Northern San Juan
SnowpackKrista Beyer · Feb 11, 2025 · Northern San Juan
Weather
Strong southwest winds continue. Temperatures have dropped back down to hard overnight freezes and below-freezing daytime temperatures. Evidence of the warm to cold temperature swing can be experienced firsthand on Silverton's ice-covered streets.
Snowpack
The surface of the snowpack shows evidence of last week's warm temperatures but continues to have faceted grains in the upper pack. Beneath the surface, preserved facets and depth hoar sit waiting for a load to re-awaken our Persistent Weak Layer from the December drought layer. There are weak layers higher up in the snowpack on some slopes associated with crust development on the slopes we traveled and wind slab development on others. We may see failures in these weak layers before we see failures on our deeper pre-Christmas drought layer, but the deeper pre-Christmas snow remains our Layer of Concern for avalanches that break deeper. I dug in a wind-drifted area to look for strong over weak combinations and received fairly unexciting test results. Sheltered below-treeline skiing confirmed that surfaces on north aspects are weak and faceted and will likely be the first to fail with a new snow load along with near treeline start zones actively loading on north to northeast through east slopes.