Northern San Juan

Avalanche

Colin Mitchell · Mar 6, 2020 · Northern San Juan

Weather

Warm and sunny day with very light winds. High thin clouds increased during the day, but were doing little to stop the radiation.

Snowpack

Overall we found a deep and solid snowpack in this area. Average HS was around 160 cm. Below treeline, the snow had a stout, supportable melt freeze crust on southerly aspects. Only slopes facing due north had soft snow on the surface. Near treeline, crusts were less pronounced but existed in many areas. Northerly-facing slopes in the near and above-treeline elevation bands, had a deep, well-consolidated snowpack with a few inches of near-surface facets at the top. We did find a layer of buried facets down about 30 cms that was reactive in a compression test, but would not propagate with an ECT. This is probably the layer that has been producing isolated small slab avalanches this week, but was not an issue where we traveled. We spotted several wet loose slides below treeline on SE-SW aspects. These were small and mostly harmless, but one of them stepped down into weak, older snow and ran to the ground. We will likely see more of these gouging into very weak below treeline snow as we move towards spring.

Avalanche

We saw a few small loose wet slides coming from rocky, southerly facing slopes below treelind. One of them stepped down into weaker snow at the ground.