This is Matt Lutz of the Sawtooth National Forest Avalanche Center with your Backcountry Avalanche Advisory and Weather Forecast for Thursday, January 3, 2008 at 7:30 am. The Sun Valley Telemark Series & Smiley Creek Lodge & the Friends of the Sawtooth Avalanche Center bring you this advisory. Bottom Line: Today the avalanche danger is estimated to be MODERATE. This means human triggered avalanches are possible. Overall most slopes in our forecast area are currently stable, but localized areas of instability do exist. Areas with potential instability include high alpine terrain, recently wind loaded slopes and ridgelines, steep rocky terrain and areas with thin snow cover overlying weak sugary snow. The National Weather Service has issued a Winter Storm Warning that will take affect late tonight through Saturday. This storm is unlikely to change the avalanche danger today, but as the storm starts to impact our area the avalanche danger will likely increase rapidly. Primary Avalanche Concern: The South and Central Valley currently have a very thin and weak snow pack. Most locations have such weak snow that there is no cohesive slab to cause trouble, with the exception being isolated wind loaded pockets along steep ridgelines. In the North Valley, Salmon River Headwaters, and Sawtooth Mountains the snow pack is generally stronger and deeper than in the southern terrain. The overall average snow depth in these areas is between 4 to 6 feet. The North Valley has the lower end of these totals with the Northern Sawtooth having the most. Uniform slopes with consistent snow cover offer the most stability. Areas with potential instabilities and greater danger include steep rocky terrain, high alpine terrain, recently wind loaded slopes and areas with highly variable snow cover. The common denominator for these areas is weak sugary snow near the bottom of the snowpack. To avoid areas with potential problems look for uniform terrain that has a consistent and generally deeper snowpack. Yesterday in the headwaters of Baker Creek I observed the remains of numerous surface slabs that probably naturally avalanched during last Sundays windy storm. These slabs appeared to be between 12 to 16 inches deep and were primarily on southerly aspects. Stability tests also showed that this shear layer is still present within the snowpack. Additionally I received a report that a snowmobiler triggered a small slab in the Salmon River Headwaters yesterday. I suspect that there may be a common thread involved. Additional Discussion, Throughout our forecast area the surface snow is quite weak and soft. The type of snow grains that make up this soft snow are called near surface facets. The near surface facets make for nice skiing and riding conditions and as long as they are on the surface of the snow pack they pose no real danger. However once near surface facets are buried they typically bond poorly to new snow. Current Conditions: Sheltered slopes at higher elevations and areas with greater snow cover offer nice soft snow riding conditions. Ketchum is currently under partly cloudy skies with a temperature of 6 degrees. Thanks to the inversion ridgeline temperatures are in the mid 20s. Ridgeline winds are light out of the south southwest. Mountain Weather Forecast: Today expect partly cloudy skies becoming mostly cloudy by afternoon. Ridgeline daytime high temperatures will be in the mid 20s. Winds should remain light out of the southwest with occasional moderate gusts. The big story is the incoming Pacific storm. Tomorrow we should see snow showers and potentially rain in the valley bottoms. Friday night through Saturday is expected to see the greatest snow fall intensity. This storm is expected to be warm and windy with mountain snow totals dare I say measured in feet!