The next storm has begun to impact the area. A Winter Storm Warning has been issued by the National Weather Service. New snowfall and strong southwest winds will continue to add to the existing wind slab problem as well as further load deeper weaknesses in the snowpack, allowing for the possibility of large to very large avalanches to occur. Skier triggered avalanches will be likely and natural avalanches will be possible at all elevations this morning. The sensitivity and size of potential slab avalanches will increase as the day progresses raising the danger to High in the afternoon at the upper elevations where natural activity will become likely. Make conservative decisions with regards to backcountry travel plans today, watch for areas of wind loading and avoid any backcountry travel in the afternoon that exposes your group to potential natural or skier triggered activity from above.
Southwest winds and new snow over the last few days have formed soft slabs in steep avalanche terrrain. These slabs could fail on yesterday's snow surface or back to when the storm cycle started on Saturday. Slabs will increase in both size and sensitivity today with slabs depths this afternoon of up to four feet at the higher elevations and to a foot at the lower elevations.
Additional weight is being added to a snowpack with buried weak layers. At the mid and high elevations, slabs could fail on faceted snow and/or crusts buried by the last storm on February 2nd and have depths of two to five feet. At low elevations, the snowpack is shallow and wrought with weak faceted snow that may fail near the ground with depths to two feet.
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.
