Galena Summit & Eastern Mtns

The avalanche danger will increase dramatically overnight, reaching EXTREME tomorrow. Very large avalanches capable of destroying a wood frame house are almost certain. Avoid all avalanche terrain. Avalanches may impact roadways, trails, and structures in the valley bottom. Avalanches may be triggered remotely—from gentler terrain above, below, and to the sides of steep slopes.

A full Backcountry Avalanche Forecast will be available by 7:00 AM Friday.

A powerful snowstorm will arrive tonight, overloading a weak snowpack by morning. Snowfall will begin in earnest around 6 PM as a moisture-laden atmospheric river takes aim at central Idaho. The storm will be in full swing by morning, with precipitation rates of 1-2" of snow per hour and moderate to strong S and SE wind. Large to very large avalanches are likely overnight. Intense snowfall will continue throughout the day and a widespread natural avalanche cycle is almost certain.

Temperatures will climb near freezing at low elevation aiding in the release of numerous top-heavy storm slabs and increasing the odds of dangerous roof avalanches. This avalanche cycle will not be confined to the backcountry. This large of a storm would likely prompt HIGH danger on its own, but to make matters worse, it's all landing on an incredibly weak snowpack. The combination of the two will produce very large or historic avalanches that are expected to impact roadways, trails, and structures in the valley bottom. 

Please stay out of the way. This means avoiding all avalanche terrain, including flat terrain like walking trails or roads that traverse beneath steep slopes. Avalanches may be triggered from large distances—from gentler terrain above, below, and to the sides of steep slopes.