19-20

<p>Across our whole advisory area the snowpack is generally stable, but that will change as the day heats up.</p>

<p>The new snow that fell this week has generally bonded well to the old snow surface. Still, pay attention to this interface and make sure you don’t find an isolated pocket where it hasn’t, especially where the new snow has been blown into deeper drifts. Also, check to see if there is surface hoar hiding under the new snow. Surface hoar (<a href="https://www.mtavalanche.com/images/20/surface-hoar-near-buck-ridge"><st…;) formed in many areas earlier in the week. So far we’ve only had one report of someone finding it buried, near Henderson Mountain north of Cooke City. <a href="https://mtavalanche.us17.list-manage.com/track/click?u=6653a830e4819c9e… in touch</a> and let us know if you do (or don’t) find it when you’re out today, so we can better map its distribution. In places where was the surface hoar was buried, the new snow will avalanche more easily and take longer to stabilize. Either way, watch for shooting cracks as a clear sign the new snow remains unstable.</p>

<p>With warmer temperatures today and a strong springtime sun, conditions will change rapidly. Watch out for the snow surface becoming sticky and wet. It will only take a few hours of unobscured sun to start melting the snow surface. If you begin to see pinwheels and rollerballs, it’s time to move off of steep sunny slopes. New snow getting direct sun for the first time will slide easily on widespread buried ice crusts (<a href="https://youtu.be/ZjWC31nMPmg"><strong>video</strong></a&gt;). These slides won’t break very deep, but could be hazardous in higher consequences terrain where a small slide could push you over rocks and cliffs or into trees.</p>

<p>Yesterday I toured in the northern Bridger’s and found stable avalanche conditions, but difficult and dangerous riding conditions on many aspects (<strong><a href="https://www.youtube.com/watch%3Fv=3V0VTHc9YC8%26list=PLXu5151nmAvSbcbVf…;). Avalanches are only one of many hazards in the mountains. Tweaking your knee in a breakable crust or an uncontrolled fall on firm snow in the morning are also real concerns. Plan ahead so you don’t get stuck deciding between hazardous riding conditions and hazardous avalanche conditions. Always make sure that you have a viable, safe, escape route if your intended plan falls through.</p>

<p>The avalanche danger is LOW this morning, but will rise to MODERATE on sunny slopes as the day heats up and wet avalanches become possible.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an observation form, email us (mtavalanche@gmail.com), leave a VM at 406-587-6984, or Instagram (#gnfacobs).</p>

<p>The mountains around Cooke City picked up 5” in the last 24 hours. Over 2 feet of snow measuring 2” of <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/or/snow/?cid=nrcs142p2… water equivalent</a> has fallen since Sunday. Winds have been unusually light. Our main concern is the new and old snow interface since Tuesday when a layer of surface hoar crystals (feathers of snow) was formed. Yesterday, skiers found it on slopes that remained shady (north facing) in the Fisher, Miller and Wolverine areas. Shooting cracks are a sign that it is underfoot and could avalanche. In the absence of cracking, it’s a good idea to dig with your hand a few inches under the surface to see if it’s there. On many slopes a buried ice crust is allowing new, loose snow avalanches to travel far. Given yesterday’s snow, a buried weak layer scattered about, and the potential for sunny skies and melting snow, the avalanche danger is rated MODERATE since avalanches are possible today.</p>

<p>From the Bridger Range to West Yellowstone, the mountains received up to an inch of new snow with calm to light wind. Today will be mostly cloudy, temperatures will be cool and wet avalanches will be an afterthought. In general the snowpack is stable. Slopes that have received sun and melting earlier in the week have an ice crust a few inches under the surface (<strong><a href="https://www.mtavalanche.com/images/20/bacon-rind-meadow-pit">photo</a><…;). Skiers on Hardscabble Peak in the Bridger Range were able to sluff the new snow on this crust. I was in Bacon Rind yesterday and found relatively stable snow and noted how the ice crusts will help avalanches slide far when the snow gets wet in the coming days (<strong><a href="https://youtu.be/ZjWC31nMPmg">video</a></strong&gt;).</p>

<p>A thin layer of surface hoar was formed on Tuesday, before the most recent snow, in Hyalite, Beehive and near Big Sky. These are the areas we know of. These feathery crystals (<strong><a href="https://www.mtavalanche.com/images/20/surface-hoar-near-buck-ridge">pho…;) make a persistent weak layer that will be seen as a stripe in the snow. We are still determining if they survived burial and if they will become a problem. Drop us a line if you find them.</p>

<p>For today, avalanches are unlikely and the danger is rated LOW. If, contrary to the weather forecast, the sun appears and wets the surface snow, the wet snow avalanche danger will rise accordingly.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an <u><a href="https://mtavalanche.us17.list-manage.com/track/click?u=6653a830e4819c9e…; target="_blank">observation form</a></u>, email us (<u><a href="mailto:mtavalanche@gmail.com&quot; target="_blank">mtavalanche@gmail.com</a></u>), leave a VM at 406-587-6984, or Instagram (#gnfacobs).</p>