Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Sunday, November 27th at 7:00 a.m. This information is sponsored by Gallatin County Sheriff Search and Rescue and Spark R&D. This forecast does not apply to operating ski areas.
*Note: Bridger Bowl Ski Area is closed and there are no avalanche control or ski patrol services. Backcountry conditions exist. Please don’t ski over hoses and power cords, stay off chairlifts, and give snowcats and snowmobiles plenty of room.
Yesterday morning the mountains near Bozeman and Big Sky received 3-4” of snow and 1-2” fell elsewhere. Overnight, west-southwest wind increased to 15-25 mph with gusts of 30-40 mph. Temperatures are low teens to low 20s F this morning. Today, temperatures will reach high teens to 20s F, and wind will be westerly at 25-40 mph with a few snow showers. More snow is expected tonight with 1-2” near West Yellowstone, 3-6” near Bozeman and Big Sky, and 6-9” near Cooke City by tomorrow morning.
Strong west-southwest wind is drifting new snow into dense slabs which are the main avalanche concern today. These fresh drifts can avalanche under the weight of a person, could be large enough to bury someone, and can easily carry a person down a steep slope. If you travel in steep terrain, assess the stability of new snow and fresh drifts, and avoid drifts of any size on slopes that end in cliffs, thick trees or confined gullies.
Over the last week, new snow followed by moderate to strong wind created drifts that were triggered by skiers (Skier caught and carried, skier triggered wind slab), and on high northerly slopes a few avalanches broke on weak layers near the bottom of the snowpack (Hyalite Peak avalanche, natural avalanche on deeper weak layers at Big Sky). Although less likely, avalanches could break below the 4-10” of snow that fell earlier this week. If you plan to ski or ride on steep slopes, dig down a couple feet to assess older weak layers.
Today, human-triggered avalanches are possible and the avalanche danger is MODERATE.
Near Island Park, strong wind will drift 2-4” of new snow into dense slabs. If you travel in steep terrain, assess the stability of new snow and fresh drifts, and avoid drifts of any size on slopes that end in cliffs, thick trees or confined gullies. If you plan to ski or ride on steep slopes, dig down a couple feet to assess older weak layers.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Tuesday, November 29, 6 p.m. Sidecountry Avalanche Awareness for Families (and Friends) at Story Mill Park. Free.
Tuesday, December 6, 9 a.m. - 3:00 p.m. West Yellowstone Avalanche Fundamentals w/ Snowmobile Field Session. Pre-register HERE.
Tuesday, December 13, 6 p.m. Avalanche Awareness + Beacons at Story Mill Park. Free.
The Friends of the Avalanche Center are hosting the Powder Blast Fundraiser. Your donations support free and low-cost avalanche education, beacon checkers at trailheads, beacon parks, weather stations, and GNFAC programs! The Friends of GNFAC launched an online GoFundMe campaign. Please consider a donation, and we look forward to having an in-person event again in the future.