Persistent weak layers are a concern. At the higher elevations (above 8,000 feet) skiers and riders could trigger persistent slab avalanches on steep avalanche prone slopes. Managing this hazard requires patience, expert terrain evaluation skills and conservative terrain choices. In these conditions existing tracks on a slope should not be taken to be an indication of stability.
Large slab avalanches 1 to 3 feet in depth can be triggered by the weight of a single person or after a slope has been crossed multiple times . Avalanches are unlikely below an elevation of 8,000 feet except on isolated terrain features.
( Discussion is generated from the previous day's afternoon forecast. )Conditions will be dry on New Year’s Day. Strong temperature inversions will redevelop. Skies will be mostly sunny. In the mountains temperatures will warm into the 20’s from morning lows near 10 degrees. In the coldest valley locations morning temperatures will be below zero. Light winds at 5 to 10 miles per hour will back from the north to the southwest.Most avalanche fatalities are caused by persistent slab avalanches. Managing this hazard requires patience, excellent terrain evaluation skills and conservative terrain choices. Dangerous slab avalanches 2 to 4 feet in depth can be triggered by humans on a variety of aspects above an elevation of 7,500 feet. In these conditions existing tracks on a slope are not to be taken as an indication of stability. The persistent slab avalanche problem is most acute in the Greys River area where large to very large avalanches are more easily triggered and the hazard remains considerable. Large slab avalanches can still be triggered by humans with severe consequences in the Teton area. Small to large human triggered slab avalanches could also be triggered by humans in the Togwotee Pas area where the hazard will be rated as moderate. Avalanches are unlikely except on isolated terrain features at the lower elevations in all three of our forecast zones. Be careful out there.
