Above 7,500 feet, skiers and riders still have the potential of triggering small to large persistent slab avalanches in steep, avalanche prone terrain. There is a significant amount of spatial variability associated with these persistent slabs. Many slopes are stable, some are not, and it is difficult to distinguish between the two. The likelihood of triggering these slabs will slowly increase as additional weight is added to the underlying weak layers. Your simplest tool for avoiding these dangerous avalanches is to make conservative terrain choices. Backcountry travelers might also be able to trigger shallow pockets of newly developed wind slab in steep, wind loaded terrain. Mostly stable snow exists below 7,500 feet.
Large grained facets exist near the base of the snow pack. In some areas above 7,500 feet, buried layers of surface hoar also remain a concern. On steep, avalanche prone slopes, backcountry travelers could trigger persistent slab avalanches failing on these weak layers. These slabs could range in depth from one to three feet.
( Discussion is generated from the previous day's afternoon forecast. )The National Weather Service has issued a Winter Weather Advisory effective until noon on Sunday. The heaviest snowfall is expected overnight with the Tetons being favored where 6 to 10 inches of new snow could accumulate by Sunday morning. Snowfall intensity will decrease as the day progresses. Overnight lows in the mountains will be in the upper teens before rising into the upper 20s in the afternoon. Southwesterly ridgetop winds will range from 20 to 30 miles per hour.The general avalanche hazard is expected to be Moderate above 7,500 feet on Sunday. While the hazard rating may not change, the likelihood for avalanche activity will be on the rise. Considerable hazard might develop in the Tetons if the snowfall forecast is exceeded. Overnight, new wind slabs with depths ranging from 6 to 18 inches will form in leeward terrain, and backcountry travelers could trigger these slabs on steep, wind loaded slopes. The chance for skiers and riders to trigger persistent slab avalanches, one to four feet deep, will slowly rise as weight is added to the underlying weak layers of faceted snow. These deeper slabs could also step down from the release of a wind slab. Monitor the weather, and be willing to alter your travel plans if conditions warrant. Unless an unexpected rain on snow event occurs below 7,500 feet, avalanche activity will remain unlikely.
