Travel in avalanche terrain is not recommended today. Two days of significant loading have created dangerous avalanche conditions. Natural activity is likely above 8,500 feet. Large avalanches in the upper elevations have the potential to travel into lower elevation runout zones. Be aware not only of the terrain you are traveling in but what sits above you. In the lower elevations expect newly formed slabs to build in steep isolated areas and be easy to trigger. Wind slabs and persistent slab avalanches are on the list for potential problems today.
West and southwest winds combined with over 12” of snow over the last 2 days have created unstable slabs in wind loaded terrain. These slabs will grow in size throughout the day and be up to 2 feet in depth. These slabs have the potential to release naturally and will be very sensitive to human triggers.
Weak layers of snow buried 1-4 feet below the surface hold the potential to produce large avalanches. Avalanches triggered at this depth will have great destructive force and run potentially long distances. Avoidance of this problem is key today. Treat any terrain above 8,500 feet with suspicion and to hold the potential to produce avalanches on these layers.
( Discussion is generated from the previous day's afternoon forecast. )A Winter Storm Warning issued by the NWS is current and will remain in effect until 11pm tomorrow night. Light to moderate snowfall will continue overnight. Expect snowfall to increase in intensity in the early morning hours. Snow will be heavy at times. In the Tetons expect 5” of new snow by morning and 20” by the end of the day. The Southwest Trails area can expect 6-8” by morning and 20” at days end. The Togwotee Pass/Continental Divide area will see 3-5” by morning and 12” by the evening. Wind speeds overnight will average in the teens and be out of the west. Winds will increase into the 25-30 mph range during the day tomorrow out of the west. Temperatures will rise into the mid twenties in the upper elevations and into the low thirties in the low elevations.The general trend for tomorrow will be an increase in avalanche danger in all forecast areas. Travel in avalanche terrain will not be recommended in many areas. Expect natural activity to be likely in the upper elevations. The danger will be high in the upper elevations of the Teton, Togwotee and Southwest Trails forecast areas. The danger will be in the considerable to high range in the mid elevations of the Tetons. Expect the danger to be considerable in the lower elevations of the Tetons and Southwest Trails and moderate on Togwotee. A variety of potential weak interfaces will allow the possibility of a wide range of avalanche sizes. The potential for large, destructive and un-survivable avalanches will be real tomorrow.
