GNFAC Avalanche Forecast for Sat Mar 22, 2025
This is Dave Zinn with the avalanche forecast on Saturday, March 22nd, at 7:00 a.m., sponsored by Polaris and Montana State Parks. This forecast does not apply to operating ski areas.
24 Hour Snow Totals:
- 4-5” around Cooke City, Island Park, and West Yellowstone (including the S. Gallatin and S. Madison Ranges).
- Trace around Bozeman and Big Sky.
This morning, temperatures are in the teens and 20s F with 15-35 mph winds from the southwest and west. Snow is falling across much of the forecast area, with higher precipitation rates farther south around Island Park, West Yellowstone and Cooke City.
Today, high temperatures will be in the 20s to low 30s F, with strong winds this morning blowing 20-40 mph from the west and southwest. By tomorrow morning, the mountains around Cooke City, Island Park and West Yellowstone will receive 3-5 inches of new snow, with 1-3 inches near Bozeman and Big Sky.
In the mountains around Cooke City, Island Park, and West Yellowstone, including the Southern Madison and Southern Gallatin Ranges, strong winds will drift recent snow, loading slopes where triggering wind slab avalanches that break 1-2 feet deep are likely. Continued snowfall and increasing winds will exacerbate this instability today. On Thursday, snowmobilers in Island Park reported that drifted snow and cornices cracked and collapsed easily on test slopes (observation). Avoid steep terrain where active drifting, cornices and shooting cracks indicate instability. Select slopes sheltered from the wind—often found at middle and low elevations where the trees block the wind—for safer avalanche conditions.
In the Lionhead area, and Southern Madison and Southern Gallatin Ranges, weak layers buried in late January continue to result in infrequent persistent slab avalanches. The most recent slide in the Taylor Fork occurred Wednesday and broke 2-4 feet deep (details). These layers have not resulted in avalanches in the Centennial Range, but snowmobilers assessing for instability noted a weak layer buried two feet deep below a melt-freeze crust that broke and propagated in unstable test results. Manage the problem of avalanches failing on persistent weak layers by selecting less consequential terrain (smaller slopes with fewer terrain traps) and following safe travel practices (beacon, shovel, probe, and traveling one at a time on steep slopes). Testing for instability can reduce, but will not eliminate, the chances of a surprise.
The danger is CONSIDERABLE on wind-loaded slopes and MODERATE on all others.
Windy conditions in the mountains around Bozeman and Big Sky will cause the limited snow available for transport to drift into slabs that could avalanche on steep slopes. The terrain immediately below cornices and on upper-elevation slopes loaded by west and southwest winds is the most likely area to trigger a wind slab avalanche, breaking 6 inches to a couple of feet deep. On Wednesday, a skier was caught and carried 100 feet down a steep slope south of Bridger Bowl, serving as a poignant reminder of the power of a relatively small slide (details and video). Yesterday in Beehive Basin, Ian recommended identifying and avoiding wind-loaded slopes and digging down a couple of feet to test for instability, reducing the chances for surprises if you are considering travel in steeper terrain (observation and video). Shooting cracks and recent avalanche activity are the most precise indicators of instability.
Seek out terrain sheltered from the wind where avalanche conditions are generally safe, and slides are unlikely. The danger is MODERATE on wind-loaded slopes and LOW on all others.