Southern San Juan
SnowpackChris Bilbrey · Dec 31, 2019 · Southern San Juan
Weather
What a way to end 2019...blue skies, plethora of Vitamin D, and light winds keeping temperatures at bay.
Snowpack
We found overall good stability on multiple aspects. Southerly-facing slopes below treeline started to warm with today's sunshine and developed a thin zipper crust on the surface by the afternoon. Shady slopes remained cold and dry with surface snow beginning to facet. Found fresh surface hoar in wind-sheltered areas. Many alpine slopes have been scoured, sculpted, or drifted by the wind. Wind damage not as extensive as areas further west and north. Found a 3 to 5 cm soft, breakable slab in exposed terrain but it quickly diminished below ridges. The snowpack is deep on northerly-facing slopes and range from 1.5-2 meters deep. Only observed non-propagating failures in our northeast snowpit. Southerly and west-facing slopes are much shallower (generally around 1 meter or less) and have a more complex snow structure. We observed moderate and hard force propagating results in long-column test breaking in facets at the ground on a southeast and southwest snowpit. Fractures were dirty and non-planar. Stiff, overlying slabs above weaker snow makes triggering more difficult and these shallow locations seem isolated in the bigger terrain picture. No cracking or collapses today.