Good Morning. This is Mark Staples with the Gallatin National Forest Avalanche Advisory issued on Friday, December 26, at 7:30 a.m. Today’s advisory is sponsored by the Community Food Co-op in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
Early yesterday many places received another inch or two of new snow before the storm ended. Today will be calm and cold. Temperatures this morning were in the single digits F except near Cooke City where temperatures were a few degrees below zero F. Winds were blowing 5-10 mph gusting 15 mph from the N and W; however, Lionhead near West Yellowstone had north winds averaging 25 mph gusting to 33 mph. Today temperatures should climb into the teens F and maybe break into the 20s F in a few spots. Winds will remain light. The mountains near Bozeman and Big Sky may see flurries. More snow should arrive late Saturday.
Bridger Range Gallatin Range Madison Range
Lionhead area near West Yellowstone
The most dangerous problem today will be avalanches breaking on faceted layers either at the ground or more likely in the middle of the snowpack (photo). We’ve found these layers in the mountains near Bozeman, Big Sky and West Yellowstone. They were breaking easily and propagating fractures in our stability tests prior to yesterday’s snow and wind. Check out a few of our recent videos showing these weak layers. With the stress of new snow and wind deposited snow, there’s a really good chance a skier or rider will trigger an avalanche on one of these layers today.
Under similar conditions, I’ve been surprised many times in the past and wouldn’t trust my life in avalanche terrain. A small avalanche in Beehive Basin just north of Big Sky early this week was a clue from Mother Nature of unstable conditions (photo). Additionally winds from the N and E yesterday loaded many slopes that don’t normally receive wind-blown snow. The Big Sky Ski Patrol reported “there were weird cornices all over the places and snow where there usually isn’t snow.” Some of these wind loaded places in the backcountry may be slopes with some of the weakest, most faceted snow. Today weird wind loading patterns, buried facets and fresh snow will make dangerous avalanche conditions and the avalanche danger is rated CONSIDERABLE.
Cooke City
Although the mountains near Cooke City did not receive as much snow as other areas yesterday, these mountains received nearly 3.5 feet of snow in the last week. The snowpack is generally stronger, but this heavy load of new snow is a red flag by itself. When this much snow falls, we get avalanches (photo). Today will be no exception especially on slopes loaded by recent N and E winds, and the avalanche danger is rated CONSIDERABLE.
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.
AVALANCHE EDUATION and EVENTS
Take a look at our Education Calendar for all our classes being offered.
TOMORROW: Snowmobiler Rescue Course, Cooke City, December 27, 0800-1200. Only four spots left. Register here: https://www.ticketriver.com/event/13721
1-hour Avalanche Awareness for Snowmobilers, West Yellowstone, 7 p.m., Saturday, January 3, Holiday Inn.
Companion Rescue Clinic, Bozeman, Fri eve and Sat field, January 9 and 10, REI. Register for the class here: www.rei.com/stores/bozeman.html
1-hour Avalanche Awareness for Snowmobilers, West Yellowstone, 7 p.m., Saturday, January 10, Holiday Inn.