GNFAC Avalanche Forecast for Wed Jan 17, 2024

Not the Current Forecast

Good morning. This is Dave Zinn with the Gallatin National Forest Avalanche Forecast on Wednesday, January 17th at 7:00 a.m. This information is sponsored by the Avalanche Alliance and the Idaho State Snowmobile Association - Avalanche Fund. This forecast does not apply to operating ski areas.

Mountain Weather

Mountain temperatures are in the single digits to teens F this morning, with 15-30 winds from the west to the south. As of 6 a.m., there is 1-2” of new snow from Big Sky through the southern portions of the advisory area, and it is just beginning to snow in the mountains near Bozeman. Today, temperatures will be in the 20s F with 15-30 mph winds from the west to southwest. By tomorrow morning, the mountains around Cooke City will receive 10-14” of new snow, with 4-8” in Island Park and West Yellowstone and 3-6” around Bozeman and Big Sky.

Snowpack and Avalanche Discussion

New and wind-drifted snow will load persistent weak layers buried throughout the mountains near Cooke City, West Yellowstone, and Island Park, making avalanche conditions more dangerous. Human-triggered avalanches are likely. Slides will break 1-2 feet deep, be large enough to bury or injure backcountry travelers, and may be triggered from on or near steep slopes.

Yesterday, Doug and Ian rode at Lionhead, triggering collapses and shooting cracks, noting “heads up” conditions and recommending travelers avoid crossing the lower portions of avalanche paths (runout zones) once it begins snowing (video). In Cooke City on Sunday, a rider triggered an avalanche that barely missed him as he crossed below a steep slope on Sheep Mountain (video). On Monday in Lionhead, a group triggered an avalanche from twenty feet away (photos and details). Others saw widespread collapsing and cracking that shot 200 feet from their sleds (observation, observation 2). Watch this video from Lionhead at minute 10:30 for a remarkable example of the shooting cracks. A skier south of Cooke City noted many collapses, but one on a low-angle slope shot cracks out 100 feet that then “circled back in a big loop! It was a 3-second symphony of movement in the snow” (photos and details). Equate these observations from Cooke City and Lionhead to Island Park and the Southern Gallatin and Southern Madison Ranges, where the snowpack and recent loading patterns are similar (Taylor Fork video, Centennials video).

Human-triggered avalanches will become more likely as snow falls today. Safely avoid avalanches by traveling on slopes less than 30 degrees without steep terrain above. Careful route-finding, snowpack assessment, and conservative decision-making are essential for travel on and around steeper slopes. The danger is rated CONSIDERABLE.

Human-triggered avalanches are possible in the mountains around Bozeman and Big Sky. They are most likely on slopes recently loaded with wind-drifted snow or where cohesive slabs rest on persistent weak layers (Beehive video, Blackmore video). An observation and photos of two natural avalanches near Divide Peak highlight the concern about wind-loaded slopes. Seek wind-sheltered terrain and assess the snowpack before traveling on slopes steeper than 30 degrees.

Watch for signs of increasing instability as today’s storm progresses. These could include natural avalanches, shooting cracks or collapsing. If observed, avoid avalanche terrain.

The danger is rated MODERATE but will rise to CONSIDERABLE if daytime snow totals exceed forecast amounts.

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 (, 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.

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.

We offer Avalanche Fundamentals with Field Session courses targeted towards non-motorized travelers in January and one geared towards motorized users. Sign up early before they fill up.

TOMORROW, January 18, 4 p.m., Darren Johnson Avalanche Education Memorial Fund - Pint Night, Beehive Basin Brewery, Big Sky. Information HERE.

King & Queen 2024, 3 February 2024. Form a team or sign up individually to hike laps on the Bridger Bowl ridge to fundraise for the Friends of the Avalanche Center.

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.


Do you like to hike? Do you like to ski? Then the King & Queen of the Ridge is for you. Hike, ski and raise money for the Friends of the Avalanche Center in their 2nd biggest fundraiser of the year. Join the effort to promote and support avalanche safety and awareness! Fundraising prizes for the top 5 individuals who raise over $500. No racing is necessary to compete for the fundraising prizes. Info is HERE. Race participants for the February 4th event must register separately with Bridger Bowl HERE.

The Last Word

On Sunday, a skier was killed in an avalanche in the Salt River Range, Wyoming. This is the third avalanche fatality of this season all of which occurred last week (avalanche near Lookout Pass in Idaho, avalanche at Palisades Tahoe in California).

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