Southern San Juan

Avalanche

Chris Bilbrey · Feb 11, 2020 · Southern San Juan

Weather

Overcast skies and light snow showers didn't amount to any measurable accumulations during the day. Winds we're light to non-existent and didn't contribute to fresh wind slab formation in the terrain we traveled in.

Snowpack

Evidence of fresh wind-drifted slabs on north to east-facing terrain near treeline was lacking where we traveled. We did not climb above treeline, but anticipate thicker and more widespread drifting along ridge tops and in cross-loaded terrain features - new cornice growth, wind swells, and textured surfaces were visible in alpine areas. The snowpack below treeline on northerly and easterly-facing slopes keeps providing mixed results. Extended Column Test in multiple snowpits produced propagating failures below snowfall from our last two storms breaking in a faceted crust (east) and near-surface facet (northeast). Despite these concerning results, we did not observe cracking or collapsing while jumping on steep, small and non-consequential test slopes. A snowpit on a north aspect at treeline yielded non-propagating results in Extended Column Test - this near-surface facet layer was harder than at lower elevations. The snowpack in general below treeline continues to weaken but is not consistently weak from slope to slope at present time. The area near Molas Pass has received similar snowfall totals as the North San Juan, and the instability we observed today may be a product of a bigger recent load as compared to parts of the South San Juan zone further south. Snow depths below treeline were around 150 cm and old, facets/ depth hoar at the ground are rounding with hardness around 1F.

Avalanche

None observed today that we're new and not already recorded.