Late yesterday afternoon, the Bonneville County Sheriff’s Department received a call that a snowmobiler was missing in an avalanche accident northeast of the Sheep Creek area in the Snake River Range. Rescuers made it to the accident scene yesterday evening and will return this morning to resume recovery efforts. Also this week, a snowboarder died in an avalanche on Mt. Taylor on April 1. These are tragic events, and our deepest condolences go out to the friends and families of these avalanche victims. The snow that fell on Tuesday has settled and is bonding to old snow surfaces. However, some instability remains at the higher elevations on very steep, avalanche-prone slopes. These instabilities may increase in sensitivity on solar slopes that receive warming from the sunshine. Humans who venture into those areas could trigger large slab avalanches. Avalanches are unlikely below an elevation of 9,000 feet, except for the possibility of small, wet, loose slides during the warmest periods of the day. Please be conservative with your actions and stay up to date with Health Department emergency alerts at, http://www.tetonwyo.org/163/Health-Dept
At the upper elevations, drifted snow lies over a variety of surfaces including crusts. These wind slabs could be up to 2 feet in depth and could release under the weight of a single person. Due to clear skies and warming temperatures, the likelihood of triggering these slab avalanches may increase as the day warms and solar radiation melts snow surfaces.
Expect cloud cover to increase this evening followed by the development of light snow showers. Light, scattered snow showers will be possible through the afternoon on Sunday. In the afternoon, precipitation will transition to rain in the valleys. A few breaks in cloud cover will also be possible. Overnight temperatures in the mountains will be near 20 before rising into the mid-30s during the day. Southerly to southwesterly ridgetop winds will range from 10 to 20 miles per hour.The general avalanche hazard is expected to be Moderate above 9,000 feet on Sunday. Up there, skiers and riders could trigger wind slabs one to two feet deep in steep, avalanche prone terrain. These slabs could be come more susceptible to failure in the afternoon as temperatures climb above freezing, especially if extended periods of sunshine occur. Any extended periods of sunshine could also result in small wet loose slides on steep, sunlit slopes. If snow surfaces start to become wet, transition to shaded terrain. In both of this week’s fatalities, the victims were wearing transceivers, but tragically neither of their beacons were turned on. This a stark reminder to do full beacon checks before leaving the trailhead. For every person, verify their batteries are good, and their transceivers are both sending and receiving properly.
