Southern San Juan
SnowpackChris Bilbrey Matt Huber · Feb 10, 2022 · Southern San Juan
Weather
Clear, sunny day to start gave way to thin, high clouds overhead by 2:30 pm. Temperatures reached the upper 20s Fahrenheit around 12,000 feet, and light westerly wind.
Snowpack
Our last field visit in the La Plata Mountains was exactly one-week ago. Then, it felt and looked like mid-winter. Now, it felt and looked more like early-spring. Northerly winds over the last 3 days have pressed, stiffened and scoured loose surface snow on open, exposed northerly-facing slopes above treeline. We encountered a thin and breakable wind skin above 4F- facets on larger, open slopes. Wind-sheltered areas and gullies were less wind-battered, and slopes with the slightest easterly tilt. The line of wind-demarcation varied from slope to slope, but generally consistent with the top terminus of treeline. We found the deepest volume (8 to 12 inches) of recent snowfall plus weak, faceted snow (F to 4F-) below on northerly and east-facing slopes near treeline, but sluffs were stubborn to initiate and traveled no farther than 100 feet down slope. Last week's snowfall has almost faceted throughout except for due north slopes, but those grains are quickly jumping on-board the facet train. Only isolated pockets of firm, wind-drifted snow on easterly aspects near ridge tops produced cracking below our feet. Snow cover and depth are depleting quickly on southerly-facing slopes, especially below treeline, and a firm crust await you below moist, faceted grains on the surface at upper elevations - kick hard to sink a ski edge. Overall, the snowpack across aspects remains supportive to ski and snowmobile travel. However, almost a month and a half into a dry, cool to warm weather regime is promoting weakening in snowpack structure from bottom elevations upward exacerbated in shallow, northerly-facing terrain.