The National Weather Service has issued a winter weather advisory today. New snow will load slopes, and increase the potential for backcountry travelers to trigger persistent slab avalanches. Above 7,500 feet, skiers and riders could trigger slab avalanches up to two feet in depth. These slabs lie upon a persistent weak layer and could be triggered by the first person to cross a slope or after a slope has been crossed multiple times. Assess the snowpack carefully and practice safe travel techniques. The hazard is low below an elevation of 7,500 feet, where slab avalanches are unlikely.
As the snowpack remains thin, buried persistent weak layers continue to be a concern. This season, prolonged periods of dry weather formed a variety of weak layers that may become reactive as snow loads slopes and could result in avalanches. Assess conditions and the snowpack with today's new snowfall.
( Discussion is generated from the previous day's afternoon forecast. )The high-pressure ridge will move eastward ahead of a cold front that is expected to impact the forecast area by Saturday morning. Snow should develop first over the Tetons and Togwotee Pass and then quickly spread south to the Southwest Trails. Accumulation is expected to be 4 to 10 inches across the region by Sunday morning. Temperatures will start in the teens with a slight valley inversion and then warm into the twenties. Ridgetop winds are expected to be southwesterly at 10 to 20 miles per hour with stronger gusts. On steep slopes, dangerous avalanche conditions remain a concern, where the weight of a single person could trigger a one to three foot deep avalanche. Above 7,500 feet, the general avalanche hazard is expected to be Considerable in the Southwest Trails and Teton areas and Moderate on Togwotee Pass. Below 7,500 feet, where avalanches are unlikely, the general avalanche hazard is Low. As tomorrow’s new snow loads slopes, the increased weight could add to the potential of triggering persistent slabs. These killer slabs could be triggered by the first person or after a slope has been crossed many times. Careful assessment of terrain is important for safe travel in the mountains.
