Northern San Juan
AvalancheColin Mitchell · Feb 27, 2020 · Southern San Juan
Weather
We saw a nice warm up today in the lower elevations, but it remained cool and breezy above treeline. Moderate, gusty northwest winds made it feel cooler than it was, and kept the snow surface cold.
Snowpack
Winds have really done a number on the snowpack near and above treeline in this part of the zone. Many northerly and easterly facing slopes were stripped. In other areas, wind had stiffened the snow into stout slabs. Fresh wind slabs were hard to find, seems like this weeks snow was mostly blasted off, spread out and/or sublimated. Snow surfaces near and above treeline were either wind board, or an inch or two of facets over stiff slabs. The average snow depth was around 160 cm on the slopes I traveled. I targeted a thinner area for my profile. There was an abrupt transition to a more spring-like snowpack at treeline. Below treeline east and southeast aspects had a mostly supportable melt-freeze crust with a few inches of moist to wet snow on top from earlier in the week. Below 11,000 feet, the snow surface was wet and crusting over by 2 pm.
Avalanche
I observed one crown from earlier this week on an east-facing slope just below ridgeline at around 13,000'