Tetons

In the Tetons, persistent weak layers can be found on most aspects and at all elevations. Over time, these problem layers have become much less reactive to human triggers, however, events involving them still remain a slight possibility today. At the mid and upper elevations slab avalanches of one to three feet are possible. Deeper slabs have become unlikely, especially to the weight of a single person. At the lower elevations, smaller slab avalanches one to two feet deep are possible only on steep isolated terrain features. Even small avalanches can carry severe consequences in unforgiving terrain such as unsupported slopes, couloirs and terrain traps. Less sensitive conditions still warrant a thorough assessment of the snowpack in order to identify and avoid areas of concern.

The first of a series of systems will move across the area tonight and tomorrow. This first system is weak and accumulations are to be light with just a few inches expected by 5pm Wednesday. Temperatures are to remain cool, with temperatures at 9000 feet starting in the single digits and rising into the upper teens. Southwest winds are to have averages between ten and twenty miles per hour. The general avalanche will be Moderate in all forecast areas. Be mindful that Moderate covers a wide range of conditions between a stable snowpack in which avalanches are not expected (Low hazard) to a snowpack that is being impacted by weather to such an extent that natural activity is possible and human triggered slides are likely (Considerable hazard). The Teton area is on the low range of Moderate, however, slabs can still be human triggered, particularly in and around cliff areas, as happened today. It is still recommended to avoid high consequence terrain where small slides could cause serious injury or death. In the Togwotee Pass and even more so in the Southwest Trails areas, weak layer distribution is more widespread and more unstable areas remain susceptible to human triggers, particularly to larger loads such as snow machines. Above 7500 feet slab depths could reach as much as 5 feet in the Southwest Trails area and four feet in the Teton and Togwotee Pass areas. Below 7500 feet avalanches are currently unlikely, however the snowpack on lower slopes is weak and could become active with new loading.