Aspen
AvalancheColin Mitchell, Brandon Levy · May 7, 2020 · Northern San Juan
Weather
A warm morning with clear skies and light winds. Winds began to pick up around 11, first with gusts, then sustained moderate winds with gusts into the 30's by afternoon.
Snowpack
The snowpack on northerly aspects in this area is transitioning to spring. Overnight lows in the upper 20's to low 30's combined with clear skies to make for a good freeze last night. Northerly and westerly aspects near and above treeline were still frozen at 11:30 when we ended our tour. The upper snowpack was a very stout (I-) 25 cm thick melt-freeze crust riddled with ice crusts. The average height of snow was around 2 meters across the slope. We targeted a thin area on a mid-slope terrain feature for our profile. Here we found another 35 cm of K-hard rounds, rounding facets, and melt-forms underneath the crust. Below that, were softer layers of old facets that were transforming to melt forms. Water had penetrated all the way to the ground at our profile site. A compression test failed with moderate taps and a sudden collapse on the weak snow near the ground (CT11 SC). An ECT in the same location, did not produce results (ECTX). We probed for the basal weak layers in deeper areas on this same slope, but we could not find them. I suspect these layers are much less pronounced where the snowpack is more than about 1.5 meters deep. Also, water may have not reached the ground yet in these deeper areas.
Avalanche
No new activity noted in the backcountry.