Southeast Mountains

Large and destructive avalanches are being recorded daily. These avalanches are failing during periods of increased winds and during more intense bands of snowfall. The possibility of continued natural avalanche activity will hold us at CONSIDERABLE or DANGEROUS avalanche conditions for upper elevations. Continuing to limit your exposure, or simply avoid overhead hazards, such as traveling below large avalanche paths, is a good strategy. At lower elevations in the SE Mountains, your primary avalanche problem remains managing persistent slabs. The weaker than average snowpack and generally shallower total snowpack height for this area will keep the sensitivity to human triggering elevated. A collapsing snowpack or shooting cracks is a red flag indicator that you could trigger this avalanche problem. While no signs of instability may simply mean that you just need to find the right trigger point. Remember, any triggered or natural avalanche today could break head high, propagate wider than expected, and become deadly as they run long distances. 

The Ruby Range did its orographic thing yesterday, with total snow accumulations for the last 36 to 40 hours in the 10 to 20-inch range. While total snow accumulations in the SE Mountains during that same time period were closer to the 5 to 8" range. What snow did accumulate was cold and very low density. West to northwest winds started increasing yesterday afternoon and peeked around sunset. We observed at least 1 large natural avalanche run on Whetstone Mountain. We'd further expect to see more natural avalanches with this morning's good visibility, that also ran during those increased winds. With so many recent and destructive natural avalanches this is not the time to step out into more aggressive avalanche terrain. If visibility remains good today, you need to be careful of the potential to let yourself fall into the human factor trap that clear sky and fresh snow can bring. Many avalanche crowns around the area have been head high, to double overhead, let that sink in. These are the monster avalanches that you are dealing with.

The below treeline avalanche danger was dropped to MODERATE in the NW Mountains and remains CONSIDERABLE in the SE Mountains. This is due to the average slab depth over the buried persistent weak layers for each of those forecast areas. Where slabs are thick and deep, it will be harder for the weight of a human to affect the burred weak layers and trigger an avalanche. In that case, a human may not initiate a collapse until they find the right trigger point or a thin spot on the slope. In the SE Mountains, those slabs are on average thinner and the same avalanche problem is expected to be more reactive to human triggering across more of the landscape. Where you find a total snowpack height near or below 120cm's the persistent slab avalanche problem is expected to be more reactive to human triggering. Where you find a total snowpack height near and above 170cm's the same avalanche problem is expected to be more stubborn to human triggering. Of course, there is a gray area between those numbers, and you could also find below-average snowpack depths in the NW Mountains or above-average snowpack depths in the SE Mountains. Another factor that will lead to abnormal snowpack depths is past avalanche activity.