Skiers and riders have the potential to trigger loose snow sloughs and wind slabs in steep avalanche terrain. The wind slabs are mostly likely to found above 8000 where, as elevation increases, they are more widely distributed, more sensitive and larger. Below 8000 feet, avalanches are unlikely, however, isolated pockets of wind slab can be found in very steep, loaded terrain. Evaluate terrain carefully noting areas of loading and features of concern. Remember also that in terrain with long run outs, small slabs or sloughs can quickly involve enough surface snow to knock travelers down the slope and potentially bury them in terrain traps. The slight possibility for a slab involving weak snow near the base of the snowpack also exists. Triggering these slabs is unlikely, and would require a large trigger to hit either a thin spot in a large filled in avalanche path or an area where the snowpack itself is both shallow and underlain by weak snow.
Slabs formed by strong winds and snowfall during the past week can be triggered in steep terrain above 8000 feet with depths to three feet. Watch for area of recent buildup that are masked by the new snowfall. At lower elevations in very steep terrain, isolated pockets could be triggered with depths to a foot.
Some possibility might remain for a persistent deep slab avalanche to be triggered if a thin spot in a large avalanche path is impacted. If one of these large to very large avalanches were to occur, they would more likely be stepping down from the release of a wind slab or triggered by a cornice drop and could have depths to six feet. Old weak snow is also well preserved in areas where the snowpack is shallow. In very steep shallow terrrain, slabs to two foot depths could be triggered and clean out snow to the ground.
( Discussion is generated from the previous day's afternoon forecast. )Light snow is expected to fall tonight, becoming heavier after midnight. Snow is to diminish by late morning. This storm is tracking from the north and will favor the Teton and Togwotee Pass areas where three to four inches is expected. Approximately half that amount is expected in the Southwest trails areas. Expect morning temperatures in the single digits with highs near twenty. West winds overnight with averages near twenty miles per hour are to veer to the northwest and decrease as the day progresses. The general avalanche hazard will be Moderate at higher elevations and Low at lower elevations. In the Tetons, wind slabs lie at all elevations but are more widespread, more sensitive and deeper above 9000 where pockets to three feet could be triggered. Isolated, shallow pockets could be triggered below that elevation. In the other forecast areas that break in elevation for more abundant and more sensitive slabs comes at 8000 feet in the Togwotee area and 7500 feet in the Southwest Trails areas. In higher terrain there, wind slabs to three feet could be triggered. In areas with a shallow snowpack slabs could be triggered with two foot depths in isolated areas. A very slight chance also remains at Togwotee for a big heavy load to trigger large to very large hard slabs to the ground in steep avalanche paths.
