Northern San Juan

Avalanche

Bill Nalli Amy Pertuz · Mar 6, 2020 · Northern San Juan

Weather

Clear sky in AM gave way to thin high clouds by mid day. Slight SW breeze helped keep temperatures lower near and above treeline.

Snowpack

Observed more evidence of a weakening snowpack on north though east aspects from the alpine to the low elevations. Not much of a slab above the weak faceting snow in the areas travelled but the structure is concerning as we approach a period of stormy weather and a potential new load. Southeast through southwest to west is also concerning. Many slopes with less than 120cm have a weak structure. Thursday's warm temperatures began to increase the liquid water in the snowpack causing a few loose wet and wet slabs late in the day. Slightly cooler temps on Friday helped to limit the wet activity but did not do enough to heal the poor structure just yet. It may feel like spring but many slopes still harbor a cold, weak structure and stability will be challenged with the next big load.

Avalanche

Loose-wet triggered a small wet slab in Arrastra Creek. March 5, 2020.