Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Sunday, December 8th at 7:00 am. This information is sponsored by Bozeman Ice Festival, Stronghold Fabrication and Bridger Bowl. This forecast does not apply to operating ski areas.
Cold air is moving into our region this morning. At 6am, temperatures are teens to 20s F, and there is 1-2” of new snow near Cooke City, Big Sky, West Yellowstone and Island Park with no snow in the Bridger Range and Hyalite. Winds are strong at 10-30 mph with gusts of 40-75 mph out of the southwest-northwest. Today, temperatures will drop to the 20s and teens F with moderate to strong wind out of the west-northwest. More snow will fall this afternoon through tomorrow. By tomorrow morning the mountains near Bozeman could receive 6-12” of low density snow with 3-6” elsewhere.
New snow will be drifted into fresh slabs along ridgelines and below rollovers and avalanche danger will slowly rise through the day. Wind slab avalanches are the primary problem and will probably be less than 6-8 inches deep and relatively small. However, fresh drifts will be deposited on weak layers making them easy for a person to trigger.
On many slopes the snow surface became weak during the past week of high pressure. See our recent videos from Lionhead, Buck Ridge, Taylor Fork, Cooke City for a look at what lies on the ground. Expect fresh drifts to be unstable today. Cracking across the snow surface or natural avalanches are a clear sign that you can trigger an avalanche. Even a small slab can easily carry you, so be especially cautious in terrain with higher consequences.
If you are skiing or riding slopes steeper than 30 degrees, or ice-climbing in steep gullies, steer clear of fresh drifts, and keep in mind the increased risk of even a small slide due to thin snow cover, or being pushed over cliffs or into rocks or trees.
On slopes without fresh drifts avalanches are unlikely. Weak layers are buried near the bottom of a 1-2 foot deep snowpack, but probably need more than the weight of today’s new snow before they are a potential or more widespread problem. Quickly dig to assess for buried weak layers before committing to a steep slope, carry proper rescue gear, and travel one at a time across steep slopes.
Fresh wind slabs will grow today and the avalanche danger is MODERATE on wind-loaded slopes and LOW on non-wind loaded slopes.
In the Bridger Range and Hyalite snowfall is forecast to begin later, and without fresh snow avalanches are unlikely today. Quickly dig to assess for buried weak layers before committing to a steep slope, carry proper rescue gear, and travel one at a time across steep slopes. If snowfall begins earlier than expected, or if you are out after dark, watch for fresh wind slabs to form and expect them to be easy to trigger. Avalanche danger is LOW.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar
Tuesday, December 10, 9 a.m.-3 p.m., West Yellowstone Avalanche Fundamentals: Motorized Guide Cert Course, Pre-registration required.
For an intro class with a field day, Register for our Avalanche Fundamentals course.
*Bridger Bowl has backcountry conditions and there are no ski patrol services. Please steer clear of snowmaking equipment, chairlifts and snowmobiles, and respect posted signage while they set up for the season.*
Friends of the Avalanche Center: Fall Fundraiser!
We’re still counting on your support and the online Fall Powder Blast fundraiser is 79% of the way to our goal. Please consider making even a small donation HERE or via Venmo