Northern San Juan
AvalancheColin Mitchell · Mar 10, 2020 · Northern San Juan
Weather
Broken skies with periods of light snow and sun. Winds were calm at highway level.
Snowpack
I started in the Brooklyns and worked my way south. The snowpack in the Brooklyns is starting to turn to a more spring-like regime. The snowpack averaged 100 cm on the lower apron below J-H. Free water has penetrated about 30 cms and a prominent ice mass existed here. Below this, the snowpack was P-hard, moist rounding facets with no signs of water penetrating yet. The upper 30 cms consisted mainly of several crust/facet layers. I got easy to moderate CT results in these upper layers, and was able to get an ECTP26 right at the ground. Overall, this is a pretty solid snowpack that would need a significant load to produce a slab avalanche, and it would likely break only down into the upper 30 cms of the snowpack. The Jenny Parkers are still holding a more winter-like snowpack despite the low elevation. Hs was around 120 on average, with a couple of crust/facet layers in the upper 30 cms. The rest of the snowpack was much less consolidated than at the Brooklyns. The bottom meter or so consisted of moist, large-grained rounding facets that were unsuportable to boots with areas of 'trap door' on skis. Foot pen was basically to the ground. I got moderate CT results on some of the upper layers, but did not get propagation with an ECT. The structure here is a little more concerning, but the steep, rocky start zone appeared to have too much roughness to be much of a concern, and the rest of the path is too low angle to avalanche. South of Molas Pass, the south-facing paths like East Lime, Henry Brown, and the Engineers are melting out. West Lime has a surface crust, but is likely still cold snow. The stake read 44" which corresponds with a snow depth of about 30", less as you get closer to the road. Some of the larger rocks are poking through now.
Avalanche
No new activity observed