Dangerous avalanche conditions exist at the upper elevations. Since Friday afternoon, the Tetons have received around two feet of new snow containing up to two inches of snow water equivalent. Strong southwesterly to westerly winds accompanied this snowfall, and wind slabs have developed in leeward terrain. Yesterday, a 20 inch deep, skier triggered slide was reported on a northwest facing aspect at an elevation of 9,500 feet at the Grand Targhee Resort. Similar slides are likely today in steep, wind loaded terrain above 9,000 feet. At the mid elevations, where winds had less of an impact, smaller slides will be possible. The low elevation snowpack is mostly stable, and avalanches are unlikely. Don’t let the abundance of new snow impair you judgement; careful snowpack and terrain evaluation will be essential for safe travel in avalanche terrain.
In steep, avalanche prone terrain, backcountry travelers could easily trigger recently developed wind slabs with depths ranging from one to four feet. These slides are most likely to occur in terrain that held October snow. In these areas, anchors are being covered, and old snow surfaces provide potential failure zones.
Periods of light to moderate snowfall will continue overnight before the jet stream moves north and a drying trend begins on Monday. Overnight lows in the mountains will be in the low 20s before rising to near freezing during the day. Southwesterly to westerly ridgetop winds will range from 15 to 25 miles per hour.The general avalanche hazard is expected to be Considerable at the higher elevations in the Tetons on Monday. In steep, wind loaded terrain above 9,000 feet, skiers and riders could trigger slab avalanches with depths ranging from one to four feet. In the Togwotee Pass and Southwest Trails forecast zones, where storm totals are less, the general avalanche hazard in the mountains is expected to be Moderate. There, similar slab avalanches up to three feet deep could be triggered on steep, avalanche prone slopes. In all the forecast zones, the likelihood of triggering a slide will be highest in terrain that held snow from October. Take this into account when evaluating the snowpack and terrain.As the Grand Targhee Resort prepares to open on Friday, the mountain will be closed to uphill travel beginning on Monday.
