Northern San Juan
AvalancheColin Mitchell · Dec 5, 2022 · Southern San Juan
Weather
Warm and partly sunny. Light southwest winds at pass level.
Snowpack
We are finally developing a snowpack on Molas and Coal Bank passes. Southerly-facing paths like Henry Brown, East Lime, and the Engineers were bare ground before last week's storms. These areas now have a snowpack which consists of 6-12" of moist rounds, with a thin crust in the sunniest areas. Warm temperatures and sunshine today will lead to more crust formation. Northerly and easterly-facing slopes have a more concerning structure. In West Lime, the HS is around 12-18", the bottom half is Fist-hard 2-4mm depth hoar and large-grained facets, and the upper half is a 1-finger hard slab formed by our recent snows. The coverage, the extent of the weak layer, and snow depth vary across the slope, casting some doubt on the possibility of enough propagation potential to produce a large avalanche here. Lots of surface roughness still visible, and there were plenty of bare patches before last week's storms. Nevertheless, the structure is concerning, and mitigation would be indicated with a large load. Access is difficult to the Champion group, but this area harbors the basal weak layer, and a similar snowpack to West Lime.
Avalanche
2 D1 Soft Slabs ran over the weekend on northeast-facing rollers just north of Molas Pass. These slides were typical of what we saw over the weekend. This morning, a D1.5 Wet Loose released from Gobbler's Knob. All of these slopes are frequent runners.