Northern San Juan

Snowpack

Krista Beyer · Dec 17, 2024 · Northern San Juan

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Weather

Winds shifted direction mid-morning from southwest to west. average wind speeds at ridgeline were between 20 and 30 mph. East facing slopes below ridgeline offered calm winds. Temperatures hit freezing level at 11,000 feet.

Snowpack

Wind slab thickness and firmness vary significantly across terrain features. On a previously drifted northeast slope near treeline we found two wind slabs in the top 25cm of the snowpack. Both wind slabs sit above weak facets and will be layers of concern with additional snow loading. In the areas we travelled the surface wind-drifted snow was not thick or strong enough to be of concern beyond impacting the quality of surface conditions. The buried wind slab is thicker and firmer, but failed to produce propagating results during tests. Below treeline snow is cohesionless but supportable on most slopes. Trap-door conditions were limited to shallow areas near rocks or shrubs. Loose-dry surface sluffs were less reactive than observed in previous days. The snowpack has lost noticeable mass below treeline during the past week.