Southern San Juan
AvalancheChris Bilbrey · Mar 25, 2024 · Southern San Juan
Weather
Mix of clouds, light snow showers, and sun. Moderate to strong northerly wind moving snow at upper elevations. These winds mixed into lower elevations pressing the snow surface into a denser surface slab.
Snowpack
Inverted storm slabs were reactive in ECTs on an east-northeast aspect around 11,200 feet, and on a south aspect at 11,600 feet. Test failed with 5 taps or less in both snowpits. We also observed propagating failures in ECTs below a faceted crust with 18 taps in our below treeline (11,200 feet) snowpit. The crust here was 1F-, degrading, and near-surface facets below were dry (couldn't make a snowball) and angular (0.5-1 mm). This interface sits below the latest round of snowfall, but no audible collapsing noted on our travels. The buried crust on southerly slopes was more robust and faceting below not as advanced - these grains were also trending toward moist versus dry on shady slopes at similar and lower elevations. Sunny skies in the afternoon contributed to rapid settling and consolidation of the storm snow, making it a bit more inverted than on shady slopes and as compared to earlier in the day. Descending north to east-facing slopes near and below treeline, we observed appetizer-sized platters break apart on the surface, but no slab release in terrain around 35 degrees or less steep. We avoided above treeline, wind-loaded start zones due to snowfall depth and inverted nature of surface slabs.
Avalanche
No natural avalanche activity from the recent storm cycle. Older-looking avalanche debris that likely ran around the St Patrick's Day storm event.