Good Morning, this is Janet Kellam with the Forest Service Sun Valley Avalanche Center with the Backcountry Avalanche Advisory and Weather Forecast for Sunday February 22nd 1998 at 7a.m. Today this forecast is sponsored by: The North Face the guys that make the kind of storm gear that you wish you had yesterday. Today the avalanche danger is estimated to be: CONSIDERABLE throughout the Wood River and Sawtooth Valleys Considerable Hazard, means natural avalanches are possible, human triggered avalanches are probable, and unstable slabs are probable on steep terrain, (or in this case aprx 30 degrees and steeper until conditions settle down) Synopsis: We received just about an inch of water yesterday and winds blew ferociously, gusting nearly 60mph out of the South then later gusting in the 40’s out of the West. The temperatures were cool at the beginning of the storm and warmed up throughout the day. Then the temps did drop back down at the end of the storm to make some nice turning conditions, but deceptive avalanche stability. The result was that we had heavier, denser snow that fell on top of some lighter snow. Particularly in the Central and South Valley and below 10,000ft. Not only that, but the beginning of the storm fell on slick, frozen melt freeze crusts on the sunnier slopes, or light dry recrystallized powder and surface hoar on the cooler aspects. Yesterday in the Galena Summit area I found cornices and wind rolls to be very sensitive to ski cuts. The snow readily cracked and released as slabs below me on small test slopes. The wind transport was phenomenal, 8-10 inch deep tracks were buried within a half hour in any exposed areas. Knee deep drifts formed in about 2 hours. So , today you will find the new snow to be sensitive and/or wind slabbed in many locations. Even areas that do not appear to have any wind loading have denser snow that lies on top of lighter weaker snow and it will be possible to produce some avalanching of this new snow on steeper slopes on all aspects. If it becomes clear and warm today, sunny slopes could see some surface slides. The valley temperatures are forecast to rise into the mid forties and this will tend to make that new snow want to creep downhill, just like the snow that is falling off of your roof. I would be particularly careful at mid to lower elevations in the Central and South Valley where this may trigger deeper releases. It is also very necessary to be concerned about deeper layers in the snowpack. On Northwest, North and North east aspects I found that not only was the newer snow sensitive, but our buried surface hoar layer was starting to feel the load. This layer that was approximately 12 to 20 inches deep, now lies 20 to 30 or more inches beneath the surface and has quite a load on it. Last week we continued to see or hear of skier and snowmobiler triggered avalanches, some on fairly low angle, ususpecting slopes. What was happening was that this weak surface hoar layer was barely able to support the overlying snowpack without a failure and the shock of a human turning or riding on the slope created just enough stress or load to cause the snow on the slope to fail. Our new 10" of snow (and in wind loaded areas we received much greater amounts.) will cause more slopes to fail naturally or bring them just that much closer to failing with a slight trigger. Where I had previously been getting #4 and 5 Rutschblock failures, I was getting a clean, crisp easy #4. And this was in the Galena Summit area where the snow has been the most stable. Thunder clap sounding collapses were reported from the Lake Creek ridgeline yesterday afternoon and a fairly large soft slab broke loose on this layer and tried to move on a low angle slope. As the sun comes up today and we have clear skies I would expect to see some slab releases from yesterday. We also received reports of very weak, loaded snow in the Indian Creek area. I would expect to see some natural or human triggered activity in the southern half of the valley from Trail Creek southward, especially on the weaker North or Northwest aspects. This is where in the past few weeks we have been seeing some activity with avalanches running on the ground layer of weak snow. So today it is essential to practice safe routefinding and use all your avalanche knowledge in making decisions. Paying close attention to slope angle will be imperative not only what you are on, but what may lie above you, in your search for that perfect powder run. Tip for the day: Do your buddies a favor and try some practice beacon searches today. There have been some great live recoveries with beacons this season, and some equally tragic losses due to the surviving members not being practiced with their beacons. Best Snow Conditions: Reports came in yesterday of excellent conditions on all aspects except for the wind scoured slopes. You want to stay fairly low angle until you can confirm the stability of a slope. Conditions are excellent for snowshoeing and snowmobiling, perhaps a bit deep in places. Observers: Let us know of any avalanche activity that you may see today. If you can tell, what layer is it running on and how deep is it. We would love any Rutschblock results in order to see just how the buried weak layers are handling the new load. Everyone, please call 788-1200 ext 8028 with snow or weather obs. if you do get out today. Titus Ridge,at 10,000’ reports: Onite low: 9 max temp: 21 winds:12SW 24hr av:22SW Max gust:57S @2pm Wind Notes: During the storm we experienced high winds from the South and intense precip rates. With the frontal passage early yesterday evening the winds shifted to come from the West and continued to gust into the 40’s snow:new 10”-12” storm#15 and storm total:10” total stake:68” Forecast for 10,000ft:Winds SW x15-25 mph Max Temp: 16 Min Temp:5 Snow: scattered showers forecast bringing 1-2” today and tonight. Bald Mt, at 9,000' reports: similar conditions compared to Titus and Galena Summit but warmer temperatures. Valley Floor, at 5800' reports: Onite low: 10 max temp: 34 snow:storm total past 36 hours 11” density:6.5% total stake:42” Weather: The NWS is calling for an upper level low pressure to keep some cold moist air over Central Idaho. This could combine with the projected warm temperatures on the valley floor to produce scattered snow showers in the mountains. Although I see incredibly clear skies overhead at 6AM. Another storm is forecast for Monday afternoon that could bring either big winds or fairly big snows from the Great Basin. An important announcement: Winter mountain goats are typically found on sunny, wind swept ridges and rock outcroppings between 8,000’ and 11,000’. They are vulnerable and especially susceptible to disturbance in the winter. Please stay at least 1/2 mile away from them; take your binoculars so you can enjoy them from a distance and, if you see any goats, please report your sighting to the SNRA at 727-5000. This forecast is available daily on the internet at 1) www.avalanche.org 2) www.csac.org To receive daily e-mail of this forecast, you can subscribe at the bottom of our csac.org forecast page. This forecast only applies to the backcountry and it is based on a limited number of observations in specific locations.