GNFAC Avalanche Forecast for Tue Jan 26, 2021

Not the Current Forecast

Good Morning. This is Dave Zinn with the Gallatin National Forest Avalanche Forecast on Tuesday, January 26th at 7:00 a.m. Today's forecast is sponsored by Stronghold Fabrication and Cooke City Motorsports. This forecast does not apply to operating ski areas.

Mountain Weather

Mountain temperatures are in the single digits F with 5-15 mph wind shifting from the east to southwest and there is no new snow. Today, temperatures will reach the teens F with wind from the southeast to southwest blowing 5-15 mph. Light snow tonight will provide an inch to West Yellowstone and Cooke City by morning. Continuing snow tomorrow will favor the mountains around West Yellowstone before filling in to the north later in the week.

Snowpack and Avalanche Discussion

The mountains from the Lionhead Range through the Bridger Range received 1-3" of snow in the previous seven days and nothing in the last four. The lack of new snow provides the weak snowpack time to adjust and avalanches are becoming less likely. On Sunday, a snowmobiler triggered a wind-loaded slope in the Taylor Fork that piled debris 8 feet deep (photo). Yesterday, we did not see any other recent activity in the area, but we triggered a collapse and found a reactive layer of surface hoar buried 6-18" under the snow (video). Alex found similar conditions at Bacon Rind (video). The weak depth hoar near the snowpack's base across all areas remains the most concerning weak layer. In the last week, we have reported avalanches, loud "whumphs" and unstable test results in the Madison, Gallatin, Lionhead and Bridger Ranges (weather and avalanche log, Lionhead video, Buck Ridge video). In the last two days and for the first time in a month, depth hoar in two of my snowpits did not propagate failure with extended column tests. This is a good sign, but keep the big picture in mind remembering that trust for this deeply buried sugary snow will be hard-earned.

Plan your route carefully and assess the snowpack thoroughly if you are considering entering avalanche terrain. Finding any sign of instability is a good reason to turn around and stick to low-angle terrain. Large, human-triggered avalanches remain possible and the danger is rated MODERATE.

Snowmobilers triggered several avalanches north of Cooke City three to four days ago on a layer of weak snow buried 12-18" deep. Yesterday, skiers recently witness a spiderweb of shooting cracks breaking on the same layer (photo). Despite these events, stability is showing signs of improving. Currently, Doug is documenting these and other avalanches in the area (check out the Huckleberry photo, Miller Ridge photo, Sheep Mountain photo). He found the suspect weak layer buried and it is adjusting to the weight on top (photo). A second weak layer of sugary snow is buried 2-3' deep on some slopes. This deeper layer is more prevalent in the thinner snowpacks around Cooke City and skiers recently triggered large collapses on this layer.

While tracks don't equal stability, riders are climbing steep slopes and are generally not triggering avalanches. A rider or skier can get unlucky and hit the "sweet spot" but the snowpack is less sensitive. Human-triggered avalanches remain possible and the 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.

Tuesday, January 26, 6-7 p.m. Free 1-hour Avalanche Awareness in partnership with Hi-Line Climbing Center and Stronghold Fabrication. Join on Zoom here.

February 5 and 6, Women's Companion Rescue Clinic with SheJumps. Registration HERE.

February 19 and 20, Companion Rescue Clinic. Registration HERE

February 26 and 27, Women's Companion Rescue Clinic with SheJumps. Registration HERE.

King and Queen Fund-raiser

February 6th and 7th, Saturday and Sunday, at Bridger Bowl. Due to the pandemic it is a GS race this year. Prizes will be awarded for the fastest race results AND separate prizes for folks who raise the most money over $500. No racing is necessary to compete for the fundraising prizes. Info is HERE.