Southern San Juan
SnowpackChris Bilbrey · Apr 6, 2020 · Southern San Juan
Weather
Warm and sunny day with a few high passing clouds. Light to moderate southwest wind made a valiant attempt at keeping snow surfaces cool but to no avail up to about 11,000 feet. As we approached treeline, snow surfaces slowly cooled but still softened up.
Snowpack
Wet snow concerns continue to "march" up in elevation during our current warm-up. Another natural wet slab avalanche on a southeast aspect and large cracks opening up on an east aspect highlight our ongoing wet problems. Old, weak facets that loom below the upper slab are now moist to wet on lower elevation slopes facing east through south to west. The introduction of water into those weak layers reduces the strength of bonds between grains making them more susceptible to fail from either the slabs own weight or the extra push from a rider. This weakness was observed in numerous snowpits and as we climbed higher in elevation toward the timber line. Although failures in ECTs were more stubborn near treeline than the clean, planar fractures we observed below treeline, the same concerning structure exists. Additional above freezing nights and warm daytime temperatures will most likely keep this threat alive and reactive till our next cool down with below freezing temperatures.