Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 5, at 7:30 a.m. Today’s advisory is sponsored Cooke City Super 8/Bearclaw Bob’s and Spark R&D. This advisory does not apply to operating ski areas.
A moist southwest flow dropped 1-2 inches of new snow around Big Sky, West Yellowstone and Cooke City. This morning under mostly cloudy skies, temperatures are in the low 20s with south to southwest winds blowing 10-20 mph. Today will be mostly cloudy with scattered flurries dropping a trace to 1 inch by morning with the mountains around Bozeman getting missed. Winds will remain light and temperatures will warm to near freezing.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
Throughout southwest Montana our snow structure is poor. We have denser slabs of snow sitting on top of weaker, sugary facets. This snowpit profile from Lionhead illustrates this well. Just imagine stacking children’s building blocks with the thickest, widest pieces balancing on the very smallest ones: it might tip over. And so might our snowpack. As days pass without significant snowfall, triggering an avalanche becomes less likely but still possible. Large facets of depth hoar remain weak and I am traveling in avalanche terrain cautiously.
Over the last few days light winds have been blowing out of the west to southwest, but in the northern ranges winds were occasionally stronger which loaded slopes near the ridgetops. A skier reported an avalanche on the northeast face of Mt. Blackmore up Hyalite that occurred over the weekend. It was likely triggered by wind-loading. Alex was up there yesterday and got poor stability test scores on the depth hoar, the same scores as a week ago. Yesterday, the Big Sky Ski Patrol was able to ski cut fresh wind slabs up to 18 inches thick. Furthermore, the top 4-6 inches of our snowpack has faceted in response to the cold and clear weather. Once this gets buried by fresh snow or wind-loading we’ll have another weak layer to deal with, which Eric and I documented in this video from Lionhead.
The last human triggered avalanche was only four days ago in Cooke City (video). The snowpack here is very similar to the rest of our forecast area, so what goes on there is relevant to all backcountry travelers. Warnings of instability include these avalanches in Cooke City (photo), slides on Yellow Mountain near Big Sky (photo) and Mount Blackmore, along with cracking and collapsing in the southern Gallatin Range. The danger level is rated MODERATE on all slopes throughout our advisory area since avalanches are still possible.
I will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations to share, drop us a line at mtavalanche@gmail.com or leave a message at 587-6984.
EVENTS and AVALANCHE EDUCATION
A complete calendar of classes can be found HERE.
EVENT in Bozeman: January 19, 5:30-7 p.m. and 7:30-9 p.m., Avi Center Beer Social at Montana Ale Works. Fundraiser for the Friends of the Avalanche Center, $35. Tickets here: https://www.ticketriver.com/event/18542
Bozeman: January 6, Women’s Avalanche Awareness and Beacon 101, Beall Park, 6-8 p.m.
January 8 and 9, Companion Rescue Clinic, REI, Fri 6-8p.m., Sat 10a.m.-2p.m.
January 13, 1hr Avalanche Awareness, REI, 6-7:30 p.m.
Four Corners: January 13, 1hr Avalanche Awareness for Snowmobilers, GVSA Groomer Building, 7-8 p.m.
West Yellowstone: January 9, 23, and 30, 1hr Avalanche Awareness, West Yellowstone Holliday Inn, 7-8:30 p.m.
Livingston: January 14, 1hr Avalanche Awareness, Neptune’s Brewery, 6-7:30 p.m.
Cooke City: January 16, 1hr Avalanche Awareness, Visitor’s Center, 6-7:30 p.m.
January 30, Companion Rescue for Snowmobilers, https://www.ticketriver.com/event/18078
Dillon: January 19, 1hr Avalanche Awareness, UM Western Library, 6:30-8 p.m.
January 23 and 24, Intro to Avalanches w/ Field Course, https://www.ticketriver.com/event/18441
ASMSU Intro to Avalanches w/ Field Course
January 20, 21 and 23 or 24: https://www.ticketriver.com/event/16861
The workshops will be held on Wednesday and Thursday evenings, with a field course on either Saturday or Sunday. Different topics will be presented each evening. Topics include: avalanche terrain recognition, the effect weather has on avalanche hazard, the development of the mountain snowpack, decision making skills, and basic search and rescue procedures.
Advanced Avalanche Workshop w/ Field Course
January 27, 28, and 30: https://www.ticketriver.com/event/16862
Course content includes: snowpack metamorphism, the mechanics of avalanche failure and fracture, and decision-making. Different topics are covered each evening session. The field session includes snowpack analysis and avalanche rescue scenarios.