Southern San Juan
SnowpackChris Bilbrey · Dec 9, 2019 · Southern San Juan
Weather
A stunning blue-bird day with light northwest winds and cool temperatures.
Snowpack
Snow depths in this portion of the South San Juan zone are around 1 meter in many locations. Even southerly-facing slopes below treeline have enough coverage for easier travel - although many downed trees and stumps still protrude through the surface. We didn't observe any signs of unstable snow such as cracking or collapsing on north, northeast, east, southeast, and south-facing terrain where we traveled. The snowpack below treeline has gained strength quickly in this area and faceted snow at the ground is showing signs of rounding under a predominately 1F slab. We did not observe any storm slab formation with the recent storm arriving right-side up (4F to F). Facets at the ground are larger and more preserved at higher elevations and we found this persistent weak layer to be stubborn in long-column test near treeline. However, we did get an Extended Column Test to propagate on 30 taps in 4 to 5 mm depth hoar and facets. This confirms that if you were to find a shallow part of the slab or margin of a slab you could still trigger an avalanche that fails at the ground. We did not observe suface hoar in any of our snowpits but 5 mm surface hoar was noticed on the surface this morning in wind-sheltered areas.