An avalanche warning has been issued for the area. Very dangerous avalanche conditions exist. Natural and easily triggered slides are likely today as a winter storm continues to load avalanche terrain. Sensitive large slabs were formed by recent snowfall of approximately 18" of new snow and strong southwest winds. Even larger slides are possible at high elevations where the snowpack is underlain by old persistent weak snow layers. Yesterday many natural and triggered slides were reported. Several of these slides impacted roadways including one that knocked a vehicle off the road and onto its side on Twin Slides near the top of Teton Pass just before dark. Avalanche activity is certain today and travel in avalanche terrain is not recommended.
Wind slabs formed by strong southwest winds could be human triggered in steep wind loaded avalanche starting zones. These slabs could have depths to three feet at higher elevations and one foot at lower elevations. They will increase in size and sensitivity as the day progresses.
Deep slabs lie upon a hard October rain crust and a persistent weak layer. These very dangerous slides could be triggered by the weight of a person with depths to four feet or could release naturally as they are loaded by new snow today. If involved with one of these large slides, survival is unlikely.
( Discussion is generated from the previous day's afternoon forecast. )A winter storm warning continues through 5pm Friday. Snow, heavy at times will continue through Friday. Temperatures are to remain on the warm side until cold air begins to move into the area in the late afternoon or evening. The cold temperatures are expected to result in a period of lighter snow as the storm moves east. Strong southwest winds with averages over twenty five miles per hour are to continue to blow on summits before becoming westerly and then northwesterly as the storm exists. The general avalanche hazard will be HIGH on Friday. Travel in avalanche terrain is not recommended. Large and dangerous avalanches could release naturally or from the presence of a single person. These events could involve wind slabs formed by this storm with depths to four feet by the afternoon on all aspects. Larger slides running on the deeply buried persistent weak layer near the base of the snowpack are also possible. These extremely dangerous slabs could have depth to six or more feet.
