21-22

From email 3/13/22: "Noticed these small breaks all over the zone [on 3/12/22], mostly on south facing slopes, along with cracking near them. Easily triggered as well as lots of natural breaks. This one was just west of round lake, south facing:" Photo: S. Strenge

Avalanche Details: Many natural 6-10" deep avalanches near Cooke
Forecast link: GNFAC Avalanche Forecast for Mon Mar 14, 2022
Cooke City, 2022-03-13
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    • Wet Loose evidence in Banana Couloir

    Date
    Activity
    Snowboarding

    Skied Banana Couloir yesterday off of Ross Peak in the Bridgers. On our approach the sun was intense and quickly saturated the upper snowpack. In the sun and out of the wind the air temperature was probably around 50 degrees fahrenheit. When skinning over small hills we were able to get the top 2-3 inches of snow to slide on the thick crust below which made us concerned about a possible wet slab issue. We got one to slide the full length of a small hill, about 25 feet. 

    The clouds rolled in, temps dropped, and the saturated snow on top strengthened  and resolidified. Booting up the Banana Couloir we saw some debris from a small wet loose slide and large pin wheels that had happened earlier when the sun was out. When we got back to the car we noticed that a lot of snow at lower elevations had melted out in the sun that day. 

    Region
    Bridger Range
    Location (from list)
    Ross Peak
    Observer Name
    Connor Culver

    GNFAC Avalanche Forecast for Sun Mar 13, 2022

    Snowpack and Avalanche Discussion

    <p>Today near Cooke City&nbsp;dangerous avalanche conditions will develop on slopes that are being loaded by wind-drifted snow. Yesterday we saw at least seven natural and human triggered, small avalanches which broke 6-10” deep and relatively wide on a hard melt-freeze crust (<a href="https://www.mtavalanche.com/node/26166"><strong><u>details and photos</u></strong></a>, <a href="https://www.mtavalanche.com/node/26165"><strong><u>details and photos</u></strong></a>). A few more inches of snow through today with moderate to strong southwest winds will grow thicker slabs and make large avalanches likely on wind-loaded slopes. Avalanches can potentially break deeper and wider on weak layers buried over 2 feet deep (<a href="https://www.youtube.com/watch?v=beIj2Ar5_yk&amp;list=PLXu5151nmAvT1nrM2… Butte video</u></strong></a>, <a href="https://www.youtube.com/watch?v=BGiz4qC7pQg"><strong><u>Scotch Bonnet avalanche video</u></strong></a><strong>)</strong>. Today, avoid steep wind-loaded slopes, and before riding any steep slopes carefully assess the snowpack for potential instabilities. Avalanche danger is CONSIDERABLE on wind-loaded slopes and MODERATE on all other slopes.</p>

    <p>Yesterday in the northern Bridger Range a snowboarder triggered and was caught in an avalanche that broke 4-8” deep and 100 feet wide. They were not injured (<a href="https://www.mtavalanche.com/node/26170"><strong><u>photos and details</u></strong></a>). Another group had slabs of snow cracking around their skis and retreated from steep terrain (<a href="https://www.mtavalanche.com/node/26171"><strong><u>details</u></strong>…;). Near Bozeman and Big Sky, over the last 72 hours strong west-southwest winds drifted snow into dense slabs that can still be triggered by a person today. Near West Yellowstone and the southern Madison Range, wind increased over the last 24 hours and formed similar fresh drifts that are possible to trigger. These slabs may be unstable where they sit on a hard melt-freeze crust or soft, sugary weak facets (<a href="https://www.youtube.com/watch?v=ulXRgmKlrRw"><strong><u>Lionhead video</u></strong></a>, <a href="https://www.youtube.com/watch?v=5o-XoWhmTcU&amp;list=PLXu5151nmAvT1nrM2… Creek Video</u></strong></a>). Before riding steep slopes, carefully assess the snowpack for buried weak layers and avoid slopes where you see signs of snow that was recently blown into thick drifts or slabs. Avalanches are possible to trigger and avalanche danger is MODERATE on wind-loaded slopes and LOW on other slopes.</p>

    <p>If you get out, please send us your observations no matter how brief. You can submit them via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).</p>

    Upcoming Education Opportunities

    See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events.

    Every Saturday near Cooke City, 10 a.m.-3 p.m. FREE snowpack update and transceiver/rescue training. Stop by for 20 minutes or more at the Round Lake Warming Hut.

    Shooting Cracks Ross Peak

    Ross Peak
    Bridger Range
    Code
    Latitude
    45.85860
    Longitude
    -110.95600
    Notes

    From obs 3/12/22: "A group of four of us were hoping to ski the banana couloir on Ross Peak today, knowing wind loading would likely be an issue. We approached from the east (?) ridge, and gained enough elevation to cross the face towards the entrance of the line. Upon exiting the protected ridge towards the face (about ~100 ft from the entrance to the banana) we experienced shooting cracks on the heavily cross loaded slope. The wind was blowing heavily and swirling, coming predominately out of the Southwest, which was odd. We decided to turn around and enjoy some highly variable meadow skipping  back to the car."

    Number of slides
    0
    Number caught
    0
    Number buried
    0
    Problem Type
    Wind-Drifted Snow
    Slab Thickness units
    centimeters
    Single / Multiple / Red Flag
    Red Flag
    Advisory Year
    21-22
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