Northern San Juan
AvalancheKaylee Walden · May 22, 2019 · Northern San Juan
Weather
Partly cloudy eventually turning to overcast, snowing and low vis. Gentle breeze to the SE. Temp hovered around 30 degrees throughout the tour.
Snowpack
South-facing, protected couloir above treeline, at approx. 11,800’. New snow overnight in this zone appeared to total an average of 6â€, with another 12†the night before. We noticed an interface where the snow had notably warmed between those two storm events, a melt-freeze crust beneath the storm snow, and a dust layer directly below that. We dug a quick hand-pit on our N-Facing line and noticed the melt-freeze crust was not as pronounced.
Avalanche
With stomping off a small cornice, we caused the storm slab, ~8†deep here, to break the width of a small couloir, about 300’ long and 25’ wide. It ran the length into the basin below on the melt-freeze crust that had been insulated by the new snow and was considerably wetter/warmer than the storm snow on top of it. We did not encounter the same problem in our second lap, which was North Facing. Beneath the melt-freeze crust we noticed a dust layer as well. This interface could be problematic; if it hadn’t been anticipated, the small slide we caused could have been consequential in bigger/more committing terrain. We skied the line after it “cleared out†and noted the snow beneath was considerably warmer and sticky.