Northern San Juan
AvalancheChris Bilbrey · Mar 25, 2019 · Northern San Juan
Weather
Springtime in the San Juan's with warm temperatures, bluebird skies, and light winds at higher elevations. Snow surfaces remained cool at upper elevations with moist conditions below treeline and in gullies.
Snowpack
Snowpack continues to make its slow transition from a winter to a spring pack. Moist snow near the surface at lower elevations while the snowpack remains dry above 11,000 feet. Stiff upper snowpack making triggering avalanches in deep weak layers more difficult and most likely needing a larger trigger like a cornice fall. East to south through west-facing slopes at all elevations have a newly formed melt-freeze crust with shady aspects continuing to hold soft snow. We didn't observe any concerning weak layers in the top meter of the snowpack in a WNW snowpit above treeline, but known variability in snow depth above treeline still kept us searching for deeper areas. Only sign of instability we observed were loose dry sluffs running long distances from morning sun and warm-up. Otherwise, we felt comfortable traveling in steeper terrain while minimizing exposure of the group. Numerous small loose wet slides below treeline but all were small and generally harmless.
Avalanche
Watched several loose dry sluffs run close to 1,500 feet on an east aspect between 10:00 - 10:25 am pouring over cliffs above creek bottom. None stepped down below recent storm snow, but did entrain a large amount of snow while moving downslope.