GNFAC Avalanche Forecast for Thu Jan 7, 2021

Not the Current Forecast

Good Morning. This is Doug Chabot with the Gallatin National Forest Avalanche Forecast on Thursday, January 7th at 7:30 a.m. This forecast is sponsored by Summit Motorsports and Ski-Doo and Montana Chevy Dealers. This forecast does not apply to operating ski areas.

Mountain Weather

At 6 a.m. it is snowing and 1-2 inches has fallen in Taylor Fork, Big Sky and Bridger Range.  Winds are SW at 10-20 mph with gusts of 30 mph and temperatures are in the high teens to low 20s F. Today, winds will remain moderate from the SW and 2-4” of snow will fall in the north and 1-2” around West Yellowstone and Cooke City. Temperatures will reach the high 20sF and skies will clear overnight.

Snowpack and Avalanche Discussion

There are more similarities than differences in the snowpack. The Bridger Range, entire Madison Range, southern Gallatin Range and Lionhead area have three things in common:

  1. A similar snow structure of weak, faceted, sugary snow at the ground,
  2. A similar snow depth and similar snowfall amount from the last storm (8-10”),
  3. All ranges have recent avalanche activity, and widespread whumpfing and cracking. 

Number three is bulls-eye information the snowpack is unstable and today’s snowfall and wind won’t help. Yesterday a snowmobiler triggered a slide in Buck Ridge (photo), and north of Big Sky a skier triggered an avalanche from 75 feet away (photo). A skier in the Bridger Range triggered a small slide in Bradley’s Meadow (details) and we continued to get pictures of avalanches that ran after Tuesday morning’s storm (photos page). Yesterday, Ian and Dave went to Lionhead in search of avalanches and found a couple of debris piles in poor visibility (video). They did not venture on or under steep terrain for fear of triggering a slide. During times of uncertainty we hedge our bets and travel conservatively, mostly avoiding avalanche terrain. The snowpack will calm down in due time, but for the moment triggering avalanches should be front and center on your mind. Today the avalanche danger is rated CONSIDERABLE on all slopes.

The northern Gallatin Range has weak, sugary snow at the ground. This layer has avalanched in the past, and will again in the future. The range did not get the full brunt of Tuesday morning’s storm and the snowpack was not put under a lot of stress. It is still possible to trigger avalanches since the weak snow is not getting any stronger. Dig and test the stability before venturing into avalanche terrain and back off of slopes if you see red flags of avalanche activity, cracking or collapsing. For today the avalanche danger is rated MODERATE.

Skiers and riders continue to see signs of instability in the mountains around Cooke City. Yesterday, a skier north of town saw a half dozen avalanches and got a few collapses/whumpfs as his party skinned uphill (photos and details). On Tuesday, skiers triggered an avalanche on Henderson Mountain (details). Although there is not a common, widespread weak layer, this recent activity illustrates weakness in the top 3 feet of the snowpack. The only way to know what’s under your feet is to dig. If you don’t dig, then be conservative in your travel and avoid steep slopes. Tracks are not a stand alone assessment of good stability because avalanches regularly pull out slopes that have been ridden and skied. For today, the avalanche danger is rated MODERATE.

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

Upcoming Avalanche Education and Events

See our education calendar for an up to date list of all local classes. Here are a few select upcoming events and opportunities to check out:

Every Saturday in Cooke City, FREE snowpack update and rescue practice at the Round Lake Warming Hut between 10 a.m. and 3 p.m. Poster with More Info.

Friday night and Saturday, January 8 & 9. The Friends of the Avalanche Center are teaching a Companion Rescue Clinic. Learn about avalanche terrain, weather, decision-making and rescue. Get more information and register HERE.

Monday, January 11, 6-7 p.m. The Friends of the Avalanche Center will offer a FREE 1-hr Avalanche Awareness Talk in partnership with Uphill Pursuits. The talk will be given via a live ZOOM session. Please click the link below to join the webinar: Join HERE.

Tuesday, January 19, 6-7 p.m. The Friends of the Avalanche Center will offer a FREE 1-hr Avalanche Awareness Talk in partnership with the University of Montana Western School of Outreach. The talk will be a live, ONLINE event. Join us HERE.  

January 20 & 21 (plus field sessions the following weekends), Avalanche Fundamentals with Field Course. There are separate field sessions tailored for both skiers and splitboarders (Bridger Bowl) and snowmobilers (Buck Ridge). Register here.

The Last Word

Teton County Search and Rescue in Jackson, WY just released a great 2 min video titled Check Yourself, Check Your Friends: Every Single Time. It is a good reminder to be diligent in our preparation.

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