Northern San Juan

Snowpack

We dug a test pit on a SE aspect at 11,400'. HS 115, 31 degree slope angle. The uppermost layer was a frozen 6cm melt freeze crust. Below that was a layer cake of 1F slabs perforated by P m/f crusts. This was all sitting on 50 cm of old moist dh that was rounding off. The temperature was ~0*C throughout (isothermal), with moist snow or m/f crusts throughout. Overall the snowpack was pretty strong. Main weakness was the old moist DH at the bottom. We had failures of the whole slab on this layer on isolation x2. This indicates a potential future wet slab problem, but for now, the main concern on this aspect/elev will be how well the new snow bonds to the old snow surface. The surface m/f crust is stout and will hold a heafty load. However, surface crusts on more easterly aspects were much thinner and will not hold as much of a load before failing deeper into the snowpack (structure remains cold and weak). North facing terrain below treeline is still soft and largely either full depth cohesionless facets or has a firm midpack. The snowpack on these slopes has not proved reactive in either case. In general, the snowpack is just beginning its spring transition and the difference between aspects is becoming more pronounced.