Northern San Juan
AvalancheColin Mitchell · Mar 30, 2021 · Southern San Juan
Weather
Warm and windy. Temperatures reached the mid-thirties at highway stations for a couple of hours this afternoon, with the exception of Monument, which topped out at 29 degrees. SW winds increased through the morning and stayed brisk all day. Some isolated blowing snow observed in the alpine.
Snowpack
At the Coal Bank study plot, recent snows have settled out to about 30 cm of 4f-1f rounds sitting on the old, dusty crust formed back around March 9th. The snow surface was wet, and foot pen was around 50 cm. On nearby steeper, sunnier slopes, like the Engineer paths, recent snows had settled down to only a few inches and were starting to shed off of old crust layers. Henry Brown, East Lime and the Waterfall area are quickly melting out. Henry Brown is thin and patchy. The snowpack, where it exists, is composed of around 12" of isothermal snow and crusts with a couple inches of moist-wet rounds on top. This path no longer poses a threat to the highway, and that is unlikely to change. The East Lime area is right behind. HS is in the 12-18" range in East Lime and thin and patchy elsewhere. We have received 33" of snow on Coal Bank over the past two weeks, but the the master stake is only up 2", illustrating how much settlement, as well as some melting, that has taken place. The other stakes are similar, Molas is at 52" (-1" since the 17th), and West Lime is at 52" (-6" since the 17th). SWE at nearby Snotel sites is still increasing and tracking with our observations. This shows that melting hasn't really taken off yet, but I suspect it will begin in earnest by the end of the week.
Avalanche
No new activity observed today. Lots of rollerballs and a few sluffs from yesterday.