Good morning. This is Dave Zinn with the Gallatin National Forest Avalanche Forecast on Friday, November 25th at 7:00 a.m. This information is sponsored by Mystery Ranch and the Avalanche Alliance. This forecast does not apply to operating ski areas.
*Note: Bridger Bowl Ski Area is closed and there is 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
This morning, mountain temperatures are 30 to 40 degrees F with 10-15 mph winds from the west to northwest. Lingering flurries yesterday morning brought 1-2” of new snow to the Taylor Fork and Cooke City areas, with nothing for the remainder of the advisory area. Today, high temperatures will be in the 30s to 40s F under mostly sunny skies. Winds will blow 15-20 mph from the southwest and increase late in the day. Snow and cooler temperatures will return on Saturday.
A snowstorm Tuesday night into Wednesday brought 8-11” of snow to the mountains near Cooke City, Big Sky and Bozeman, and 3-5” to the mountains around West Yellowstone. The new snow fell onto a weak surface of facets, and winds from the west to northwest transported the new snow into drifts where avalanches are possible. Yesterday, a skier was caught and carried in by a slide that broke 15’ wide and 8” deep in a drift formed on a steep slope in Bridger Gully. Thankfully, he was not buried or injured (details). Another group in the Bridger Range saw a small avalanche that was likely human-triggered near the Nose (details and photos). Skiers in the Bridger Range noted strong mid-elevation winds and watched as the snow was transported into slabs (Observation and Photos 1, 2, 3). While the observations we received are Bridger Bowl-centric, the story applies across the advisory area.
Today, the primary concern is triggering avalanches in recent drifts of snow. Avoid steep, wind-loaded terrain and retreat if you observe recent avalanches or cracks shooting from your sled or feet.
A secondary concern is triggering wet-loose snow avalanches as temperatures climb above freezing under mostly sunny skies. Yesterday, a skier near Beehive Peak intentionally triggered a loose snow avalanche that grew large enough to bury or injure a skier where he noticed pinwheels and warming snow near rocks (photo and details). Avoid slopes where the snow surface is getting wet or you see pin-wheels of snow.
Today, human-triggered avalanches are possible. Identify and avoid terrain features of concern by looking for signs of recent wind-loading and instability, like avalanches or shooting cracks. As a final step, dig a pit to test for instability. The danger is MODERATE.
Recent snow fell onto a weak surface of faceted snow and winds from the west to northwest transported snow into drifts where avalanches are possible. Avoid drifts of snow in steep terrain and retreat if you observe recent avalanches, or cracks shooting from your sled or feet. A rider earlier in the week noted cracks in the snow near the track of their sled on Reas Peak, an indicator of instability (photo).
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.