Southern San Juan

A Special Avalanche Advisory is in effect from Friday evening through Sunday for the San Juan Mountains. A winter storm will dramatically change conditions, making it easy for backcountry travelers to trigger dangerous avalanches this weekend.

Expect rapidly changing conditions as new snow and wind form cohesive slabs over weak snow on many slopes. You are likely to trigger avalanches where you find more than a foot of new snow on slopes steeper than about 35 degrees. The most dangerous slopes will be those where winds have drifted snow into deeper, stiffer slabs on north-, northeast-, and east-facing slopes at upper elevations. Travel in backcountry avalanche terrain will require cautious route finding to stay safe.