Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Monday, January 29th at 6:45 a.m. Today’s advisory is sponsored by Highline Partners and Gallatin County Search and Rescue. This advisory does not apply to operating ski areas.
Since yesterday the mountains near Cooke City got 3” of snow, near West Yellowstone got 1-2”, and elsewhere got a trace to an inch. Temperatures this morning are mid-20s F and will reach low 30s F today. Wind is westerly at 15-25 mph with gusts of 30-50 mph. No new snow is expected through tonight, then another round of snow begins tomorrow morning.
Since Friday the mountains near Cooke City got 1.5 to 2 feet of snow equal to 1.5” of snow water equivalent (SWE). West to southwest wind drifted this light powder into 1-3’ deep soft slabs that are easy to trigger. Yesterday, skiers near Cooke City triggered small soft slab avalanches from low angle terrain 10-20 feet away (photo, photo). These types of slides are likely today. Be cautious of wind loaded slopes and avoid all steep slopes if you see collapsing or cracking of the snow surface. Stay back from the edge of cornices along ridgelines, and avoid large pillows of snow below.
Avalanches breaking deeper than recent snow are difficult to trigger, but are possible and can be large (photo). These are more likely where the snowpack depth is highly variable or relatively shallow. Dig and test stability of a layer of facets 1-2’ above the ground before riding steep slopes.
Snow and wind over the weekend formed slabs that are easy to trigger. The avalanche danger is CONSIDERABLE on wind loaded slopes and MODERATE on all other slopes.
The mountains near Bozeman, Big Sky and West Yellowstone got 6-10” of new snow over the weekend that was drifted into wind slabs 1-2’ thick. These wind slabs are possible to trigger near ridgelines and along the edges of cliffs and gullies. Be cautious of wind loaded slopes, stay back from the edge of ridgelines to avoid large cornices, and avoid steep slopes directly below.
Doug was in Cabin Creek in the southern Madison Range yesterday and found the weak layer of facets 3-5’ deep to be relatively strong (video). Large avalanches on this layer are difficult to trigger, but possible. This weak layer is particularly dangerous and unstable in the Lionhead area near West Yellowstone (video, photo), and on slopes with a relatively shallow snow depth. Carefully evaluate the snowpack before riding any steep slope, and never expose more than one person at a time to steep slopes or terrain below. Avalanche danger today is MODERATE.
If you get out and have any avalanche or snowpack observations to share, drop a line via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
King and Queen of the Ridge
King and Queen of the Ridge, Saturday, February 3rd. A Hike and Ski/Ride-a-Thon fundraising event to support the Friends of the Gallatin National Forest Avalanche Center. Sign up and start collecting pledges HERE.
Upcoming Avalanche Education and Events
BOZEMAN
Feb. 6th, Sidecountry specific avalanche awareness for family and friends. 6-8 p.m. @ Beall Park
Feb. 7th, Woman’s specific avalanche awareness, 6-7:30 p.m. @ REI in Bozeman
Feb. 7th, Avalanche awareness, 6-7:00 p.m. @ Roskie Hall MSU
Feb. 9 and 10, Companion Rescue Clinic, Info and Register
March 2nd, Avalanche Awareness, 6-7:00 p.m. Bozeman Split Fest
March 7th, Avalanche Awareness, 6-7:30 p.m. @ REI
PHILLIPSBURG
Feb. 8th, Avalanche Awareness, 6:30-8:30 p.m. @ the new Fire Hall
DILLON
Feb. 24th and 25th, Snowmobile intro to avalanches w/ field course. More info: https://msuextension.org/conference/.
WEST YELLOWSTONE
Feb. 3rd, Avalanche Awareness, 7-8 p.m. at West Yellowstone Holiday Inn Conference Center
Feb. 10th, Avalanche Awareness, 7-8 p.m. at West Yellowstone Holiday Inn Conference Center
COOKE CITY
Every Friday and Saturday, Current Conditions Update and Avalanche Rescue, Friday 6:30-7:30 p.m. at The Soda Butte Lodge in February. Saturday anytime between 10-2 @ Round Lake.
Dashboard Talks, Episode 4: Doug Chabot and Eric Knoff talk about the questions they ask themselves about avalanches when they are in the backcountry regarding terrain and snowpack.