Quick report
The new snow itself presented no avalanche danger in observed terrain. It was well-bonded to the old snow surface. Mid-storm interfaces were hard to identify and produced no results in testing and no avalanches as people headed into steep terrain. The outliers might be places where graupel pooled up early in the storm and could be more reactive. A combination of sun and warming were the main drivers of danger, but the new snow may have been too dense to produce widespread loose wet. Lots of rollerballs and pinwheels, though. More wind at upper elevations was likely creating some small slabs. On the other hand, the new snow is quite dense and resistant to drifting, so would not expect to see widespread slab formation unless the wind really ramps up.
Most slopes facing the sun - and even a few that didn't - were covered with rollerballs, but loose wet avalanches were fewer than expected up to early afternoon. Wind drifted features were generally unreactive except for small unsupported cornices. Even those needed a few good kicks to get to release.Weather
- Cloud Cover
- few
- Wind Loading
- previous
- Recent Snowfall
- 50
- Snow Avail For Transport
- small smounts
Sun filtered through spotty high clouds that increased in coverage in the afternoon. Light southerly winds kept warming in check in exposed locations, at least until 13:45. More pronounced wind loading was visible high on Shuksan and occasionally on other peaks around the Baker BC.
Snowpack
40-65cm of 4F to P new snow. 2-4cm graupel layer at new-old interface did not produce consistent or sudden results. A mix of thinner DF and RG layers around a crust, all above the 1F rain-affected layer from Saturday. Test results were remarkable in two locations. The ski pen was 10cm, but the boot pen was all the way down to the rain layer. Southerly aspects wetting but northerly staying dry, at least until 13:35.
Avalanche
A variety of loose wet avalanches to D2 on southerly aspects, but sporadic in distribution. Many slopes that often produce wet avalanches just had piles of rollerballs. Wet activity could have increased later in the day with warmer temperatures. One very large slab avalanche visible on the southwest side of Shuksan at 7500' (no photo). It had fresh-looking debris, so it either released naturally during the storm or early this morning with wind-loading. Another slab avalanche was on the south side of Sefrit, triggered by loose wet from above. No human-triggered avalanches were observed.