Numerous avalanche events and several close calls have occurred during the last three days. Recent events have released naturally, been remotely triggered and have been directly triggered by skiers and snowmobilers. A buried layer of surface hoar one to three feet below the snow surface and a deeply buried layer of weak faceted snow that formed in early December continue to be problem layers. At the mid and upper elevations dense wind slab avalanches could be triggered by skiers and riders. Deep persistent slabs could also triggered by backcountry users. Careful terrain and snowpack analysis is still warranted. Most avalanche fatalities occur during periods of moderate or considerable hazard. Avalanches are unlikely below an elevation of 7,500 feet except in isolated areas.
At the mid and upper elevations wind slabs one to three in depth could be triggered by skiers or riders on steep avalanche prone slopes. These slabs have been formed by southwest to west winds.
Dangerous deep slab avalanches continue to be a hazard at the mid and upper elevations. These large slab avalanches could be triggered by the weight of a single person who hits a shallow trigger point but are more likely to be released by larger triggers like a snowmobile. These slabs could propagate long distances, have depths to five feet and are likely to carry severe consequences to anyone involved.
A strong and moist westerly flow off of the Pacific will bring periods of snow and blowing snow to the mountains. Snowfall wise this flow will favor the western and northern portions of our forecast region. The higher elevations in those areas are forecast to receive 2 to 5 inches of new snow overnight and several additional inches of new snow during the day. Lesser amounts will fall in the Salt River, Wyoming and Wind River Ranges and at the lower elevations. Cooler air will move into the region. Temperatures will be in the teens in the mountains and in the 20s at the lower elevations. Winds will be westerly at 30 to 45 with gusts to 70 overnight and decrease to 20 with gusts to 30 miles per hour by tomorrow evening.At the mid and upper elevations (7,500 to 10,500 feet) backcountry users could trigger wind slab avalanches 1 to 3 feet in depth and large deep persistent slab avalanches up to four feet in depth. The general avalanche hazard is expected to be MODERATE at those elevations and LOW below an elevation of 7,500 feet.
