While skinning in 15 degree terrain at 2200 m we heard a massive whumpf. Several seconds later we remotely triggered two size 2 avalanches and two size 2.5 from 150-400 m away on a NE aspect at 2300 m in 35-40 degree terrain, below ridgeline. The closest, steepest slide initially failed in the persistent weak layer down 30-40 cm which then stepped down to the deep persistent layer about 80-100 cm down. The three other slides did not have visible step down crowns and seemed to just fail on the deep persistent slab.
A test pit nearby with a total snow depth of 115 cm gave consistent, moderate, compression test results down 30 cm on facets but the fracture character was resistant planar. We got hard, sudden collapse results down 85 cm on well developed depth hoar. This layer tested positive for propagation (ECTP23).
We also likely remoted a large size 1 in unskiable terrain at 2100 m from 80 m away although we heard no whumpf.
Skies were overcast yesterday and today with alpine temps below freezing, but wind transport was visible at ridge top today before the remotes.