Soldier & Wood River Valley Mtns

You're most likely to encounter enough snow for avalanche problems in the high mountains on the western side of this zone (the Soldier Mountains and the mountains above the South Fk of the Boise River). If you're headed for these areas, refer to the Sawtooth and W Smoky Mtns Forecast. The majority of this zone lacks enough snow for significant avalanche problems. Daily Avalanche Forecasts with danger ratings will begin when snow coverage increases. 

We've got a beautiful, sun-soaked powder day in store for us. Unfortunately, a weak layer near the base of the snowpack keeps our hackles raised. Early-season snowfall weakened significantly in November and was buried by storms in December. The main driver of avalanche activity thus far has been the presence and distribution of this weak snow. Its not all doom and gloom out there, but if you head into the backcountry be prepared to deal with a complex, variable snowpack. Read on. 

The Good: In November, warm weather and sunshine melted the snow off of all low elevation slopes and many middle elevation slopes that face the sun. When snowfall returned at the start of December the snow was falling on bare ground in these areas. Observations thus far indicate that this newer snow is bonding well to itself and to the ground. On these slopes, you'll have a much lower likelihood of triggering a large avalanche. The downside is that you'll also find a shallow snowpack with plenty of stumps and rocks and logs still exposed.

The Bad: On all upper elevation slopes and most middle elevation slopes that face away from the sun, you'll find our problematic early-season weak layer at the base of the snowpack. In the mountains on the eastern edge of our forecast area (Pioneers, Boulders, White Clouds), the slab on top of this weak snow is in the 1-1.5 foot thick range on sheltered slopes. In the mountains on the western edge of our area (Western Smokys, Sawtooths, Banner Summit area) this slab is 2-3 feet thick. Across our area, this layer is well within the realm of human-triggering. 

In many places, it will not be visually apparent whether the early-season weak snow exists or not. It is possible to walk from a slope without this weak snow to one with it and not be able to tell that you have. When you do, your chances of triggering a large avalanche increase dramatically. If you head out today, you'll find yourself enjoying a stunning winter day. You'll also find a complex snowpack with some very real avalanche problems. Before committing to avalanche terrain, take a deep breath of cold air and an honest account of your understanding of the snowpack. Be prepared to travel conservatively in areas with weak snow at the base of the snowpack, understanding that triggering avalanches large enough to bury you is uncomfortably likely. 

Watch Brooke's Weekend Update to get a sense for what's been happening in our snowpack.