21-22

<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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<p>Alex has been in Cooke City since Sunday after 12-14” fell; lucky boy. He and others noted natural and human triggered avalanches under the new snow where a thick layer (6+”) of weak snow (facets and surface hoar) continues to show signs of instability. Our <a href="http://www.mtavalanche.com/avalanche-activity"><strong><u>Avalanche Activity List</u></strong></a> documents 9 events in one week. Yesterday, as Alex skied, he witnessed shooting cracks, a whumpf and another day of propagating test scores in his <a href="http://www.mtavalanche.com/snowpits"><strong><u>snowpits</u></strong></…;. His latest <a href="https://youtu.be/EQDLaHsyinU"><strong><u>video</u></strong></a&gt; is an instructive show-and-tell of avalanche concerns.&nbsp;</p>

<p>Before Friday and Saturday’s storm, stability was good and people were feeling comfortable getting into serious avalanche terrain. Today, not so much. Avalanches are possible on the same slopes that were stable a week ago. We have a significant weak layer that has 1.5 feet of snow on top of it. Any slope that has a wind-load will be especially worrisome. Change objectives and stay clear of avalanche terrain at the first sign of instability, like Alex did yesterday. The weak layer is not going away and slopes still need time to adjust to the added weight of the weekend’s snow. For today, the avalanche danger is rated MODERATE on all slopes.</p>

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<p>The snowpack from the Bridger Range to West Yellowstone is generally stable. Most slopes have weak, sugary snow (and/or feathery surface hoar crystals) buried 18” under the surface. Without the weight of new snow this layer will remain dormant, but there are a few exceptions. Sprinkled throughout the forecast area are small, unstable slopes from wind drifting. Thicker, meatier drifts of snow could break on this weak layer. This is what occurred in Lionhead on Sunday. A snowmobiler triggered a small, shallow and very steep wind-loaded slope that carried him into trees and buried him (<a href="http://www.mtavalanche.com/node/25766"><strong><u>details</u></strong><…;). Even in a sea of stability there are a few shoals of danger lurking. There always are. A telltale sign of instability associated with wind-loading are cracks shooting out from skis or a sled. For today, given the lack of new snow and overall stability, avalanches are unlikely and the danger is rated LOW.&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>