Tetons

Fourteen to 18 inches of new snow with an estimated moisture content of 0.5 inches has fallen at the mid and upper elevations in the past 28 hours. This snowfall has been accompanied by strong southwest winds and created very dangerous avalanche conditions. Travel in avalanche terrain is not recommended at the upper elevations. At the mid elevations dangerous avalanche conditions exist on steep northerly aspects and in the tracks of upper elevation avalanche paths. Excellent terrain evaluation skills are essential for safe travel in avalanche terrain. Yesterday large dangerous avalanches were triggered by cornice drops and remotely by skiers. With more snow and wind in the forecast natural avalanche activity is likely and human triggered avalanches are very likely. Slabs depths are expected to be up to three feet deep.

An upper trough is forecasted to move over the region from the west bringing moderate snowfall overnight. Accumulations of 5 to 10 inches of new snow are expected by midday Monday. Temperatures will cool off to the mid teens overnight and warm little during the day. Winds will increase to 35 M.P.H. along the ridges, with stronger gusts. With easily triggered and natural activity occurring before current totals and another several inches of new snow with strong winds expected, the avalanche danger is expected to remain HIGH at upper elevations in the Tetons. The light-density, new snow will be worked into easily triggered slabs by forecasted winds. Most hard slab events have occurred on north and east aspects at upper elevations where faceted layers have been developing for some time. The Southwest Trails/Greys River areas, Continental Divide/Togwotee Pass areas and Mid elevations in the Tetons are expected to have a Considerable Hazard Monday.