Southern San Juan

Avalanche

Chris Bilbrey · Apr 29, 2024 · Southern San Juan

View on map

Weather

Partly to mostly cloudy skies till early-afternoon, then clouds slowly thinned providing longer moments of sunshine. There was a stray snow flurry or five during the morning hours. Light to moderate southwest wind with the occasional strong gust. All in all, a very pleasant day in the mountains.

Snowpack

Following the weekend storm, we found 4 inches of settled snow around 11,000 feet, up to 8 inches at treeline, and 12+ inches above treeline in leeward-facing terrain. We encountered isolated pockets of stiffer, drifted slabs with minor cracking near ridgelines - mostly small and harmless. Despite a hard, refrozen layer below the storm snow, we found good bonding on northwest, north, and northeast-facing slopes in the alpine. Improved bonding is likely a function of denser storm snow and little wind-drifting. Sunday and Monday's filtered sun and cool temperatures have allowed methodical surface softening across elevations, and limited wet snow avalanche activity. The most widespread action was in the form of rollerballs. Rocky slopes, gullies, and areas below cliffs were the most productive places, but struggled to entrain additional snow. During the morning hours, snow surfaces were moist near and below treeline, and dry above treeline on almost all aspects. By the afternoon, surface moistening moved up into the alpine (only an inch or two deep), and the snow surface had transitioned to wet below about 11,000 feet - very sticky on the ski out the road. The slower than expected warm-up has likely reduced the large-scale shed cycle. Once more of the storm snow gets wet from more sun and warmth, small rider-triggered wet slides remain a potential. Although, we expect it'll take many more non-freezing nights to soften upper snowpack crusts for wet slides to gouge deeper.

Avalanche

We triggered a small pocket of wind-drifted snow around a steep convexity. The slide ran around 500 feet downhill and did not provoke a larger or wider-breaking slide.