Southern San Juan
AvalancheChris Bilbrey · Feb 4, 2023 · Southern San Juan
Weather
Nice sunny day with a steady west wind along ridgetops. The wind kept the crust firm on southerly-facing slopes at upper elevations.
Snowpack
We traveled around the compass through all elevation bands and found a nearly right-side up/ uniform upper snowpack with a stout mid-body slab (mostly 1F to P- hardness with probe feel). Southerly aspects had a robust surface crust that ranged 1 to 2 inches with faceting immediately below. The snow surface on the east and west aspects was still cold and resisting the warm-up well. Those aspects below the treeline softened today but never got gloppy, but by afternoon, east-facing slopes had a zipper crust on the surface. The snow surface on northerly-facing slopes at all elevations remains cold and winter-like. The most recent snowfall from January 31 ranged from 6 to 8 inches and is already faceting quickly near the treeline. Above 12,000 feet, we encountered a variety of surface conditions that ranged from creamy, wind-pressed snow to firm wind-board adjacent to textured, wind-sheltered surfaces. Numerous hard wind layers exist throughout the upper snowpack on northwest and north aspects. Probing across slopes in the alpine, it was difficult to discern obvious softer/ weaker snow layers in the top meter of the snowpack. Digging down, we could identify thin near-surface facet layers and faceted crust, but these layers were unreactive and appear to lack enough of a load above to pose many hazards at present - but something to remember during future loading events. November drought facets were consistently buried between 165 and 200 cm below.
Avalanche
We observed a lot of fresh Loose Dry avalanche activity that likely occurred on February 1. We also spotted numerous older, large crown lines throughout the alpine terrain that were mostly filled back in. These likely ran between the New Year and mid-January. Most crowns and debris piles were too aged to accurately code, but we counted around a dozen or more size 2-2.5 crowns mostly on northwest through north to east aspects above the treeline. Additionally, all the big paths above CR 124 hit the road and lots of debris fills the main creek from adjacent paths that do not impact CR 124.