Southern San Juan

Avalanche

Chris Bilbrey · Feb 23, 2023 · Southern San Juan

Weather

Steady snowfall throughout the morning. Winds were generally light below 10,000 feet becoming stronger as we traveled higher. Moderate to intense drifting along treed ridges and in wider openings.

Snowpack

We found 10 to 12 cm of new snow that fell overnight. Below that appears to be a fresh layer of dust. This did not influence the stability of the storm snow in multiple snowpits. Storm totals ranged from 50 to 70 cm of a right-side-up slab. Yesterday's strong wind did a good job of pressing the snow into place making it less arduous travel today compared to yesterday. Once we climbed above 10,000 feet, lots of evidence exist of atypical drifting below the treeline with cornices forming at the crest of micro-terrain features. Yet again, the denser layer of snow that fell at the start of the storm is yielding good bonding at the new/ old snow interface. However, we identified several stubborn to reactive storm layers in snowpits on a west-northwest and north aspect below the treeline producing mixed fracture planes. The upper interface was a thin layer of graupel and the deeper interface consistently broke at a density change about 5 to 10 cm above the new/ old snow interface. Both snowpits were dug in areas sheltered by the wind, and it may take finding a wind-thickened slab or traveling on slightly steeper slopes to provoke an avalanche. We did not observe test failures at the Valentine's Day interface that was consistently 1F- and rounding facets.

Avalanche

No new avalanche activity was observed. Skies remained obscured providing no views into bigger terrain.