Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, January 26, at 7:30 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.
At 4 a.m. mountain temperatures range from the upper 20s near West Yellowstone and Cooke City to the upper 30s near Bozeman. Winds are blowing 10-20 mph out of the west with ridgetop gust reaching close to 30 mph. Today, a ridge of high pressure will build over the area producing sunny skies and near record warm temperatures. Highs today will reach close to 50 degrees F in the northern mountains and low 40s F in the mountains near West Yellowstone and Cooke City. No new snow is expected over the next 24 hours.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
The primary avalanche problems to watch for today are wind slabs, buried weak layers 1-2 feet deep and wet snow avalanches.
Wind slabs and weak layers are not widespread (video), but both have the potential to produce human triggered avalanches.
Yesterday, a skier in the southern Madison Range observed recent natural avalanche activity on upper elevation, east facing slopes that were wind loaded. A few of these slides steeped down to buried surface hoar and produced crowns 12”+ deep and 50-60’ wide. The Big Sky Ski Patrol also triggered wind slabs 6-12” deep during control work yesterday. On Friday, a snowmobiler triggered a small wind slab in the Lionhead area near West Yellowstone (photo). The slide broke 1-2 feet deep and 50-75’ wide. The wind slab was likely resting over a layer of surface hoar or small grained facets (video). This same layer of buried facets exists in the mountains around Cooke City (video).
Yesterday, we also received a report of skiers in Hyalite Canyon getting unstable results in stability tests on a crust layer about 40 cm's deep. This crust layer formed during a freezing rain event over a week ago and exists in the mountains from Bozeman to West Yellowstone.
This crust layer could become a player today as temperatures reach near record highs. On slopes facing the southern half of the compass, wet loose avalanches will become a growing concern as the day warms up. Pinwheels and point releases are bull’s eye data that the surface snow is losing strength and could produce larger avalanches.
Today, human triggered avalanches are possible on wind loaded slopes and slopes steeper than 35 degrees which have a MODERATE avalanche danger. Less steep, non-wind loaded slopes have a LOW avalanche danger. The wet snow avalanche danger could rise to CONSIDERABLE on southerly aspects by this afternoon.
Doug 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 Forecaster’s Beer Social Fundraiser
The Friends of the Avalanche Center and Montana Ale Works are hosting an Avalanche Forecaster’s Beer Social Fundraiser the evening of January 27th. Get more information and buy tickets here: https://www.ticketriver.com/event/14010
AVALANCHE EDUATION and EVENTS
Take a look at our Education Calendar for all our classes being offered.
Advanced Avalanche Workshop with Field Course, MSU Bozeman, evening lectures 7-9:30 p.m. Wednesday and Thursday, January 28 and 29, with an all-day field session on Saturday. Get more information and register here: https://www.ticketriver.com/event/12445
1-hour Avalanche Awareness, Dillon, UM Western, 6:30 p.m., Tuesday, January 27.
1-hour Avalanche Awareness for Snowmobilers, Livingston, 7 p.m., Tuesday, January 27, Yellowstone Ranger District.
1-hour Avalanche Awareness for Snowmobilers, West Yellowstone, 7 p.m., Saturday, January 31, Holiday Inn.
1-hour Avalanche Awareness for Snowmobilers, Lewistown, 9 a.m. and 11:30 a.m., Saturday, January 31, Fergus Country Trade Center. More info here: http://www.mtavalanche.com/images/15/thunderstruck-13-premiere-and-avalanche-classes