Vail & Summit County
AvalancheKreston Rohrig · Feb 6, 2020 · Vail & Summit County
Weather
The storm raged on as expected. I never made it to upper elevations, but winds below treeline were moderate at best. Snowfall rates were easily an inch an hour if not two at times. It was a socked in full-on winter storm.
Snowpack
There was near 8 inches of new snow by the time we left the pass, sitting on another 8 inches of snow from the past few days. The most problematic thing I found was all this recent storm snow now sits on layers of buried near surface facets. I easily initiated some small sluffs and storm slabs on steeper slopes that cleaned out the new snow. My other goal was to look at and compare the snowpack in areas that slid back in the mid-December cycle to areas that haven't. The contrast is significant. Areas that have not avalanched, have a much deeper (175-200cm) snowpack in this part of the zone, compared to the 100-120cm snowpack in the areas that previously slid. In these paths that ripped out earlier, the snowpack was incredibly weak from top to bottom and was comprised of fist hard facets. These areas will not do well with the massive amounts of snow coming tonight and tomorrow and may be some of the first to fail.
Avalanche
I intentionally triggered a small storm slab avalanche on a steeper slope to see how reactive or poor the bonding is to older layers. Buried near surface facets sit below the recent storm snow and will easily fail with more weight or a human trigger. The slab was only 6-8" deep at the time, but this was early in the tour.