This is Chris Lundy of the Sawtooth National Forest Avalanche Center with your Backcountry Avalanche Advisory and Weather Forecast for Sunday, February 3, 2008 at 7:30 am. The Twin Falls District Bureau of Land Management & the Friends of the Sawtooth Avalanche Center bring you this advisory. Special Announcement: A very special Thank you! goes out to everyone who made this years Best of Banff Fundraiser a huge success. This of course includes everyone who attended the films and bought raffle tickets and especially Michael Boge and the Friends of the Avalanche Center who organized the event. We also owe a debt of gratitude to Backwoods, the Elephants Perch, Sun Valley Heli Ski, Ski Tek and all the local businesses who generously donated prizes for the raffle. Congratulations to Molly Goodyear who won the day of Heli Skiing for two! Bottom Line: In the South and Central Valley, the avalanche danger is estimated to be CONSIDERABLE. Weak faceted snow exists about 18-24 inches deep on most slopes. The poorest stability is on mid to lower elevation slopes where the snowpack remains shallow and very weak, or on any slope with new or old deposits of wind drifted snow. In the North Valley and Sawtooth Mountains, the avalanche danger is estimated to be CONSIDERABLE in windloaded areas as well as on southerly facing slopes. On shady aspects sheltered from the wind, the avalanche danger is estimated to be MODERATE. Facet layers can be found buried around 2 feet deep in this region as well, but they are not as pronounced as in our more southern mountains. The important exception is on southerly facing slopes where a crust/facet layer buried about 2 feet deep continues to show signs of instability. Strong southerly winds and new snow overnight have undoubtedly created fresh wind slabs along upper elevation, northerly facing ridgelines. Primary Avalanche Concern: The common thread throughout our region are layers of faceted snow beneath the storm accumulations from this past week. These layers formed in mid-January and can be found about 18-24 inches deep. These facet layers have shown the greatest instability in the South and Central Valley, especially at mid to low elevations. In Lake Creek yesterday, I dug a snowpit on a shallow, westerly facing slope and found extremely weak, sugary facets beneath the snow that has fallen over the past week. Scores from three different stability tests all produced very easy and clean shears failing on the facets (see photos below and video, http://www.youtube.com/watch?v=t2cDrPj-an8 ). These test results made it easy to understand the recent avalanche cycle around Ketchum and Hailey on lower elevations slopes, and from my pit I observed a natural avalanche across Lake Creek in Taylor Canyon that ran on Friday. I also did other pits on more northerly facing slopes where the snowpack was a bit deeper. Stability tests in these areas showed slightly better stability but still produced very clean and energetic shears. Given these conditions, I would feel very uncomfortable on any slope with an angle steeper than the low 30s. In our Northern Mountains the facet layers are not quite as pronounced, except on southerly facing slopes where a layer of facets on a crust continues to raise the hair on many avalanche professionals necks. I saw it a week ago right as it was starting to get buried, and since then many easy and very clean shears have been reported on this layer. On Friday, a skier remotely triggered a south aspect near Butterfield, and poor stability on south aspects was reported in Konrad Creek yesterday. A skier-triggered slide occurred yesterday on a mid elevation, southerly aspect in the Boulder Foothills above Phantom Hill (see photo below). Many shady aspects in the North Valley are showing better stability so the easy solution is to stick to these slopes. Secondary Avalanche Concern: Southerly winds increased overnight and peaked around midnight. With a fluffy snow surface and a several inches of new snow, there is plenty of snow available for transport. Watch for freshly formed wind drifts along northerly facing, upper elevation ridgelines. In addition to wind slabs that formed overnight, strong winds over the past week have formed wind drifts on a variety of aspects. Some of these have the potential to break down into deeper facet layers. Current Conditions: Since yesterday, weve picked up about 4-6 inches of very low density new snow, with even more reported in Hailey. South to southeast winds began increasing yesterday evening and blew strongly overnight, especially on Titus Ridge where they averaged 25-35 mph with gusts into the 40s. Temperatures this morning are in the single digits at all elevations. Todays statement of the obvious is that excellent powder conditions can be found on almost all slopes. Density inversions have had a few days to settle out so sliding and riding conditions may actually be improving. Mountain Weather Forecast: A low pressure system will continue to move through our region today, bringing a chance for 2-4 inches of more snow before it peters out this afternoon. Temperatures are expected to be slightly warmer today, with upper elevation highs in the mid teens to low 20s. The valley is forecasted to reach the upper 20s. Ridgeline winds should decrease this morning and blow 10-20 mph through the day, initially from the south but shifting to the west then northwest later today. Another round of strong wind, this time from the north, is expected overnight.