Rounding Surface Hoar on Rubicon

Observations on Rubicon Peak focused on determining how the buried surface hoar layer has changed since Jan. 20th. 7 days ago, this buried weak layer remained large, angular, and tests targeting the surface hoar layer showed consistent unstable results. Today in a similar location, the surface hoar had rounded, become much stronger, and tests targeting this layer did not show any signs of instability (see pit profile and photo for more details). Snowpit data and general observations showed a strong well consolidated snowpack with a few inches of softer snow on the surface. Near the summit of Rubicon wind affected snow surfaces like firm wind packed snow existed. No signs of instability were observed in these wind affected areas, nor did we notice any blowing snow along the ridgelines in the Desolation Wilderness.  Below 7600 ft. a firm rain crust existed below the few inches of softer snow on the surface. 

Photo: Comparison between the buried surface hoar between Jan. 20 and today (Jan. 27).