Strong winds and new snow will form new wind slabs on leeward aspects that will gain depth and volume as the day progresses. These slabs are likely to be easily triggered by skiers and riders and will be large enough to bury or kill a person. In areas were the snow structure is poor, today's winds and snow could initiate the failure of very large, deep slab avalanches. These destructive avalanches could run long distances would be un-survivable. The general avalanche hazard is expected to increase to high at the upper elevations and may increase to high later in the day at the mid elevations. Travel in avalanche terrain is not recommended during periods of high avalanche hazard. Avoid known avalanche paths and their runout zones.
Strong westerly to southwesterly winds will be forming fresh wind slabs. These surface slabs could be 1 to 4 feet deep and become very sensitive to human triggers. These wind slab avalanches could step down and trigger a much larger deep persistent slab avalanche.
Persistent deep slab avalanches are a serious concern. These dangerous avalanches could be triggered by backcountry travelers or occur naturally. They could also step down from the release of a wind slab avalanche. These destructive avalanches are likely to be 4 and 8 feet deep above an elevation of 7,500 feet and 2 to 4 feet deep below that elevation.
Snowfall is expected to continue overnight with an additional 4 to 8 inches across the forecast area by morning. The heavier snowfall amounts should continue to favor the Grey’s River and Teton forecast areas. Southwesterly to westerly ridgetop winds will be 15 to 30 mph and then lessen by tomorrow afternoon. A weak northwest flow will bring mostly cloudy skies and light snowfall through tomorrow, and then dry weather is expected as a ridge builds over the region. Temperatures will be cold starting in the single digits and then warming into the low to mid-teens. Snowfall and wind continue to load the snowpack and form wind slabs on leeward slopes. Humans are likely to trigger slab avalanches up to 8 feet deep. Winds slabs at the upper elevations are expected to be sensitive and up to 3 feet deep. Triggering a smaller wind slab could step down and initiate a larger avalanche with un-survivable consequences. Depending on the intensity and duration of the storm overnight will determine the likelihood of triggering an avalanche tomorrow. At the highest elevations, the avalanche hazard is expected to be High and Considerable in areas with less snowfall and wind effect. Regardless, conditions are dangerous and travel in avalanche terrain is not recommended.
