Conditions remain dangerous. During the past two days snowmobilers have triggered very large slab avalanches and smaller slab avalanches have been triggered by skiers and a snowboarder. A snowmobiler was caught and carried on Monday and a skier near Teton Pass triggerd a slide that broke trees and moved deadfall yesterday. The persistent weak layer that has been responsible for widespread avalanche activity is well preserved and will continue to produce large avalanches that can kill or seriously injure backcountry users. Sunshine and warming temperatures will be increasing the likelihood for these dangerous slides to release. Conservative terrain choices remain essential for safe travel in avalanche terrain.
Dense slabs up to six feet in depth lie upon a persistent weak layer of faceted snow. These slabs could be triggered on a variety of aspects by the weight of a single person or release after they have been crossed by multiple skiers or riders. At the lower elevations smaller pockets of dense slab up to two feet in depth could be human triggered on steep avalanche prone slopes.
Wind slabs up to 30 inches in depth could be human triggered in steep wind loaded avalanche starting zones and on convex roll overs. Once triggered these slabs could step down and create a very large deep persistent slab avalanche.
After mostly clear conditions tonight, clouds are to increase on Thursday as a cold front approaches from the northwest. This system should bring snow to the area Thursday night. Mountain temperatures during the day are to rise from the upper teens to upper twenties and southwest winds are to increase throughout the day, with averages of twenty to twenty five miles per hour expected in the late afternoon. The general avalanche hazard will remain Considerable above 7500 feet. Dangerous slabs, that could be small to very large, remain very sensitive and could by triggered by a single person. Slab depths and hardness depend greatly upon elevation. At higher elevations depths could be as great as six feet and will release as hard slabs. As elevation decreases to near 7500 feet, depths are more likely to be 18 inches to two feet. Below 7500 feet, avalanche activity is likely to occur only on steep north facing slopes and pose greatest threats in terrain traps.
