Tetons

Generally stable avalanche conditions exist today. Look for shallow wind slabs formed from increased wind this morning on isolated terrain features. Continue safe travel practices in avalanche terrain even during times of decreased danger.

The Rundown

The Tetons have not received significant snowfall for nearly a week. Moderate-strong winds of varying direction worked over snow surfaces throughout the week. Warm daytime and cold nighttime temperatures over the last two days have stiffened previous wind drifted slabs making them hard and unreactive. Last night, wind speed increased after midnight above 30mph out of the west/southwest gusting to 50 mph. Forecasted wind speed tapers off during daylight hours. Look for any shallow wind slabs that formed from this short burst of wind. Wind drifted areas will likely be isolated to complex terrain such as confined features like couloirs or aprons below cliff bands. Be wary of wind loading off exposed ridglines.

Remember that low danger does not mean no danger. Evaluate the snow surfaces carefully, and if you encounter signs of instability such as cracking or reactive wind slabs, move to less wind affected terrain. Minimal snow is forecasted with 1-4" by the end of the day. 

The persistent slab was removed from the avalanche problems this week as these layers have trended to unreactive. Weak layers near the bottom of the snowpack that formed early this season are buried 3-6 feet deep by hard overlying slabs in most locations. Avalanche activity has been few and far between over the last couple weeks. The last persistent slab avalanche in the Tetons occurred naturally during a large wind event on terrain with distinct characteristics that was very steep, rocky, and heavily wind loaded (St Pattys Day Couloir). A large trigger, such as a cornice fall, or exceptionally bad luck finding a thin, shallow spot in wind affected terrain would be necessary to impact the weak layer and trigger a very large avalanche. We will continue to track the buried weak layers, especially if we receive a large loading event or strong storm.