Southern San Juan
AvalancheChris Bilbrey · Mar 11, 2024 · Southern San Juan
Weather
Mix of sun and high thin clouds in the morning. Mostly sunny skies in the afternoon. Moderate southwest wind with limited snow transport thanks to robust crust and lack of dry snow on sunny slopes.
Snowpack
The great burnout is happening below 10,000 feet. Creeks are starting to fill, waterfalls opening up, and large swaths of east through south to west-facing slopes have more vegetative cover than snow. Higher up, winter still hangs on. The top half-inch to inch of the snow surface on sunny slopes softened up to about 11,500 feet. Above that, wind and cooler temperatures kept the snow surface firm. While booting up a southerly-facing alpine slope, we punched around 8 inches deep into cohesionless snow below a crust. East and west-facing slopes above treeline have a less robust crust, and softened enough for ski edges to grab. Northerly slopes at all elevation bands still harbor cold, dry snow - but northerly aspects below 10,000 feet are starting to loose the prolonged warmth battle. No cracking or collapsing across elevation bands and aspects. Boot penetration on northerly aspects was around 6 to 8 inches. Probing around various aspects and elevations yielded mostly homogenous layering in the upper snowpack.
Avalanche
Spotted one older avalanche that likely ran during the early-February cycle and filled in Basin Creek. Numerous shallow, Storm Slab avalanches that likely ran during snowfall on March 2-3 - mostly on northerly aspects and around size 1.5, but a few 2s. They were partially covered up with the couple of inches of snowfall this week. Lots of rollerball action and small Loose Wet avalanches from last weekends warm-up confined to surface snow running above a crust. One more notable Loose Wet avalanche on a southeast aspect near treeline that broke wider and more like a slab than the rest.