This is Janet Kellam with the Sawtooth National Forest Avalanche Center with General Snow and Weather Information on Friday, November 23, 2007. This information will be updated as we get more snow and more people head into the backcountry. Snowpack: IMPORTANT UPDATE 11/23- FRIDAY Snow conditions for oversnow travel of all types are very limited and isolated to upper elevations. This morning we received a report of a large, triggered slide in the Upper Salmon River basin-This means The Headwaters, Vienna-Beaver Creek area. Several snowmobilers were at 9,200 to 9,500 feet, being cautious and not highmarking but were near or along a steeper slope. They released a large slide estimated at 300 to 400ft wide. This was a Northeast facing slope and broke out an estimated 3 feet deep. Only one person was in the avalanche and was able to ride out unharmed. They did not observe any other slide activity, but this could have been a deadly slide. Thank you for reporting this it will help to alert others. Avalanche Concerns exist for these upper elevation locations. We have a build up of denser surface snow due to our recent wet storm and wind. Beneath the surface slab on north facing slopes lies weak, sugary snow on top of an ice layer. It is possible to trigger a slide, especially where the wind has blown more snow onto the slopes. This instability will persist for awhile so be cautious if you do get out. The fact that only one person was exposed at a time and this group was prepared and cautious helped to prevent a serious accident. General Information Wednesday, November 21 We have yet to get out into the field, but weve received a few reports from folks venturing out in the Galena Summit area. Most shaded slopes above 9000 feet had snow on the ground prior to last weekends storm, and now have around 1.5 to 3 feet of total snow depth. Below about 9000 feet or on any slope that faces the sun, there is significantly less snow. Unfortunately this includes popular Galena Summit ski slopes such as the Cross and Avalanche Peak. Where a snowpack existed prior to last weekends precipitation, it consisted of several crusts formed by rain events in October. Some of these crusts may have facets above or below, and these are likely the primary stability concern at this time. Skiers on Titus Ridge last weekend reported collapsing and whoomphing of the snowpack, indicating that these lower layers may have been struggling to support the foot or so of new snow. The snowpack seems to have calmed down since then, with skiers in the same area Wednesday reporting only an isolated collapse. With such a shallow snowpack, avalanches are just one of the hazards you will face out there. While you may be occupied with dodging rocks and stumps, dont forget that if theres enough snow to ski or ride, theres enough snow to slide. Weather: Dry, cold weather is expected to prevail through Saturday. From Sunday through at least Wednesday, several minor disturbances are expected to move through our region bringing a chance of snow with each. Currently, none of these appear to be the money maker but at least its not high pressure.