Good morning, this is Sue Burak with the Inyo National Forest Eastern Sierra Avalanche Center with an avalanche advisory for Sunday, January 25, 2009. MOUNTAIN WEATHER The storm moved east Saturday afternoon and blue ski could be seen in the Crowley area and the White Mountains. Skies south of Mammoth are mostly clear this morning but the mountains are obscured with low clouds. The coldest lows in many days occurred this morning as a cold front pushed south through Nevada and into Mono County. Morning temperatures are 6-10 degrees colder than yesterday morning with only a 5 to 8 degree warm up expected today. Highs today will be in the teens above 9,000 ft. and reach the mid 20s in Mammoth and Aspendell. Temperatures will be in the teens and mid 20s with some warming beginning Tuesday. The weather forecast for Mono County calls for more snow but the snowfall amounts depend on where the trough and the accompanying inside slider also known as a Tonopah Low, end up tonight and tomorrow. This mornings NWS forecast has backed off considerably from previous thinking that a couple of feet of new snow could fall from Sunday afternoon to Monday. If the inside slider is in a favorable location and the winds stay steady and dont shear the low apart, Lee Vining and June Mountain could see more snowfall than the 6-8 inches forecasted by Reno NWS on Monday. The Sierra south of Mammoth could receive 2-6 inches above 8,000 ft tomorrow and Monday. Winter storm warnings have been posted in Nevada, east of Mono and Inyo Counties as the storm track will favor snowfall to the east of our area. Winds veered to the west at many high elevation sensors as the trough approached the area yesterday. For Sunday and Monday, winds will be from the southwest and west and ridgetop gusts will be in the 30-60 mph range. Winds will shift to the north by early Monday morning and temperatures will continue to be cold until Tuesday, when a high pressure ridge builds over the West. . SNOWPACK AND AVALANCHE DISCUSSION Storm totals from Thursday are starting to add up. The 24 hour snow totals from 6 AM Saturday to 6 AM Sunday are approaching 2.5 to 3 feet of new snow in the Mammoth Basin and Mammoth Mountain. June Mountain has close to 2 feet of new snow. South of Mammoth, Rock Creek Lodge received about 8-10 inches of new snow and the farther in the range one goes, storm totals decrease. South Lake picked up 5 and about 10 inches accumulated at the 10,000 ft elevation in Big Pine Creek and Crabtree Meadow- Crabtree is on the west side of the crest. More snow fell north with the Sonora Pass area reporting close to 100 inches of snow and 3.4 inches of water added to the snowpack. The snowpack at Tioga Pass and Ellery Lake doubled since Thursday. Control results and stability tests from yesterday show the new lower density snow bonded well to the old snow surface. There was no whumpfing, cracking or recent avalanches in the areas I traveled yesterday. The first inch or two of the old snowpack surface is moist but the grains still are faceted. The old snow remains faceted and as it gets more deeply buried, the instability is more stubborn, meaning a large avalanche is becoming harder to trigger but it still could provide a good spanking. South and southwest winds yesterday created areas of wind loaded slabs- this occurred in open areas in the trees at the 9,500 to 10,000 ft level. Avoid any area that looks freshly drifted, and watch for hard slabs that feel drum-like or hollow. With 6-12 inches of new snow forecasted for the time period Sunday evening through Monday morning, there will be instability within the new snow and yesterdays snowfall. Winds have been strong enough to move snow and create tricky winds near ridgetops and in exposed areas at the higher elevations. The avalanche danger rating is CONSIDERABLE today from the Mammoth basin north to Sonora Pass. The danger rating is applied to all east to north facing slopes above 9,000 feet. I recommend you carefully assess the snowpack before you commit to playing on any slope steeper than 30 degrees. Variable conditions and uncertainty require conservative decision making. Careful route selection and good travels habits are required. If you get out in the backcountry leave me a message at 924.5510 or send me an email with your observations, sburak@psln.com. Thank you! BOTTOM LINE The avalanche danger rating is CONSIDERABLE today from the Mammoth basin north to Sonora Pass. The danger rating is applied to all east to north facing slopes above 9,000 feet. I recommend you carefully assess the snowpack before you commit to playing on any slope steeper than 30 degrees. Variable conditions and uncertainty require conservative decision making. Careful route selection and good travels habits are required. 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.