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Natural avalanche observed on Monday (4/10) in northern Bridger Range. New snow and wind over the weekend created unstable dry slabs. This avalanche appears to be triggered by a cornice fall and is up to approx.3 feet deep. Similar slides can be triggered by a skier or rider, and are most likely during or immediately following storms. Photo: J. Schmitt

Bridger Range, 2017-04-12
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    • Natural avalanche observed on Monday (4/10) in northern Bridger Range. New snow and wind over the weekend created unstable dry slabs. This avalanche appears to be triggered by a cornice fall and is up to approx.3 feet deep. Similar slides can be triggered by a skier or rider, and are most likely during or immediately following storms. Photo: H. Haselton

    Bridger Range, 2017-04-11
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    • This avalanche was in Hidden Gully at the top of the Apron at Bridger Bowl. New snow avalanches along with wind-loading and cornice falls are part of the dangers at Bridger Bowl since the ski area is closed and ski patrol is not doing control work. Although it may feel safe because the terrain is so familiar, backcountry avalanche conditions exist. Photo: B. Balkin

    Bridger Range, 2017-04-11
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    • GNFAC Avalanche Forecast for Sat Apr 8, 2017

    Snowpack and Avalanche Discussion

    <p>Above freezing temperatures yesterday followed by rain and snow create a mix of spring snow conditions today.&nbsp;Before rain and snow fell last night the snowpack was wet and not frozen up to 10,000’ near Bozeman. New snow insulates weak unconsolidated snow where the snowpack did not freeze. The weight of rain and new snow today, or a small loose snow avalanche could trigger a deeper wet avalanche. Natural avalanches are possible with rain or snow today. Avoid steep terrain if the snowpack is wet and not supportable below the new snow, and be cautious of runout zones and&nbsp;steep terrain overhead during precipitation.</p>

    <p>Dry loose avalanches are possible in steeper terrain and could propagate wide or run far where a firm crust underlies new snow. Overall, I expect last night’s snow bonded well to a warm snowpack, and light wind today will not form fresh drifts of snow. Yesterday, a skier on the long un-motorized journey into Hyalite saw strong wind knock down trees across the road. Eric was in Beehive and experienced strong winds, but minimal slab formation and an overall stable snowpack. Small drifts of snow are isolated and difficult to trigger today, but are possible and should be avoided or approached with extra caution in high consequence terrain.</p>

    <p>Today, the avalanche danger is MODERATE and could rise to CONSIDERABLE if there is heavy rain and snow this afternoon.</p>

    <p>As the weather changes daily, so do our avalanche concerns. Check out Doug’s <a href="https://youtu.be/6lvWhMiAXWs"><strong>video</strong></a&gt; or my <strong><a href="http://www.mtavalanche.com/blog/transitions-spring-snow-avalanche-probl…; </strong>for more information on spring snow avalanche problems and travel advice.</p>

    <p>I will issue our last advisory of the season tomorrow morning by 7:30 a.m.</p>

    We rely on your field observations. Send us an email with simple weather and snowpack information along the lines of what you might share with your friends: How much new snow? Was the skiing/riding any good? Did you see any avalanches or signs of instability? Was snow blowing at the ridgelines? If you have snowpit or test data we'll take that too, but this core info is super helpful! Email us at mtavalanche@gmail.com or leave a message at 406-587-6984.

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