Banner Summit

Generally safe avalanche conditions exist. Thin wind drifts in exposed, upper elevation terrain may continue to be sensitive to your weight. Be on the lookout for loose snow avalanches in steep terrain at all elevations. Weak snow exists at the base of the snowpack on upper elevation, north-facing slopes.

Daily Avalanche Forecasts have begun! Look for an updated forecast each morning by 7:30 AM. Subscribe here to get the forecast emailed to your inbox.

The snowpack in our forecast area is generally stable, but there are a few isolated hazards to be aware of. These fall into two broad categories: hazards related to the recent snowfall and weather, and hazards related to the weak snowpack that has developed this fall.

NEW SNOWThe storm on Sunday brought 2-3" of snow to this zone, enough to slightly improve the skiing conditions but not enough to significantly affect stability. Chris was out on a recreational ski tour near Banner Summit yesterday and found some small, isolated wind drifts up to 1 foot thick in exposed terrain. Click here to read through the observation he submitted. Another inch or two of snow today may help build another round of these drifts. Wind speeds will pick up through the day and the freshest drifts are likely to be the most sensitive to your weight. Even though these slabs will be small, if you encounter one in steep terrain it could push you into places you don't want to go. If you trigger one it may also be able to entrain some of the weak snow it is sitting on, as described below.

OLD SNOWThe weeks of dry weather, cool temperatures, and strong temperature inversions have left their mark on the snowpack. Our once strong and stable snowpack has weakened significantly. In the past two days, I've had conversations with both Scott and Chris discussing how this is some of the weakest snow any of us can remember seeing. I may be a young(ish) man, but these two have some serious experience under their belts; when they speak I pay attention. In many places, the snow is so weak that it is struggling to stay attached to the slopes it is resting on. On Saturday, a skier near Galena Summit was able to trigger a small, loose snow avalanche involving this cohesionless snow. My partner and I were able to trigger similar slides on Sunday, even at lower elevations on treed slopes. Watch this video I took in the Sawtooths on Saturday to get a sense of just how weak this snow has become. 

In addition to this weak snow in the upper half of the snowpack, we also have a monster lurking in the basement. In upper elevation terrain that faces away from the sun, remnant snow from October is buried at the base of the snowpack. These videos from the White Clouds and from Frenchman's Creek near the Salmon Headwaters do a good job of illustrating the problem. We've been on the hunt for this snow over the past few weeks and have found it in many locations. Without a stiff slab of snow on top of it, triggering an avalanche on this layer is unlikely, but the resulting slide would be unsurvivable. This low probability but high consequence hazard has kept me out of the terrain where it can be found.

LOW danger and no danger are different things. Snow-covered mountains are an unforgiving environment and the consequences of encountering even very isolated hazards can be high. Think about the dangers I described above when you are making your travel decisions today. Some of the hazards out there are a  bit unusual and you may not be used to dealing with them.