Southern San Juan
AvalancheChris Bilbrey · Apr 21, 2019 · Southern San Juan
Weather
We had an alpine start with light snow from 0530 to 0700. We observed a bathtub ring of noticeably warmer air temperatures between 9,800 to 10,000 feet this morning. Evidence of a hard freeze last night existed with frozen and supportable snow surfaces at all elevation bands. Skies cleared around 0800 with light to moderate southwest wind near and above treeline. Around 1030, clouds began to form and skies remained broken for the remainder of our tour. Cloud cover and wind kept air temperatures cool near treeline and above.
Snowpack
The snowpack below 9,500 feet is melting out quickly in the La Plata Mountains with some avalanche paths reaching valley bottom showing bare ground. We found a firm and supportable snow surface this morning after last night's freeze. Snow surface was weaker and more rotten in areas with heavier vegetation or near rocks below treeline. As we climbed higher in elevation, the snow surface got harder and boot penetration was limited to around 1 or 2 inches near and above treeline - this made for easy booting conditions along ridge lines. East to south through southwest-facing slopes near and above treeline warmed-up slowly from a mix of sun, wind, and clouds - we felt comfortable skiing steeper, sunny aspects this morning without incident. By mid-day, snow surfaces below treeline became wet and sticky but remained supportable overall. We didn't observe any new loose wet activity from today. Only signs of instability in this immediate area were small, loose wet slides from previous days warm temperatures. Despite temperatures not getting too warm and snow surfaces heating up slowly, we still stuck to our start early and end early approach. Lots of water running in all creeks with many waterfalls or water slides starting to open up. And...watch out for waking bears!
Avalanche
Small, loose wet avalanches from recent warm temperatures primarily on southwest-facing slopes near and above treeline. They were confined to the top few inches and didn't entrain a lot of snow while moving down-slope. Size of these avalanches is consistent with similar activity in the La Plata Mountains this spring.