Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast issued on Sunday, March 3rd at 7:00 a.m. Today’s forecast is in memory of Ben Richards. Ben was killed in an avalanche twelve years ago today. He will be forever missed and remembered. This advisory does not apply to operating ski areas.
Since yesterday morning no snow fell in the mountains. This morning temperatures are teens below zero F in the mountains near Bozeman, and single digits above and below zero F elsewhere. Wind is 0-10 mph out of the west-northwest, and in the Bridger Range wind is east-southeast. Today temperatures will reach single digits to low teens above zero F, and wind will be northerly at 0-10 mph. The next chance for snow is Tuesday night.
Last week the mountains in the southern half of our advisory area and near Cooke City received 4-6 feet of heavy snow (4-6” of snow water equivalent), and an avalanche warning expired on Friday. Yesterday natural avalanches were reported in the southern Madison Range (photo) and mountains near Cooke City (details). A snowmobiler triggered a deep avalanche on a small slope near Sage Peak in the southern Madison Range and luckily was not caught (photo and details). On Friday Eric and I rode in Taylor Fork and saw no signs of instability (video), but slides yesterday are bullseye data that some slopes are unstable.
The last couple days with minimal snow and light wind allowed the snowpack to adjust to the recent heavy snow. Avalanches are becoming less likely, but are still possible today. Wind loaded slopes are the most dangerous, and avalanches of recent snow can break up to 2-4’ deep on any slope steeper than 35 degrees. Watch for cracking of the snow surface or avalanches on small test slopes as signs to avoid bigger steep terrain. Avalanches could break deeper and wider on weak snow at the base of the snowpack (video). Today large avalanches are possible to trigger and avalanche danger is MODERATE.
Yesterday we received reports of natural and human triggered avalanches in Hyalite, the Bridger Range and near Big Sky (Activity Log). A large natural avalanche occurred on the west side of Saddle Peak in the Bridger Range (details and photos), which was not far from a fatal avalanche that happened Tuesday (report). The Yellowstone Club ski patrol triggered an avalanche with explosives, which broke four feet deep on weak snow at the ground (details and photos). They also reported a snowmobile triggered slide near Cedar Mountain (details and photo).
Wind loaded slopes are the main concern in the mountains near Bozeman and Big Sky. Soft slabs 1-2’ thick are possible to trigger. Watch for cracking of the snow surface as a sign these fresh drifts are unstable. A less likely, but larger consequence avalanche can be triggered on weak snow deep in the snowpack. Yesterday we went to Beehive Basin to look for this weak snow that was likely responsible for a large natural avalanche on Friday (video, photo). The best way to avoid this type of slide is to avoid heavily wind loaded slopes and slopes where the snowpack is relatively shallow (less than 5 feet).
Today, human triggered avalanches are possible and the avalanche danger is rated MODERATE. Carefully assess the snowpack and terrain before riding steep slopes.
If you get out and have any avalanche or snowpack observations to share, contact us via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
BOZEMAN
Today, Bozeman Split Fest, More info at www.bozemansplitfest.com.
March 6, 1-hr Avalanche Awareness, 6-7 p.m. at REI Bozeman.
March 6, Drinks for a Purpose, 5-8 p.m. at Bozeman Spirits Distillery, More info.
COOKE CITY
Every Friday and Saturday, Rescue Training and Snowpack Update. Friday 6:30-7:30 p.m. at the Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.
The accident report for the avalanche fatality in the Bridger Range on February 26th is complete. You can view the report here.