Lakes Basin

Our goals today were to look for new wind slabs, and continue to survey the presence or lack of a persistent slab problem. 

We observed small amounts of blowing snow, and moderate amounts of previously blown snow. Most of the snow that we found was still cold and in an unconsolidated state. Due east slopes were getting moist and sticky in the mid-February sun.

We dug in on a northeast slope at 10000 feet to look at snowpack structure and test the buried weak layers, and again found poor structure but an absence of a slab in this location.

We then went over to take a closer look at a few avalanches from 2/11 on the East Slope. A hasty crown profile, neighboring structure, and interesting shape and character all lead us to believe that these three adjacent avalanches were persistent slabs that ran on the 2/10 facets. They were also slightly larger than the distant photos suggest.

We found pleasant skiing on protected norths, and sticky skiing on anything tipped towards the sun.

There's 20 to 40 cm of settled new snow below 10000 feet in the Lakes Basin. This snow is mostly still low-density and unconsolidated.

Structure is poor, but signs of instability were few. 

We dug on a northeast aspect at 10000 feet and found 40cm of new snow on top of 30cm of large facets. 

An ECT showed low propensity for propagation, with an arrested collapse down 20cm from the surface (ECTN12).

Some snow had obviously been drifted in the past 24 hours, but we saw no evidence of natural wind slab avalanches.

We investigated several adjacent avalanches first observed on 2/11. We felt confident concluding that all three were similar D1.5 persistent slab avalanches that failed on the well-advertised 2/10 near-surface facets. See attached avalanche observation for more information.