Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, February 11 at 7:30 a.m. Bridger Bowl Ski Area in partnership with the Friends of the Avalanche Center, sponsor today’s advisory. This advisory does not apply to operating ski areas.
Cooke City picked up an inch of snow last night. Under mostly cloudy skies temperatures are 40F in Bozeman this morning, a whopping 60 degrees warmer than a week ago! Mountain temperatures are in the high teens with ridgetop winds from the west to southwest averaging 20-30 mph and gusting 40-50 mph. Today will have scattered snow showers with 1-3 inches falling as winds continue to blow strong.
Madison Range Southern Gallatin Range
Lionhead area near West Yellowstone Cooke City
Avalanche activity has not waned. Skiers and snowmobilers have released slides 10 out of the last 11 days and we have lots of photo documentation here. Since Saturday there have been nine human triggered slides, many remotely triggered, and a few naturals from Big Sky to West Yellowstone and Cooke City.
- In the northern Madison Range yesterday, skiers remotely triggered a large avalanche from 30 feet away. It ran 18" deep, 200 feet wide and 1,200 feet vertical on the recently buried facets. Two natural avalanches were also seen by the Big Sky Ski Patrol in the backcountry of Lone Peak above tree line too.
- On Sunday, a snowmobiler triggered a slide on Buck Ridge on a south facing slope.
- In the southern Madison Range in Beaver Creek on Sunday, skiers triggered two slides, one remotely, on the layer of facets 1 ½ to 2 feet deep.
- Around Lionhead on Sunday, Mark saw some recent avalanche activity and talked to a rider who triggered a slope that day too (video, photo, photo).
- Yesterday at Lionhead, Karl Birkeland and I were able to remotely trigger a small avalanche from 75 feet away when we postholed downhill and collapsed a layer of surface hoar 18" deep which propagated far and wide (photo, photo).
- Yesterday outside Cooke City skiers triggered small avalanches on the recently buried facets (photo) on relatively low-angled slopes. There was also a third hand report that the Fin, a steep, exposed slope on Republic Mountain, avalanched too.
- On Sunday, from 30 feet away, skiers remotely triggered an avalanche south of Cooke City on a northeast facing ridge. It was 50-100 feet wide and broke on the layer of facets 18” under the surface.
Most of these avalanches have broken on a layer of small facets 18-24 inches deep. The weekend’s snowfall added enough weight to make perfect conditions for triggering avalanches. These same conditions exist today. Remotely triggering slides is scary, even if the slides are small. For today the avalanche danger is rated CONSIDERABLE on any slope steeper than 35 degrees. Slopes less steep have a MODERATE danger.
Bridger Range Northern Gallatin Range
The Bridger Range and northern Gallatin Range also has a layer of facets buried 18-24 inches deep, but they are not as reactive as other mountain ranges. Yesterday Eric toured into Flanders Creek and could not get consistent breaks in his stability tests (photo). Skiers triggered windblown snow on this layer near Frazier Basin on Saturday (photo) which illustrates how this layer could become a widespread problem with additional loading. The first sign of cracking or collapsing would be a warning shot that this layer is unstable underfoot and you should go elsewhere. For today, the avalanche danger is rated MODERATE on all slopes.
I will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984.
KING AND QUEEN OF THE RIDGE
Saturday, February 15th is the 12th Annual King and Queen of the Ridge Hike/Ski-a-thon fundraiser to support avalanche education in southwest Montana. Collect pledges for one, two or the most ridge hikes you can do in the five hours of competition. 100% of the proceeds go to the Friends of Gallatin National Forest Avalanche Center. Kids and families are encouraged to hike too! Hike as an Individual or Team. Make a Pledge. Sign Up. More Info.
EVENTS/EDUCATION
February 12, BOZEMAN: Wednesday, 6:30-7:30 p.m., MSU Procrastinator Theater, Sidecountry IS Backcountry lecture.
February 20, BOZEMAN: Thursday, 6:30-8:00 p.m., REI, Women’s Specific Avalanche Awareness lecture. Pre-registration is required: www.rei.com/stores/bozeman.html
February 22, BIG SKY: Saturday, 10 a.m. – 2 p.m., Beehive Basin Trailhead, Companion Rescue Clinic. Space is limited and pre-registration is required. https://ticketriver.com/event/9964
February 22, WEST YELLOWSTONE: Saturday, 7:00-8:00 p.m., Holiday Inn, 1 –hour Avalanche Awareness for Snowmobilers lecture.
More information our complete calendar of events can be found HERE.