Southern San Juan
SnowpackChris Bilbrey Krista Beyer · Jan 4, 2024 · Southern San Juan
Weather
Obscured skies with brief moments of better visibility into higher terrain. Light to moderate snowfall with little to any wind along exposed ridgelines. Snow totals ranged 10 inches at 10,000 feet, and around 14 inches above 11,000 feet.
Snowpack
The low-density storm snow was reactive to ski pressure along the skin track. Downhill travel produced en échelon cracking within the new snow on convex rolls and small test slopes that approached 35 degrees. The lack of cohesion in the new snow failed to produce much movement beyond small sluffs. As the new snow settles in the coming days, we suspect an increase in sensitivity as the slab gains a little more cohesion. On northeast aspects, near surface faceting before the latest storm has created a very soft layer under the new load. A slick melt freeze crust sits below the new snow on east and southerly aspects and near ridgelines. Digging on an east-northeast aspect around 11,000 feet, total snow depths are approaching a meter in spots, with around 32 cm that fell in the last 24 hours. Multiple weak layers reside in the top 50 to 60 cm of the snowpack sitting above harder, rounding facet layers. These PWLs produced easy and moderate non-propagating failures in Extended Column Tests (ECT), likely from the upper snowpack being too soft to promote propagation. Notably, the basal facet layer at the ground is becoming harder, grains are rounding, and was unreactive in snowpack tests. With additional snowfall forecast over the weekend, weak layers near the surface will get tested from additional snow load.