Good morning. This is Ian Hoyer with the Gallatin National Forest Avalanche Forecast on Sunday, January 1st at 7:00 a.m. This information is sponsored by Blitz Motorsports and Yamaha and Avalanche Alliance. This forecast does not apply to operating ski areas.
On December 31, 2022 a snowmobiler was killed in a very large avalanche north of Cooke City. The avalanche occurred near Daisy Pass on Crown Butte on a southeast facing slope at 9,800’. Two riders from Washington were snowmobiling uphill on adjacent slopes. One rider was climbing a steeper slope and triggered the avalanche 100-200’ below the top. He was carried 600 vertical feet and buried 5 feet deep. The buried rider was wearing an airbag pack that was not deployed. Both riders had shovels and probes. They were not wearing avalanche beacons. A nearby group of riders rode up to the slide within minutes after it happened, saw a buried snowmobile and began to search for the rider. One rider from that group went into Cooke City to alert Search and Rescue. The buried rider was located with a probe line an hour after the avalanche happened. He was unable to be revived with CPR and AED at the site. The avalanche appeared to be 2-4' deep, 500' wide, 600' vertical, and broke on weak snow near the bottom of the snowpack. Our deepest condolences go out to the family, friends, and those involved.
Yesterday morning, 1-3” of snow fell across the advisory area, ending by noon. Winds this morning are 5-15 mph out of the north and west. Temperatures are in the high single digits and teens F. Winds will remain light and shift northeast through the day. High temperatures will be in the teens and 20s F. Skies will be mostly cloudy with chances for a few snowflakes to fall, but no significant accumulations.
Yesterday’s fatality is the clearest possible indicator that the snowpack remains capable of producing large and dangerous avalanches (photo, photo). In addition, there were snowmobile triggered slides on Sheep Mountain near Cooke City (video, details) and another along Lionhead ridge (details). These slides all broke on weak layers in the lower snowpack (Taylor Fork video). You could also trigger dangerous slides within the snow that’s fallen over the last week (particularly where it has been wind drifted) or on a weak layer buried just beneath it. Although the snowpack is somewhat shallower in northern areas than further south, the list of concerns is the same. With no new snow or wind drifting, avalanches are a hair less likely today than yesterday, but still very much possible and they will be large.
Once they get a substantial break from the stress of new snowfall these layers will eventually stop producing avalanches, however, we are clearly not there yet. In the meantime, don’t try to outsmart the persistent weak layers. These layers are not producing consistently unstable snowpack test results, but they are producing avalanches. Continued patience (avoiding avalanche terrain) and adherence to safe travel protocols (riding one at a time, carrying rescue gear, and watching your partners for a safe spot) are the best ways to manage this concern.
Human triggered avalanches are possible and the avalanche danger is MODERATE.
Please share avalanche, snowpack or weather observations via our website, email (firstname.lastname@example.org), phone (406-587-6984), or Instagram (#gnfacobs).
In Island Park, slides can break on weak layers in the lower snowpack, within the snow that’s fallen over the last week (particularly where it has been wind drifted) or on a weak layer buried just beneath it. There was an avalanche fatality yesterday near Cooke City and a deep slide triggered along Lionhead ridge. Continued patience (avoiding avalanche terrain) and adherence to safe travel protocols (riding one at a time, carrying rescue gear, and watching your partners for a safe spot) are the best ways to manage these concerns.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
January 4 + field day on January 7 or 8, Avalanche Fundamentals for Snowmobilers, Information and pre-registration HERE.
January 4 + field day, Avalanche Fundamentals for Skiers and Snowboarders, Information and pre-registration HERE.
Every Saturday, 10 a.m. - 2:00 p.m. Avalanche Rescue Training, drop in for any amount of time. Round Lake Warming Hut, Cooke City. Free.
Loss in the Outdoors, is a support group for those who have been affected by grief and loss related to outdoor pursuits. Check out the link for more information.
Please consider donating to the Friends of GNFAC Annual Fundraiser.
There was also an avalanche fatality yesterday in Colorado. Two sidecountry skiers were caught in an avalanche near Breckenridge. One was partially buried, the other fully. After the partially buried skier extricated himself, he was unable to located the other skier. An avalanche rescue dog team found the fully buried (deceased) skier two hours later (preliminary report).