Northern San Juan

You can trigger an avalanche on steep slopes where recent snow has settled or drifted into a cohesive slab above weaker snow. The most dangerous slopes are at upper elevations where southwesterly winds during the last storm drifted snow into deeper cohesive slabs on leeward slopes. Avoid rocky slopes above treeline that feature variable snow depths and may harbor buried slabs over weak snow deeper in the snowpack. You may not observe any obvious signs of instability, such as cracking or collapsing, before triggering a dangerous avalanche.

Warm temperatures and strong sunshine increase the chances of wet avalanches. Small pinwheels and rollerballs are an early warning sign to move towards shadier terrain. Avoid traveling on or under steep sunny slopes, especially later in the day when warming reaches its peak.

On February 20, a backcountry snowboarder was caught and killed in an avalanche on a terrain feature locally known as The Nose in the Middle Fork of Mineral Creek drainage, west of the town of Silverton. The avalanche occurred near treeline on a northeast-facing slope in the San Juan Mountains. You can read the preliminary accident report here.