Observation Date: 02/12/2021
Cold. -20 to -30 at night, 0 during the day. Calm to light winds picking up to moderate on the morning of the 12th. Sunny to partial cloud cover.
New Snow: No New Snow
Saw 2 small avalanches that run during the storm. D1.5-R1 soft slab ran on 40 degrees slopes on isolated rock features that were windloaded. Ran in the new storm snow at 7500′.
We spent 3 days and 2 nights in the southern swan and had a great time skiing the new snow. We found a very spatially variable snowpack.
-Around 6800’ we found an HS of 180. The 13th crust was about 80cm down and eggshell thick with facets at the bottom of the snowpack.
-Above 7000’ on S to NE windloaded terrain we found a HS of 270cm. In our pit we had F hard transition smoothly to 4F in the top 1.5M of the snowpack, got an ECT-X.
-Ski cut many small wind loaded test slopes on S to NE aspects and had no cracking.
-Saw two small avalanches that ran some time during the storm. Not sure how big the crowns were because they were almost filled in. Both were D1.5-R1 and broke on steep isolated rock outcroppings.
-Our group had one large collapse at ridge top on an E aspect. E facing terrain was scoured and the snowpack at ridge top was very thin.
-Noted several large cornice failures , car to house sized. None produced avalanches on the slopes below.
-Winds shifted on our last morning, creating new wind slabs on W facing terrain at ridge tops.
-Saw new surface hoar growth. Crystals were small but on all aspects.
Observer: Jeremy Primmer