Good morning, this is Sue Burak from the Inyo National Forest Eastern Sierra Avalanche Center with an avalanche advisory for Saturday, February 7, 2009. MOUNTAIN WEATHER Steady snowfall will diminish to showers this morning as the low leaves the eastern Sierra. Unsettled weather continues through the rest of today with snow showers over the mountains. Winds have been from the south during the storm but have shifted to the northeast as the low moves east and upslope, wrap around snowfall continues throughout the day. June Mountain could pick up an additional 6 to 10 inches from upslope snowfall today. Skies will be partly cloudy Saturday night with northeast winds gusting up to 40 mph. Winds increase on Sunday for a cool and windy day in the mountains. Reno NWS could post another Winter Weather Advisory for the Sunday night into Monday storm with slightly less snowfall amounts expected for the Mammoth and June areas. Highs today will be in the mid to upper 20s at the 8,000 to 10,000 ft elevation. Lows for the next few days will be in the low to upper teens. The weather pattern will be unsettled for the week with small weak storms moving through our area every couple of days. Snow accumulations from each storm will be light and limited to elevations above 8,500 ft. SNOWPACK AND AVALANCHE DISCUSSION The Mammoth Mountain and June Mountain backcountry areas received 16-22 inches of new snow from the Friday and Saturday storms. The southern Sierra picked up 8-10 inches of new snow above 9,500 ft, with a few storm totals in the 18" range. A few inches more snowfall could fall today especially in the Mammoth and June Mountain areas. Winds were light yesterday with Mt Warren recording a period of many hours on Friday with calm winds-it is more likely the sensor is down. Yesterdays new snow was about a foot deep and fist hard. Our stability tests on 30-32 degree slopes were failing easily and cleanly in the stuffblock and extended column tests. Efforts to detect buried surface hoar yesterday in the pits were thwarted by moderate snowfall obscuring the view under microscope. Some failures occurred on the interface between the new snow and the old snow surface and some failures occurred within the new snow. In open areas between trees in low angle terrain, we heard some whumpfing and saw some short shooting cracks. There are several avalanche concerns today. New snow sluffs could knock a person off their feet. While winds were mostly light, there was strong enough wind gusts that could move snow onto north facing slopes and form wind slabs. A 15 mph wind will move plenty of snow to make a wind slab. Morning winds light and from the the northeast, but the 24 to 48 hour wind direction was from the south and southwest so for today, the windloading is a concern on north facing terrain. Finally, with pockety and isolated areas of surface hoar buried under one to two feet of new snow, it will be wise to avoid north facing slopes steeper than 35 degrees,especially those with rocky and/or shallow features where a slide could more easily be triggered. The best way to deal with the uncertainty of where one might find a surface hoar layer is to remain conservative, and avoid problem areas and likely trigger points. These would include mid to upper elevation shady slopes steeper than 35 degrees today, especially if they have rocky features or shallow spots. Avoid climbing steep open slopes in the trees, especially convex shaped slopes. BOTTOM LINE The avalanche danger rating is only a starting point. YOU CONTROL YOUR OWN RISK by choosing where and when you travel. The avalanche danger rating is CONSIDERABLE in the Mammoth and June Mountain backcountry today. Variable conditions and uncertainty require conservative decision making. Careful route selection and good travel habits are required. Continually analyze conditions when traveling in avalanche terrain- which is where we usually go. Natural avalanches are possible. Human triggered avalanches probable. The avalanche danger rating is CONSIDERABLE for the Sonora Pass to Bishop Creek areas today. Please note that the avalanche danger rating in this advisory expires in 24 hours. This advisory is our 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.