within the new snow.

Storm slabs were present with numerous hand pits easily identifying a dense slab of 4F to 1F hard new snow sitting on top of F hard near surface facets at or just below the old/new snow interface. We noted the presence of this near surface facet weak layer in numerous locations near treeline and below treeline across W-NW-N-NE-E aspects. While we did not trigger any cracking on this layer. Low scoring ECTP results were very repeatable on this layer. It seemed that the new snow load had not quite reached the critical tipping point on stability. With ongoing loading from new snow and rain, it seemed highly likely that avalanches would occur on this layer either later today or tonight.

We observed snow level rising from 7,100' at 9:30 am to 7,500' at 12:30 pm. The vertical profiler at Colfax, CA measured rapidly rising snow levels occurring as the afternoon portion of today’s storm moved towards the Sierra Crest.

New storm slab formation of new snow slab on top of near surface facets. ECT scores ranging from ECTP-5 to ECTP-12 were very repeatable in three separate testpits on near treeline and below treeline N, NE, and W aspect terrain between 7,600' and 8,100'.