Snowpack and Avalanche Discussion
<p><span><span><span><span><span><span>Both human triggered and natural avalanches are likely today. Heavy, dense new snow is overloading a weak snowpack. 8” of new snow may not seem like much, but it is between 2x and 4x as dense as our more typical snowfall (it contains 1.6” of </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observat… water equivalent</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>, 2.1” fell in the last 48 hours). The weight of this new snow will overload the weak layers in the upper snowpack that are 1.5-2.5 ft deep and may also wake up the weak layers near the base of the snowpack (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=rAwOu4SFTBc"><span><span><span><strong>…;). Yesterday, we encountered deep wind drifts near the head of Yale Creek (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31087"><span><span><span><strong><span…;). These drifts are magnifying the weight of the new snow, making conditions even more unstable. Extremely strong winds have created drifts at all elevations. Large avalanches are likely and really gigantic avalanches breaking at the bottom of the snowpack are also possible. Avoid all slopes steeper than 30 degrees and avoid crossing beneath them as well. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is HIGH today.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>New snow and wind on a weak snowpack means human triggered avalanches are likely today. More snow fell around West Yellowstone and Cooke City last night with more snow expected today, but the Bozeman and Big Sky areas were the big winners yesterday, so it balances out and you should expect all areas to have dangerous conditions. Avalanches could break beneath the new and wind drifted snow or on the weak layers deep in the snowpack. Smaller avalanches in the new snow could also step down to trigger deeper slides.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Riders in the northern Bridger’s yesterday noted fresh natural avalanches (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31084"><span><span><span><span><span><…;) and riders near Lionhead were able to make small avalanches in the new snow on test slopes (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31099"><span><span><span><strong><span…;).</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Drifts that formed during yesterday’s apocalyptically strong winds have now been hidden underneath a fresh blanket of new snow drifting with more normal, but still strong winds. This will make wind loading patterns even harder to identify.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Give the new snow time to stabilize and wait to see how the deeper weak layers handle this loading event before getting onto steep slopes. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is CONSIDERABLE.</span></span></span></span></span></span></p>
Upcoming Avalanche Education and Events
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