Travel in avalanche terrain is not recommended today. Two days of significant loading have created very dangerous avalanche conditions. Natural activity is likely above 8,000 feet. Large avalanches in the upper elevations have the potential to travel into lower elevations. Wind slabs, deep persistent slabs and loose snow avalanches are all on the list for potential problems today. Be aware not only of the terrain you are travelling 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.
West and southwest winds combined with over 2 feet of new snow in the last three days have created unstable slabs in wind loaded terrain. These slabs will grow in size throughout the day and be 1 to 4 feet in depth. These slabs have the potential to release naturally and will be very sensitive to human triggers.
Weak layers of snow buried 3-7 feet below the surface hold the potential to produce very large avalanches. Avalanches triggered at this depth will have great destructive force and run potentially long distances. These avalanches could fail under the weight of a single person or the initiation of a wind slab. Avoidance of this problem is key today. Treat any terrain above 8,000 feet with suspicion and to hold the potential to produce avalanches on these layers.
High precipitation intensity rates will allow the buildup of enough loose snow in steep sheltered areas to be their own problem. Loose snow avalanches have the potential to carry people into terrain traps such as cliffs, gullies and trees. Pay attention to the terrain below you and consider the consequences of being carried and losing control of your snowmobile or skis in steep terrain today.
( 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.
