Southern San Juan
SnowpackChris Bilbrey Jeff Davis · Dec 15, 2020 · Southern San Juan
Weather
A tad bit windy for our liking. None-the-less, a cold and beautiful day in the mountains. Northwest winds finally died down on our exit around 2 pm.
Snowpack
Today's strong northwest winds helped redistribute recent snowfall leaving some slopes scoured down to the old snow surface while forming soft wind-slabs on leeward terrain. Wind damage was more widespread near and above treeline but swirling winds below treeline left their mark. These slabs were reactive to ski pressure and we observed numerous audible collapses with long running cracks. Stability test produced propagating failures in a softer layer of decomposing fragments below fresh wind-slabs and in facets (1-3 mm) lurking at the ground below a stiff 1F mid-pack. In wind-sheltered areas, recent storm slabs remain soft, but sit above a weak, fully faceted lower snowpack. This soft slab continued to fail with easy force in compression test but the overlying slab was too soft to propagate a failure in Extended Column Test. Many south and southeast-facing alpine slopes now have the best snow cover in some time. Despite a lack of buried weak snow, drifts on southerly-facing slopes around 2 feet deep can be found below ridge lines and in cross-loaded gullies.