Good morning, this is Sue Burak with the Inyo National Forest Eastern Sierra Avalanche Center with a backcountry advisory for Thursday, February 12, 2009. MOUNTAIN WEATHER After the cold, short lived storm last night, there will be a short break in the storm action today. Skies will be partly cloudy to mostly cloudy with brief patches of sun appearing east of Mammoth. Today, mid elevations from 8,000 to 9,600 ft will have north winds with gusts to 30 mph. The higher elevations will see north winds with higher wind gusts to 50 mph. As the next storm nears our area, winds will shift to the west in the late afternoon. The Friday storm is fast moving and will bring 6-8 inches of snow to the higher elevations. Strong winds up to 50 to 80 mph are forecasted to be from the south during the storm. The second wave of the Friday storm is expected to pass more to the north with a few inches of snow in our area. Temperatures will continue to be cold at the higher elevations with highs around 15 F and lows in the single digits. Elevations from 8,000 to 9,600 ft will continue to have highs in the low to mid 20s and low temperatures in the upper teens. The higher elevations will be cold with highs around 14-16F and lows from 0 to 8F. SNOWPACK AND AVALANCHE DISCUSSION Heads up everyone. The combination of several dry cold snowstorms and many hours of high winds has resulted in some very unstable snow conditions from the mid to high elevations in our area. One observer reported a road cut that avalanched yesterday and the fracture propagated 200 to 300 ft. Road cut sluffs and slab avalanches are a red flag warning that steep terrain is very unstable. June Mountain Ski Patrol reported yesterday that super reactive wind slabs failed easily during ski cuts, then propagated a long way, especially lower down on June Mountain. The aspect, slope angle and elevation of these slopes is similar to the popular north facing slopes west of the June Mountain. For every ski cut that triggers an avalanche, there can be far more snow hanging above every ski cut whether it occurs in a controlled ski area or in the backcountry. A good way to travel in the backcountry now is to test slopes with minor consequences and move deliberately in exposed terrain from one area of safety to the next area of safety. All backcountry skiers and riders should be on the lookout for smooth and rounded deposits of wind blown snow. These pillows have a chalky, dull appearance. Wind eroded snow has a sandblasted look. Right now, wind loaded slopes are found on northwest, north, northeast, east and southeast slopes- that pretty much covers all the choice skiable terrain in our area. If the snow feels slabby or punchy this means that denser and stiffer snow is sitting on top of softer, lower density snow. Also use your ears- sometimes a windloaded area sounds hollow. Whumphing and cracking are natures way of telling us the snow is unstable. Several of us heard whumphing on north and east slope aspects the last few days, from Bishop Creek to the June Lake area. Whumpfing confirms the patchy presence of buried weak layers- these weak layers could be buried surface hoar or weak snow sitting above the buried lens that formed near the end of January. You can find this on shady mid elevations in open areas in the trees and glades. The main avalanche issue today is easily triggered wind slabs formed by strong northwest and southwest winds. Windslabs are widespread- they can be found on most, if not all, steep slopes. Strong winds have come from the southwest, west, northwest, north and northeast since the weekend, and all of the slopes we like to recreate on are windloaded. BOTTOM LINE The avalanche danger rating today is CONSIDERABLE over slopes steeper than 30 degrees in high elevation terrain. This includes the Sherwin Ridge and the Negatives. Easy to trigger wind slabs will be found on terrain with a northerly, easterly and southeasterly aspects. A MODERATE danger exists in the north facing mid elevations at treeline and within the trees, where you could ski or ride across small open slopes where preserved and now buried weak snow is waiting for a trigger. The avalanche danger rating in this advisory expires in 24 hours. This advisory is my best interpretation of snow pack conditions and NWS forecasts issued today. Backcountry travelers should be aware that elevation and geographic distinctions are approximate and that a transition zone exists between upper and lower elevations. Avalanches do not happen by accident and most human involvement is a matter of choice not chance. Most avalanche accidents are caused by slab avalanches that are triggered by the victim of member of the victim's party. Even small slides can be dangerous. Always practice route finding skills and carry avalanche rescue gear. Remember that avalanche danger ratings are only general guidelines. Distinctions between geographic areas, elevations, slope aspects and slope angles should be made.