Good morning. This is Alex Marienthal with early season weather and avalanche information for the Gallatin National Forest Avalanche Center on Saturday, October 21st at 6:45 a.m. This bulletin is sponsored by The Friends of the Avalanche Center and Grizzly Outfitters, the title sponsor of Powder Blast on October 27th.
At 4:30 this morning temperatures are teens to low 20s F. There is 5” of new snow near Bozeman and Big Sky with 2” near West Yellowstone and Cooke City. Wind is out of the west at 15-20 mph with gusts of 30-40 mph.
Today will be partly cloudy. Temperatures through the weekend will be in the 30s F. Wind will be west to southwest at 15-25 mph today, and will increase to 30-40 mph Sunday morning. Snow through the day on Sunday will drop 3-6” near Bozeman, Big Sky and West Yellowstone, and 7-12” near Cooke City.
Wind and new snow make it possible to trigger avalanches this weekend. Westerly wind will drift snow into thick slabs that could be triggered by skiers, hunters, or ice climbers. These fresh wind slabs should be completely avoided in steep terrain. Terrain traps such as rocks trees and gullies increase the consequences of even the smallest slide, and are more prevalent right now due to thin snow cover. Avalanches can pile debris deep in gullies and confined terrain, and slides are deadly above cliffs like on the approach to climbs on the Sphinx.
Ice climbers should completely avoid steep, high consequence terrain if it’s loaded with fresh snow, and turn around at the first sign of instability such as cracking of fresh drifts. A small, 15’ wide avalanche killed two climbers on the Sphinx in October 2004.
Hunters often travel solo and don’t carry avalanche rescue gear, so should completely avoid steep, snow covered avalanche terrain. Avoid deep, dense or hard drifts of snow near ridgelines and on the steep sides of gullies. If necessary, cross these features one at a time, at the top versus mid-slope, and watch each other from a safe area.
Skiers need to carry rescue gear as they normally would in the middle of winter (Beacon, Shovel, and Probe). Put fresh batteries in your beacon and practice using it, check your probe and shovel for damage, and check your partners’ gear before you leave the trailhead. Slopes with the most snow are the most attractive to ride as they are smooth and rock free, but are also more likely to have fresh drifts that could avalanche. Assess the snowpack and avoid steep terrain if you see collapsing or cracking of the snow.
Before this weekend’s snow there was 1-3 feet of snow on shady, high elevation slopes while sunny and wind scoured slopes had little to no snow (photo, photo, photo, snowpit). Short days and less direct sunshine mean this snow is likely here to stay. These layers are the foundation of our snowpack. Now is the time to start observing their distribution, and their behavior during and between storms. 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).
We will update daily weather information on our website after storms, and issue early season bulletins as conditions warrant.
Powder Blast Fund-raiser
27 October, 6:30 p.m. at the Emerson Cultural Center. Tickets and Info
Grizzly Outfitters of Big Sky is title sponsor of this year's 19th Annual Powder Blast. Mystery Ranch, World Boards, Community Food Co-op, and Spark R&D are key sponsors along with Alpine Orthopedics, Stronghold Fabrication, Highline Partners, and Marcie Hahn-Knoff Real Estate. Javaman, Edward Jones and Buck Products are other long-time PB supporters.
Your $30 donation gets you an unforgettable evening at the Emerson Cultural Center.
Beer from Katabatic Brewing Company; Wine from Montana Ale Works; Dinner by Bountiful Table; Music by DJ Missy O'Malley
And the best silent auction of outdoor gear in the valley!
Events and Education Calendar - Stay tuned as we will update our calendar with more classes over the next few months.
1 November, Avalanche Awareness, 6-7:30 p.m. at REI Bozeman
6 December, Avalanche Awareness, 6-7:30 p.m. at REI Bozeman
7 December, Avalanche Awareness and Beacon Practice, 6-8 p.m. at Beall Park, Bozeman
Nov. 29, 30 and Dec. 2, 3 or 9, Introduction to Avalanches w/ Field Day, Info and Register Here
Jan. 12 and 13, Companion Rescue Clinic, Info and Register
Jan. 17, 18 and 20 or 21, Introduction to Avalanches w/ Field Day, Info and Register Here
Jan. 24, 25 and 27, Advanced Avalanche Workshop w. Field Day, Info and Register Here
Feb. 9 and 10, Companion Rescue Clinic, Info and Register
