Northern San Juan

Avalanche

Chris Dickson · Feb 14, 2025 · Northern San Juan

Weather

Heavy snowfall from 6am to around 7am, then a lull. S2 snowfall picked back up around 9am. WARM temperatures just below freezing made for soggy skinning.

Snowpack

I dug a quick pit on a north-facing treed ridgeline, which has previously seen some wind-drifting. Here I found almost 40cm (~16") of new snow that was fist-hard, with some of that including what fell on Wednesday. This area has a midpack 1-finger-hard slab over the dreaded December drought layer facets. An ECT produced a propagating result at the old/new snow interface at 13 taps, and several ECTNs within the storm snow. As mentioned earlier, there is a density change in the new snow, making it somewhat upside-down in hardness. This density change occurred sometime last night as the failure plane was within the bottom 4-6" of the new snow, with about 10" of denser snow on top. Considerable danger below treeline definitely fits well here for a Storm Slab avalanche problem that is likely to be human-triggered.

Avalanche

Numerous small natural Storm Slab avalanches, primarily on northeast and north-facing slopes below treeline. Most of these had crowns in the 6-8" range and likely failed on the mid-storm density change during peak storm intensity overnight.