Flathead Range & Glacier NP

Continue to enjoy generally stable avalanche conditions. Your most significant hazard will likely be managing the surface crust that is hard and supportable in some locations and thin and breakable in others. Maintain proper travel protocols by riding one at a time while having your partner in sight.

With no significant change in the weather today, expect to find more of the same conditions as days prior. If you haven't gotten out, check recent observations to catch up on what people find. To summarize, a crust blankets the landscape up to at least 7400 feet on all aspects. The crust is thickest and most supportable between 5000 and 6500 feet. Due to the crust's structural integrity, it is unlikely to trigger an avalanche failing on layers below the crust and is especially true where it is supportable to a person's weight.

On Sunday, we observed two very large (D3) avalanches in the Flathead Range (observation). We suspect they failed sometime between Tuesday night and Wednesday morning during a warm, wet, and windy storm. These avalanches most likely failed on the early December crust/facet layer near the ground. The avalanches occurred in steep, rocky terrain on east and northeast aspects between 7100 and 7500 feet. 

So far, we've observed this early December crust/facet layer in all three forecast zones. It can be found on all aspects above 6500 feet and observed as far down as 6000 feet. It appears to be more developed and weaker on shaded slopes where more snow existed before it was buried in early December. Just across the border in Canada, this layer is proving to be much more reactive. We were surprised to see no avalanche activity after the atmospheric river, which ended on January 8th. This storm dumped roughly 3.5 inches of SWE (snow water equivalent) at Flattop in Glacier National Park. It appears that the extra inch of water that fell three days later and warming temperatures is what tipped the scales.

Moving forward, we will continue to pay close attention to this layer. Please let us know if you see any large crowns while out in the mountains. Thankfully, it is unlikely for a human to collapse this weak layer because it is buried deep in the snowpack. If you decide to step into steep terrain, hedge your bets on open, planar slopes and steer around steep, rocky, complex-looking terrain where snowpack depths are more variable in thickness and the layer is closer to the surface.