Very dangerous conditions exist at all elevations. The Bridger-Teton National Forest Avalanche Center has issued an avalanche warning. Travel is not recommended in avalanche terrain. Up to a foot of new snow with up to 1.4 inches of moisture has fallen in the mountains since early yesterday morning. Natural avalanche activity is likely and may become widespread. Large avalanches could run long distances. Avalanches could affect roadways. Avalanches are possible on buttes, steep banks, road cuts and steep hillsides that don't normally slide. Stay off of and out from under steep slopes. Dangerous roof slides are likely.
At the mid and upper elevations strong southwest winds have formed dense, unstable wind slabs on lighter density snow. At the lower elevations these slabs are forming on top of a snowpack that has poor structure. Natural and human triggered releases are very likely. These destructive slabs could be up to three feet deep at the upper elevations and up to two feet deep at the lower elevations.
Large to very large slab avalanches could fail on persistent weak layers on a variety of aspects at all elevations. At the lower elevations these slides are very likely, could be wet and may dig down to the ground with total slab depths to four feet. At the higher elevations these destructive slabs could be up to six feet deep and may run long distances.
( Discussion is generated from the previous day's afternoon forecast. )Moderate to heavy snowfall will continue overnight and decrease during the morning hours. Heavy snowfall is forecast to resume on Thursday evening. Forecast snowfall totals for the next 24 hours are 10 to 20 inches in the mountains and 4 to 8 inches in the valleys. Southwest winds will also continue overnight at speeds of 30 with gusts to 50 miles per hour. Like the snowfall intensity those winds will decrease in the morning and increase again in the evening. Temperatures will be on the increase and will rise into the upper 20s in the mountains and well into the 30s in the valleys. The Bridger-Teton National Forest Avalanche Center has issued an avalanche warning effective from 5PM this evening until 5 PM tomorrow evening. This warning may be extended or discontinued as conditions warrant. The warning is in effect for all three of our forecast zones and includes the valleys in those areas. Strong winds, warming temperatures and heavy snowfall have created very dangerous conditions at all elevations. Natural avalanche activity occurred today and may become widespread, especially during the overnight. Large avalanches could impact roadways in the river canyons, on Teton Pass and beneath buttes and steep hillsides. Steep hillsides, steep banks and road cuts have and are likely to slide. Slides are possible on steep slopes that may not normally slide. The general avalanche hazard is high at all elevations. Travel in avalanche terrain is not recommended.
