Southern Ruby Range

Above treeline: persistent slab structure still exists in some areas, but is patchier now because of previous avalanche events, wind events, and melt-freeze events.  With an eye for reading wind erosion and old avalanche activity, we felt comfortable moving through some steeper terrain and avoiding a few features of concern.  In short, the snowpack is highly variable and quiet underfoot.

Targeting the extent of strengthening in the upper snowpack from recent warmups on southerlies:  On slopes less than 35 degrees, the snowpack structure was mostly dry and you could find persistent slab structure on previously windloaded SE or SW aspects.  Above 35 degrees, the last few warmups have added several crust layers up to a few cm thick, offering some strength to the upper snowpack.  Our impression was to get an avalanche on southerlies, you'd need to find a combination of heavily drifted onto a colder terrain feature, which we expect is isolated throughout most of the Ruby Range.  

A pit on a suspect-looking east facing feature at 12,000', showed a 2.5' hard slab (1F to P) over slightly rounding facets (4F-, 1.5-2.0 mm).  An ECT produced propagating results after additional loading steps (32 hits).  

In steep terrain, snow surfaces are mix of melt freeze crusts or crust/facet/crust combos on southerlies, and windboard or softer, faceting sastrugi on northerlies.