22-23

<p><span><span><span><span><span><span>The mountains around Bozeman and Big Sky picked up 6-9” of fluffy snow measuring .2-.3” of </span></span></span></span></span></span><a href="http://snow.wyo.gov/snow-surveys/snow-water-equivalent-swe"><span><span… water equivalent (SWE)</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>. We like getting new snow, but not when it's accompanied by wind. During the storm W-N wind blew 10-15 mph with gusts of 25 mph at the ridgelines, and it is still blowing. Wind moves snow from one side of the mountain to another and also packs it tightly creating thick, dense slabs. Avalanches are likely to be triggered in these drifts and slopes may even break naturally, without any human help. Snow that is not powdery is likely wind-loaded and should be avoided. Shooting cracks are a sure sign that the recipe for an avalanche is present.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>On slopes without a wind-load conditions will be better, but not perfect. Not much weight was added to the snowpack; however, we have a weak layer of faceted (sugary) snow buried 1-2 feet deep on many slopes that has the potential to avalanche. We found it on </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=XrYqTxRt4go&amp;list=PLXu5151nmAvTi1DBS… Peak</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> and in </span></span></span></span></span></span><a href="https://youtu.be/rRbw4FFs4i0"><span><span><span><strong><span><u><span>…;, and sledders found it on </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27201"><span><span><span><strong><span… Ridge</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>. Dig down and look for this weakness before committing to avalanche terrain, and head to lower-angled slopes if you find it. For today, the avalanche danger is rated CONSIDERABLE on wind-loaded slopes and MODERATE on all others. </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>The southern mountains received 1-2” of snow with the exception of Taylor Fork where 6” (.2 </span></span></span></span></span></span><a href="http://snow.wyo.gov/snow-surveys/snow-water-equivalent-swe"><span><span…;) fell with a light north wind. These mountains have a weak layer of faceted, sugary snow buried 2-3 feet deep which is active. A passing snowmobiler or skier can trigger this weakness which is evident by rumbling whumpfs, an avalanche on the flats. If flatter terrain is connected to steeper slopes an avalanche can be released (a.k.a. remote trigger). On Friday, Alex and his partner triggered a slope in Cooke City this way and posted a video and pictures on our </span></span></span></span></span></span><a href="http://www.mtavalanche.com/index.php/node/27148"><span><span><span><str…; page. On Tuesday, Dave and I were in Lionhead (</span></span></span></span></span></span><a href="https://youtu.be/bKxqg13gn9Y"><span><span><span><strong><span><u><span>…;) while Ian was further north in Bacon Rind (</span></span></span></span></span></span><a href="https://youtu.be/Do5_dVhsw94"><span><span><span><strong><span><u><span>…;). We both had audible whumpfs in the unstable snow. On slopes with wind drifts, this instability will be exacerbated because not only is the layer supporting more weight, but thicker slabs can allow avalanches to break wide. Whumpfs and shooting cracks are Mother Nature’s warning sign to stay off steep slopes. For today, triggering avalanches is possible and the avalanche danger is rated MODERATE.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>If you get out, please share avalanche, snowpack or weather observations via our</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/add/snow_obs"><span><span><span><span>…; </span></span></span></span></span></span><span><span><span><strong><span><u><span><span>website</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, email (</span></span></span></span></span></span><span><span><span><strong><span><span>mtavalanche@gmail.com</span></span></strong></span></span></span><span><span><span><span><span><span>), phone (406-587-6984), or Instagram (#gnfacobs). </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>This morning we are measuring 4” of low density snow and light wind. The snowpack is deep in spots (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=06pszOXXgOQ"><span><span><span><strong>…;) and also has weaker facets buried about 2.5 feet under the surface (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27208"><span><span><span><strong><span…;). Triggering avalanches is possible, especially on slopes that have been wind-loaded. Whumpfs, cracking or collapsing are signs that slopes are dangerous and should be avoided.</span></span></span></span></span></span></p>

<p><br />
<a href="https://www.mtavalanche.com/node/add/snow_obs"><span><span><span><span>… your snow, avalanche and weather obs</span></span></u></span></span></span></span></span></a><span><span><span><span><span><u><span><span>ervations</span></span></u></span></span></span></span></span><span><span><span><span><span><span> to contribute to the </span></span></span></span></span></span><a href="https://www.mtavalanche.com/forecast/centennials"><span><span><span><sp… Park Trip Planning</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> page. &nbsp; </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>In the mountains south of Big Sky to West Yellowstone and Cooke City we are finding weak snow that is buried 2-3 feet deep. These sugary, faceted grains are capped with a stiff wind drift and are showing signs of instability. Alex was surprised by unstable snow in Cooke City (</span></span></span></span></span></span><a href="http://www.mtavalanche.com/index.php/node/27148"><span><span><span><str…;) on Friday, and yesterday in Lionhead both Dave and I, along with Ian in Bacon Rind, and a skier on Kirkwood Ridge (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27199"><span><span><span><strong><span…;), had collapses (whumpfs), which are essentially avalanches on flatter ground. This was our primary sign that slopes harbored instability. As Ian pointed out in his video, there’s no need to dig snowpits searching for instability when whumpfs are felt (</span></span></span></span></span></span><a href="https://youtu.be/Do5_dVhsw94"><span><span><span><strong><span><u><span>…;).&nbsp;&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>A poor snow structure of thicker, meatier slabs of snow being supported by a weak layer plagues the southern mountains. Our </span></span></span></span></span></span><a href="http://www.mtavalanche.com/index.php/snowpits"><span><span><span><stron…; illustrate this and we found it again yesterday in Lionhead (</span></span></span></span></span></span><a href="https://youtu.be/bKxqg13gn9Y"><span><span><span><strong><span><u><span>…;). Since natural avalanches are unlikely and triggering them is thankfully not guaranteed, we can still get out and have fun on shallow angled slopes. Whumpfs and poor test scores tell us we need to travel with caution. Yesterday, we chose not to get on steep slopes and carefully crossed runout zones one at a time. For today, avalanches remain possible and the danger is rated MODERATE. </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Wind-drifted slopes remain a concern in the mountains around Bozeman and Big Sky. </span></span></span></span></span></span><a href="http://www.mtavalanche.com/index.php/weather/wx-avalanche-log"><span><s… activity</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> on Saturday in the northern mountains illustrate a lingering problem. On Sunday, Alex and his partner found thick wind drifts perched atop weaker snow on Saddle Peak (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=XrYqTxRt4go&amp;list=PLXu5151nmAvTi1DBS…;. This structure is reminiscent of years past when we had large avalanches later in the season. It was also similar to the instability I found in the gullies up Hyalite (</span></span></span></span></span></span><a href="https://youtu.be/rRbw4FFs4i0"><span><span><span><strong><span><u><span>…;). On Buck Ridge a group of sledders also found weak snow under wind slabs (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/27201"><span><span><span><strong><span…;).&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Dave went to Mount Ellis on Monday and found relatively stable snow on his tour (</span></span></span></span></span></span><a href="https://youtu.be/TkUux4F7dV8"><span><span><span><strong><span><u><span>…;). No matter where you head to, it’s a good idea to test the slope you want to play on. Dig a pit, look for instability and back off if you find it. We have a recent history of avalanches and we are still finding buried weak layers breaking in our stability tests. Consequently, the danger is rated MODERATE.&nbsp;</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>If you get out, please share avalanche, snowpack or weather observations via our</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/add/snow_obs"><span><span><span><span>…; </span></span></span></span></span></span><span><span><span><strong><span><u><span><span>website</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, email (</span></span></span></span></span></span><span><span><span><strong><span><span>mtavalanche@gmail.com</span></span></strong></span></span></span><span><span><span><span><span><span>), phone (406-587-6984), or Instagram (#gnfacobs). </span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>We are finding weak snow that is buried 2-3 feet deep. These sugary, faceted grains are capped with a stiff wind drift and are showing signs of instability. Since natural avalanches are unlikely and triggering them is thankfully not guaranteed, we can still get out and have fun on shallow-angled slopes. Whumpfs and poor test scores tell us we need to travel with caution. Yesterday, we chose not to get on steep slopes and carefully crossed runout zones one at a time. Check out Friday’s Yale Creek Drainage </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=06pszOXXgOQ"><span><span><span><strong>… video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span> for more specific information.&nbsp;</span></span></span></span></span></span></p>

<p><a href="https://www.mtavalanche.com/node/add/snow_obs"><span><span><span><span>… your snow, avalanche and weather obs</span></span></u></span></span></span></span></span></a><span><span><span><span><span><u><span><span>ervations</span></span></u></span></span></span></span></span><span><span><span><span><span><span> to contribute to the </span></span></span></span></span></span><a href="https://www.mtavalanche.com/forecast/centennials"><span><span><span><sp… Park Trip Planning</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span> page. &nbsp; </span></span></span></span></span></span></p>