Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Saturday, February 24th at 7:00 a.m. Today’s forecast is sponsored by Cooke City Motorsports, Bridger Bowl and Beartooth Powder Guides. This forecast does not apply to operating ski areas.
This morning there is 1” of new snow near West Yellowstone, and no snow elsewhere. Temperatures are teens to high 20s F. Wind has been 10-25 mph with gusts of 25-70 mph from the west-southwest. Today, under partly sunny skies, temperatures will reach high 20s to low 30s F, and wind will remain moderate to strong out of the west at 15-25 mph with gusts of 25-60 mph. Tonight a few snow showers could drop a trace to 1” near Cooke City and the Bridger Range with none elsewhere. The next snow event is expected late Sunday through Monday.
Yesterday near Cooke City a snowmobiler triggered a large avalanche, was caught and carried, but luckily not buried or injured. At the same time another avalanche released sympathetically on an adjacent slope (photos). Also yesterday, near Big Sky a pair of riders triggered two avalanches from flatter slopes nearby (photos and details). These avalanches show dangerous conditions exist. Today people can easily trigger large avalanches, potentially from flatter terrain below steep slopes.
Over the last week 3-5” of snow fell near Big Sky, West Yellowstone, Island Park and Cooke City, and even this little amount of snow has prevented the unstable snowpack from gaining strength. Moderate to strong wind yesterday and today drifted snow into thicker slabs, keeping the snowpack especially unstable on wind-loaded slopes.
This season’s snowpack is unique. Typically a snowpack becomes more stable over time with minimal snowfall or wind-loading. However, we have seen steady avalanche activity since early January, even during times without new snow or wind (weather and avalanche log). Weak layers of facets and surface hoar buried 2-4 feet deep make up the foundation of the snowpack, and are as weak as we’ve seen. The snowpack needs to show proof it has changed before we can begin to trust it, and that has not happened. The best plan is to avoid riding on or beneath slopes steeper than 30 degrees. Avalanche danger is CONSIDERABLE.
In the Bridger Range and Hyalite there has been less recent snow and avalanches, showing the likelihood of triggering an avalanche is slightly lower compared to the rest of our forecast area. However, the snowpack has weak, sugary snow trying to support overlying slabs, and it remains possible for a person to trigger a large avalanche. Avalanches last weekend in the Bridgers, near Bridger Peak and south of Saddle Peak, and on Mt. Bole in Hyalite are examples of the avalanche potential.
If you consider stepping into steeper terrain, start with smaller, simple slopes that don’t have recent wind loading and have good runouts below. Look for signs of instability and perform snowpack tests, and be ready to change plans if you see any red flags. Watch Ian’s video from the Throne and Dave’s video from Hyalite for more travel and snowpack assessment tips during these conditions. Today, buried weak layers make large, human triggered avalanches possible, and the avalanche danger is MODERATE.
If you venture out, please fill an observation form. It does not need to be technical. Did you see any avalanches? How much snow is on the ground? Was the wind moving snow? Simple observations are incredibly valuable. You can also contact us via email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Friday evening and Saturday (tonight and tomorrow), February 23 and 24. Companion Rescue Course. More information and registration HERE.
Friday evening and Saturday, March 1 and 2. Companion Rescue Course. More information and registration HERE.
March 8-10. Bozeman Splitfest. Check the Bozeman Splitfest website for event details and avalanche education opportunities offered by the Friends of the Avalanche Center.
Every weekend in Cooke City: Friday at The Antlers at 7 p.m., Free Avalanche Awareness and Current Conditions talk, and Saturday from 10 a.m.-2 p.m. at Round Lake Warming Hut, Free Rescue Practice.
Loss in the Outdoors is a support group for those affected by loss and grief related to outdoor pursuits. Check out the link for more information.
On Thursday Ian rode in the Independence Mine area (up the Main Boulder, outside our advisory area) to check out the snowpack conditions before the Sweet Grass County Recreation Association Poker Ride tomorrow. Watch our video for a snowpack update. Avoiding riding on and staying out from under slopes steeper than 30 degrees would be a wise choice if you’re headed up to join in the fun this weekend.