21-22

<p>Triggering large avalanches remains possible in the mountains around Cooke City. Last weekend’s snowfall and continuing wind drifting have loaded a weak layer buried around a foot and a half under the snow surface (<a href="https://www.youtube.com/watch?v=EQDLaHsyinU"><strong><u>video</u></stro…;). This weak layer is categorized as<em> persistent</em>, which means it will stick around and remain an issue for quite a while after being loaded. Winds this morning are the strongest they’ve been since the last snowfall. More snow is being transported and drifting into thicker slabs which could be triggered today. The snowfall forecast today is uncertain, but any new snow will add to the snow available for transport and drifting. Look for collapses, shooting cracks, and especially recent avalanches, as clear signs to avoid avalanche terrain. Large avalanches are possible and the avalanche danger is rated MODERATE.</p>

<p>Conditions are generally stable and large avalanches are unlikely across the rest of the advisory area. The primary concern is a weak layer 12-18” under the surface. While this weak layer is widespread it is only unstable in isolated areas where wind drifting has capped it with a dense slab of snow. The small avalanche that killed a snowmobiler last Sunday in Lionhead is a pointed reminder to stay on alert even when avalanches are unlikely (<a href="https://www.mtavalanche.com/accident/22/02/09"><strong><u>details</u></…;). Yesterday in the northern Bridger Range I found a snowpack that had been hammered by the wind (and stripped to dirt in many places), leaving generally stable conditions until it snows next (<a href="https://www.youtube.com/watch?v=g_EceIGw-UY"><strong><u>video</u></stro…;

<p>Keep your eyes open for signs of instability and keep adhering to safe travel practices as insurance in case you get surprised by an isolated instability. Always carry rescue gear (beacon, shovel, probe). Go one at a time on steep slopes. And keep an eye on your partners while they’re on those steep slopes. For today the avalanche danger is rated LOW in the mountains from Bozeman to West Yellowstone.&nbsp;</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

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<p>It remains possible to trigger avalanches in the mountains around Cooke City. The reason is two-fold. <u>First</u>, there is a buried weak layer of sugary, faceted snow (and surface hoar) a foot and a half under the surface. This layer is responsible for many days of collapses, cracks, avalanches and poor test scores in snowpits (<a href="http://www.mtavalanche.com/avalanche-activity"><strong><u>details</u></…;). Yesterday a skier felt large collapses south of town in Wyoming Creek (<a href="https://www.mtavalanche.com/node/25807"><strong><u>details</u></strong>…;). This matches the concerns Alex had during his visit this week (<a href="https://youtu.be/EQDLaHsyinU"><strong><u>video</u></strong></a&gt;). <u>Second</u>, it has been windy enough to move snow around which loads slopes even when it is not snowing.&nbsp;</p>

<p>Collapses (whumpfs), shooting cracks, and the mother of bulls-eye information, avalanches, are blinking signs to avoid avalanche terrain. Even without those signs, remember to only expose 1 person at a time to avalanche terrain. For today the avalanche danger is rated MODERATE on all slopes.</p>

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<p>Last night’s minor snowfall around Big Sky and Hyalite will not affect the general stable conditions we are finding in the mountains from Bozeman to West Yellowstone. Weak layers of small, sugary facets and two stripes of feathery surface hoar crystals can be found 12-18” under the surface (<a href="https://www.mtavalanche.com/images/22/2-surface-hoar-layers"><strong><u…;, <a href="https://www.mtavalanche.com/images/22/bacon-rind-profile-9-feb-22"><str… profile</u></strong></a>). This layer is widespread yet only unstable in small, isolated areas where wind drifting has capped it with a dense slab of snow. This recipe is what allowed a snowmobiler to trigger a small but deadly slide on Sunday in Lionhead (<a href="https://www.mtavalanche.com/accident/22/02/09"><strong><u>details</u></…;). Once snowfall resumes, this weak layer will become unstable over wide swaths of our forecast area, but until then, avalanches are unlikely. Even with a stable snowpack we have to keep up our safety rituals. Just like buckling a seat-belt for a short drive, we need to always carry our rescue gear (beacon, shovel and probe) and literally only expose one person at a time in avalanche terrain. For today the avalanche danger is rated LOW on all slopes.&nbsp;</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our <a href="https://www.mtavalanche.com/node/add/snow_observation"><strong><u>websi…;, email (<a href="mailto:mtavalanche@gmail.com"><strong><u>mtavalanche@gmail.com</u></str…;), phone (406-587-6984), or Instagram (#gnfacobs).</p>

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