Southern San Juan
SnowpackChris Bilbrey · Mar 9, 2020 · Southern San Juan
Weather
Hot out the gate! Temperatures near and above treeline were spared with a steady light wind and passing clouds. The same can't be said for below treeline areas. Those slopes once again warmed up and this quickly reduced the effects of last night's weak freeze.
Snowpack
We found 4 to 6 inches of new snow below treeline, around 8 inches as we crested the timber line, and up to 12 inches on northerly-facing, alpine slopes. Storm snow fell right-side-up and we found generally good bonding to the old snow surface in the terrain we traveled in. We observed failures in quick pits on a mid-storm layer but this interface didn't produce propagating test results in Extended Column Test (ECTs). We did observe mixed results in ECTs (ECTP x 1 & ECTN x 2) on a layer of near-surface facets below the old wind-packed surface on a northwest-facing alpine slope. No collapsing or cracking noted at this interface. A thin wind-skin on the surface in isolated terrain features did not present a hazard to our group. Near and below treeline slopes facing east through south to west were supportable in the morning after last night's weak freeze but quickly softened up and returned to a hollow, rotten state by midday - boot penetration to the ground in places. North and northeast-facing slopes below treeline continue to be the most supportable but are weak enough overall to be a concern with a big storm load.