Northern San Juan
AvalancheColin Mitchell · Mar 12, 2021 · Southern San Juan
Weather
Mostly clear skies with light to moderate southwest winds at pass level. Temperatures are rising quickly this morning.
Snowpack
The transition to spring is well under way in the southerly facing paths on this highway stretch. On Coal Bank pass, water has percolated most of the way through the snowpack even on aspect neutral terrain near the study plot. HS was 80 cm where I dug, and I found well-developed perc columns and ice masses down 60 cm. The upper few cm were already wet at 10 am, and the snowpack was moist throughout. Henry Brown was further along, and the snowpack in most of the path is 30-45 cm of large melt forms with a couple of old melt freeze crusts mixed in, including a stout one just below the surface that was supportable to boots. Plenty of bare patches starting to show through on the Engineers, East Lime area, and Henry Brown. West Lime is still holding a wintry snowpack. This week's snows formed the upper 25 cm of the snowpack, and was a 4-finger hard layer of dusty, wind-packed mixed forms. The snow in this layer was moist even on this shady slope. The snow surface itself was alternately wind-stripped and capped with a thin slab. Below this layer was a thick, solid mid-pack layer that was supportable to boots.
Avalanche
No new activity observed