The primary avalanche problem of concern today is wind slab avalanches. Periods of strong N/NE winds throughout the week have transported considerable amounts of recent storm snow at the upper elevations of Douglas Island. Human triggered avalanches are possible, primarily on S/SW aspects and lee features above 2500' and near ridgetops. Signs of wind slab instability can include shooting cracks, collapsing, or hollow feeling snow.
Wind slabs can vary greatly in size, distribution, and sensitivity to triggers over small areas. Localized wind effects in alpine terrain require a heightened level of caution when traveling in avalanche terrain during wind slab conditions. Fresh and actively loading wind slabs are especially hazardous. Signs of wind slab can include shooting cracks, collapsing, or hollow feeling snow.
After another unusually cold snow event early this week dropped highly variable snow amounts across the Juneau/Douglas area we are back to a persistent high-pressure regime and the outflow winds that accompany it. Periods of strong N/NE winds have sporadically occured at the uppermost elevations of Douglas over the last several days and have created wind slabs of highly variable depth and hardness. Many of these wind slabs are overlying a weak layer of faceting snow grains that are developing at the interface of the early December melt freeze surface and the more recent storm snow. Cold dry conditions are forecasted to continue into next week and N/NE winds are predicted to increase through the weekend which will likely keep wind slabs building at higher elevations for the near future. Finally, we would like to say thank you for all of the public observations that have been posted recently. They give us valuable information and we are excited to see so much community participation in keeping backcountry users well informed.
