Northern San Juan

Avalanche

Jeremy Yanko · Feb 26, 2022 · Northern San Juan

Weather

Cold morning, warm overhead sun by midday but northerly winds kept the ambient temp moderated.

Snowpack

Still finding collapsing and cracking by adding weight to the new slab over weak layer/s, whether in the flats or near wind-drifted features that are north of west where a collapsible crust sits over large faceted grains. A trace of new snow fell overnight in this area on top of a recently developed 1cm crust lens on west/southwest facing slopes between 10k-11k. The recent storm and strong southwesterly winds left little uniformity near treeline on West facing aspects. Anywhere from 0cm to 45cm of settled snow was left in the wake of the President's Day storm cycle at this site. Some S/SW slopes are scoured back to old 5cm melt-freeze crust or recently loaded up against rock features. The isolated terrain with wind loading on the SW aspect showed no signs of instability and moderate failures via multiple hand shear tests on the new/old interface. Just out of treeline at 11'600ft, found fair-good stability on a due west aspect with moderate to hard snowpack test scores and no signs of instability. The new slab is wind-pressed and yielded decent bonding on the old 1F 8cm crust interface.

Avalanche

Just south of Middleton and above CR2, 2 natural slides estimated to have run 2/23 out of the "porcupine group" both of which started out of steep rocky cross loaded features facing N/NW. Avalanches previously coded on 2/24. 37.84565 -107.57555