Northern San Juan

Temperatures began in the 20s but quickly climbed to above freezing. Moderate southwest winds and the occasional strong gust kept things cool above tree line. But below the tree line, the snowpack warmed quickly and was moist on the surface by mid-morning. Partly cloudy skies cleared to mostly sunny skies.

The snowpack is transitioning towards spring conditions on most sunny slopes at lower elevations, with a supportive crust that softened under warm sunny skies and lots of evidence of liquid water moving through the snowpack. Digging down on a sunny east-facing slope below treeline, I found moist and rounding snow grains throughout the entire snowpack. But near and above treeline, it's a different story, with a cold winter snowpack and stiff midpack slabs sitting over weaker snow near the ground. In a pit near treeline, I was able to get propagating failures below these stiff midpack slabs on old weak faceted snow (notably, failures happened below our 2/11 PWL). Above treeline, the new snow has stiffened into a Pencil-hard slab and I was unable to produce any collapses or failures. Here, the entire upper snowpack was stiff and well-adhered together. The impacts of recent wind and warm weather were abundant above treeline, with some punchy windskins, zipper melt-freeze crusts, and some soft suportable wind-ripple.