Upper snowpack faceting on Rubicon Peak.

We hiked the north slopes of Rubicon Peak today to look at overall snow cover distribution and upper snowpack faceting on the northerly aspect terrain above 8,500'. We started out on bare ground and began to encounter patchy snow at about 7,800'. Snow cover gradually increased to about 1 foot deep and then jumped to 2 to 2.5 feet above 8,400'. This is consistent with the accumulation pattern from the Oct 24 storm event and its associated snow levels. Since that storm, snow melt has been dramatic in any areas of sun exposure. Looking to the north vs to the south from near the summit of Rubicon Peak showed drastically different snow cover patterns on N vs S aspects as was expected.

We dug a snowpit at 8,960' on a N aspect slope in near treeline terrain. Taking a close look at the upper snowpack, there were some near surface facets just below the surface crust, similar to what has been observed on other N aspect slopes above about 8,500' or so around the forecast area. We performed a Birkeland et al. method loaded PST by creating an artificial 15 cm thick slab out of disaggregated snow and allowing it to sinter on top of the existing snowpack for 35 minutes. We then conducted the PST which scored 28/100 end on the facets just below the surface crust. More evidence that this layer is worth continued monitoring as we wait for the next significant loading event.