Southern San Juan
SnowpackChris Bilbrey · Feb 22, 2024 · Southern San Juan
Weather
Cool, crisp morning with clear skies and light northwest wind. Temperatures warmed nicely by midday.
Snowpack
Overall snow depths in the area south of Molas Pass remain thin for the last-half of February. The stiff-over-soft, aka "trap-door feel" structure where we traveled is likely a function of how weak early-season facets got when snow depths were atypically shallow. Now buried under a meter thick slab, weaker snow grains are starting to gain strength but still capable of failure. Digging on a north-facing slope near treeline, we found a stout slab around a meter thick sitting above the 4F hard January facets. This interface continues to produce sudden planar failure in Compression Tests (CTs) with moderate to hard force, but we could not initiate a failure in ECTs. Of note, CTs did not fail in a shallower, slightly harder (1F-) layer of near-surface facets that developed in early-February. Recent winds laid a hard wind-board on the surface around an inch-thick. Sunny slopes harbor a similar thickness crust. Both hard surface layers have F hard near-surface facets below. As of today, these hard surface layers appear thin enough to bridge but not defend the weight of a major snow load above. This will be something to monitor when wintry weather returns. Shady slopes harbor 15 to 20 cm worth of F hard facets sitting above a 1F hard layer below.