Unstable test results

Date of Observation: 03/21/2022
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Pit digging in Evans and Elk Creek basins checking in on our persistent slab problem and looking ahead to potential wet slab weather this weekend. I targeted pits near treeline on east, southeast, and west aspects.

Observed avalanche activity: No
Weather: Scattered to broken cloud cover. Light to moderate northerly winds with a little bit of blowing snow near ridgetop.
Snowpack: No signs of instability while sledding, but I got medium and hard propagating test results on east and west aspects, respectively, under 2 to 3-foot hard slabs. Where I dug on due east and due west aspects, the slabs and the dryspell sandbox layer have remained dry, apart from the 3/5 crust and some recent thin surface crusts (See profiles below).  Two pits on SE aspects and one on an ESE aspect showed frozen percolation columns and ice lenses below the 3/5 crust and in the sandbox layer. The upper half of the slab above the 3/5 crust has remained dry.
My biggest concern if we see a significant warmup later this week is on those transition aspects (east and west) if meltwater starts draining into the sandbox layer for the first time. With drainage already established through the layer on southeast aspects, that is less of a concern, at least where I dug. On those SE aspects, there may be potential for water to pool along the 3/5 crust and cause thinner wet slab issues, although I didn’t find an unstable structure above the crust that is particularly alarming (ECTN results).