17-18

<p>Snow in town Saturday morning was a generous reminder to dig out the snow tires, gather firewood, and prepare ski gear. Many folks took advantage of 1-2 feet of dense new snow in the mountains, and we heard about great skiing as well as signs of instability and avalanches.</p>

<p>If there is snow on the ground it is time to think about and prepare for avalanches. Here are some things to consider as we dust the cobwebs off our winter toolbox.</p>

<ul>
<li><u>Everyone</u> in your group should <u>always</u> carry a beacon, shovel, and probe. Put fresh batteries in your beacon, check your probe and shovel for damage, and know how to use them.</li>
<li>Travel one at a time in avalanche terrain, whether climbing or descending.</li>
<li>Be extra cautious of slopes where wind has deposited deep drifts of snow, or if you witness collapsing or cracking of the snow.</li>
<li>With minimal snow cover, the best skiing is found where snow is drifted deep. Find terrain less steep than ~32 degrees if you are unsure of stability.</li>
<li>Small slides can have high consequences when the snow cover is thin. Traumatic injury is more likely than burial, and can be serious or life-threatening in the backcountry.</li>
<li>Hunters are exposed to avalanche terrain, and often travel alone without avalanche rescue gear. Hunters should avoid travel on or below steep (&gt;32 degrees), snow covered slopes.</li>
<li>Small slopes can slide and bury a person in confined terrain like road cuts, gullies, and creek beds. Avoid terrain traps like these where snow is deep or drifted.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</li>
</ul>

<p>Avalanches have caught and injured skiers, hunters, and climbers during the early-season. Travel and prepare for avalanches like you would in the middle of winter.</p>

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<p>We are getting prepared for winter, scheduling avalanche classes, and setting up weather stations. Drop a line if you get out in the hills and have any avalanche or snow observations to share, e-mail <a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a&gt; or call 406-587-6984.</p>

<p>Cooke City is in uncharted territory. Over the past seven days, this area has received over 8” of SWE (snow water equivalent&lt;) totaling 5-7’ feet of snow. This breaks the seven day record set back in 1986. Yesterday, Alex and his partner dug a snowpit on a NE facing slope around 9,500 ft. and found a snowpack 10’ deep. He noted nearly 5’ was new snow over the past week. The pure weight of this load will push any weakness in the snowpack past its breaking point. Today, continued precipitation in the form of snow and rain will make natural and human triggered avalanches certain. All avalanche terrain including avalanche runout zones should be avoided. Today, the avalanche danger is rated EXTREME !</p>

<p>In the mountains near West Yellowstone including the southern Madison Range, above freezing temperatures and heavy precipitation, mostly in the form of rain, is producing very dangerous avalanche conditions. Yesterday, a snowmobiler triggered a slide up Taylor Fork (<strong><a class="external" href="http://www.mtavalanche.com/images/17/avalanche-near-sunlight-basin&quot; target="_blank">photo</a></strong>) and I found unstable conditions on mid to low elevation slopes near Hegben Lake (<strong><a href="https://www.youtube.com/watch?v=tuXRTgSQ_D0&amp;list=PLXu5151nmAvQF9mZX…;). &nbsp;Today, natural and human triggered wet snow avalanches are likely on all mid to low elevation slopes. These slides have the potential to be large and dangerous. All avalanche terrain and avalanche runout zones should be avoided.</p>

<p>Today, very dangerous avalanche conditions exist and the avalanche danger is rated <strong>HIGH</strong> on all slopes below 9,000 ft. &nbsp;On slopes above 9,000 ft., the dry snow avalanche danger is rated <strong>HIGH</strong> on wind loaded slopes and <strong>CONSIDERABLE</strong> in non-wind loaded terrain.</p>

<p>The northern ranges did not receive nearly as much rain and snow as the southern areas. However, lite rain and above freezing temperatures have produced unstable conditions on mid to low elevation slopes. Currently, freezing levels are around 8,000 ft. Today, continued precipitation in the form of rain and snow will create dangerous avalanche conditions. Manage terrain carefully and avoid being on or underneath steep slopes, especially in mid to low elevation terrain.</p>

<p>Today, a mix of rain and snow combined with above freezing temperatures will make natural avalanches possible and human triggered avalanches likely. For this reason the avalanche danger is rated <strong>CONSIDERABLE</strong> on all slopes.</p>

<p>Alex will issue the next advisory tomorrow morning by 7:30 a.m.</p>