Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Monday, January 15th at 7:00 a.m. Today’s advisory is sponsored by Grizzly Outfitters in partnership with the Friends of the Avalanche Center. This advisory does not apply to operating ski areas.
The mountains got a trace of snow this morning and temperatures are in the teens to low 20s F. Wind overnight was northwest at 10-20 mph, and 25-30 mph near Cooke City. Today, wind is north to east at 5-15 mph with temperatures reaching high 20s F. Skies will clear this afternoon and no snow is expected over the next 24 hours.
The Lionhead area near West Yellowstone has dangerous avalanche conditions. Large avalanches are easy to trigger on steep slopes, and from adjacent less steep terrain. Avoid steep slopes and terrain below. Two to three feet of heavy snow is sitting over weak, sugary facets. The weight of a rider or skier can easily collapse the heavy slab of snow across entire slopes (video). Yesterday, two large snowmobile triggered avalanches were observed (photo), and on Saturday snowmobilers triggered a large slide from low on the slope (photo). No one was caught in these slides. Last Wednesday, an avalanche claimed the life of a rider in the nearby Centennial Range where there is a similarly unstable snowpack. Today, dangerous avalanche condition exist and the avalanche danger is CONSIDERABLE.
The mountains near Cooke City got 2-3 feet of snow equal to 2.7” of snow water equivalent (SWE) Wednesday through Saturday. This load produced large natural avalanches (photo), mostly on wind loaded slopes (photo, photo, photo). Similar avalanches are possible to trigger today. Strong northwest wind last night created smaller, fresh wind slabs that are easy to trigger. On non-wind loaded slopes, larger avalanches are possible on weak layers buried 3-4’ deep (photo). These are more likely where the snowpack is shallower, 3-5’ deep. Today, avalanche danger is CONSIDERABLE on wind loaded slopes and MODERATE on non-wind loaded slopes.
Last week the mountains near Big Sky and Bozeman got 2- 3 feet of snow. In the Bridger Range this snow equaled 3.7” SWE, and in the Gallatin and Madison Ranges 1.5-2.5” of SWE. On Saturday, large slabs of new snow avalanched naturally south of Bridger Bowl (photo). Yesterday, we found these instabilities and anticipate they will quickly heal (video). Over the weekend, skiers and climbers in Hyalite observed natural avalanches, and avoided wind loaded slopes (photo, video). Today, similar wind slabs are possible to trigger.
Avalanches on weak facets 2-4’ deep are possible, but less likely without new snow. This instability is found where the snowpack is relatively shallow, 3-5’ deep. On Friday, skiers in the northern Madison Range remotely triggered a large avalanche on this layer (photo). Be cautious of lower elevation terrain and slopes with highly variable snow depth. Today, the avalanche danger is MODERATE on all slopes.
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
TONIGHT!!!, Avalanche Awareness, 6-7 p.m. at Yellowstone Motorsports
Jan. 17, 18 and 20 or 21, Introduction to Avalanches w/ Field Day, Info and Register Here
Jan. 22, MAP Brewing Pint Night, 4-8 p.m. MAP donates 50 cents of every pint sold to the Friends of the Avalanche Center.
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
WEST YELLOWSTONE
Jan. 20, Avalanche Awareness, 7-8 p.m. at West Yellowstone Holiday Inn Conference Center
Dillon
Jan. 16, Avalanche Awareness, 6:30-8 p.m. at U.M. Western Library
COOKE CITY
Every Friday and Saturday, Current Conditions Update and Avalanche Rescue, Friday 6:30-7:30 p.m. at The Antler's Lodge in January. Saturday anytime between 10-2 @ Round Lake.
Watch the new Dashboard Talks, Episode 3: Down in a Hole. You should dig snowpits and perform stability tests, but how many is enough? Well that depends... Doug and Eric discuss the relationship between your objectives and pit digging.