At the mid and high elevations, careful snowpack and terrain analysis is essential today to avoid the risks associated with avalanches that could be triggered by the weight of a single skier or rider. These avalanches could be large to very large, involving weak snow layers that were buried in December or smaller involving just recent snow along high elevation ridge lines and peaks. Although these slabs have become less sensitive to triggering, they continue to pose a serious threat to human life and demand respect. Avalanches are unlikely below an elevation of 7,500 feet except in isolated areas. Yesterday a snowmobiler was caught and fully buried in an avalanche near Lookout Peak in the Wyoming Range. Initial reports say the person was uncovered in approximately ten minutes. His or her condition and other details are not known at this time.
At the mid and upper elevations dangerous persistent deep slabs up to five feet in depth could be human triggered on a variety of aspects. These slabs could still fail due to the weight of a snowmobile or a single person who encounters a shallow weak zone. These slabs could propagate and run long distances and are likely to carry severe consequences to anyone involved.
Dense wind slabs formed by strong west winds could be human triggered to depths of two feet. Once initiated, these slabs could pull out deeper layers, resulting in a large destructive deep slab avalanche.
Periods of light snow are forecast to continue through Friday. Accumulations will be on the light side. Temperatures in the mountain should stay in the twenties through the day before colder air moves in Friday evening. Strong west winds overnight are to lessen throughout the day and veer to the northwest in the afternoon. The general avalanche hazard will be Moderate above 7500 feet. It is paramount that backcountry travelers understand that it is rated Moderate because the sensitivity of these dangerous slabs has lessened, as evidenced by the lack of natural activity occurring the last few days. Moderate means that a load is needed to cause the failure and the potential still remains for a single person to trigger a large or even very large dangerous avalanche. Staying off of steep avalanche terrain and choosing lower angle terrain is still the smart choice this year. Avalanches below 7500 are unlikely tomorrow.
