Yesterday, a snowboarder triggered a 12 inch pocket of soft slab on a north facing aspect at 9,250 feet in the southern Tetons. At the higher elevations, skiers and riders could trigger similar slides when venturing into very steep, avalanche-prone terrain that has been recently wind loaded. Cloud cover should mitigate the effect of the sun. However, if extended periods of sunshine occur, the likelihood of triggering these slides will increase on sunlit aspects, along with the chance for shallow wet loose sluffs. Monitor the sun’s impact on snow surfaces, and avoid steep avalanche terrain that has signs of recent wind loading. The springtime snowpack at the lower elevations is mostly stable and avalanches are unlikely.
Strong southwesterly to westerly ridgetop winds late in the week stiffened recently developed wind slabs and added to their depth on leeward aspects. Above 8,500 feet, skiers and riders could trigger these wind slabs to depths of two feet in very steep, wind-loaded avalanche terrain. Winds became less pronounced with a drop in elevation, and the likelihood of triggering these slabs decreases accordingly.
Southwesterly flow could bring some light snowfall to the region overnight and into Sunday. A low pressure system off the coast of the Pacific Northwest will move into the region late in the day on Sunday, and moderate to heavy snowfall will be possible. Overnight lows in the mountains will be in the upper teens before rising into the low 20s during the day. Southwesterly ridgetop winds will increase to 25 to 40 miles per hour as a jet streak moves overhead.The general avalanche hazard is expected to be MODERATE on Sunday. A chance persists for backcountry travelers to trigger recently developed wind slabs up to two feet deep in very steep, wind-loaded terrain above 9,000 feet. Late in the day, strong winds and snowfall will begin to form shallow pockets of new wind slab on leeward slopes. These slabs will form upon firm sliding surfaces in terrain that is exposed to the wind or to the sun.
