This is a revised forecast for the Southwest Trails area.Riders and skiers have the chance to trigger new soft slab avalanches and older slabs in steep terrain. In areas where significant new snow is falling sensitive wind slabs could be triggered. These storm slabs could be largest in the southern and eastern areas. Older, harder slabs could also be triggered that vary in depth from one to four feet, with the deeper slabs possible at the higher elevations. Thursday a group of snowmobilers had a close call when they triggered a sizable slide in the Snake River Range and yesterday the second skier on a slope triggered a sizable slide at low elevations in Grand Teton National Park.
New snow and wind have combined to form surface slabs in avalanche terrain. These soft slabs could have one foot depths this morning and could increase in size and sensitivity as additional snow falls today.
Persistent slabs lie upon weak snow surfaces formed during a mostly dry period in January. These slabs could have depths ranging from one foot at lower elevations to possibly four feet in wind loaded areas at higher elevations. Predicting where the weaknesses could still be triggered is problematic at this time as many slopes will hold before a similar slope fails. Evaluate snow and terrain carefully and identify features of concern.
( Discussion is generated from the previous day's afternoon forecast. )A well developed storm is tracking northeast from the Great Basin. This storm is to bring significant snowfall to the Salt and Wyoming ranges overnight through Saturday. Over a foot of snow is possible in these areas. The Teton and Togwotee Pass areas could see five to seven inches during this time. The avalanche hazard is expected to remain Moderate in the Teton and Togwotee Pass areas and will likely increase to Considerable in the Southwest Trails/Greys River area where significant loading and stronger winds are expected. Existing persistent slabs to four foot depths could be triggered in steep terrain. These slabs will become more sensitive as additional snowfall loads them during the day and the possibility to trigger new soft surface slabs will also develop in areas where significant snowfall and wind loading occur.
