Good morning. This is Ian Hoyer with the Gallatin National Forest Avalanche Forecast on Friday, January 13th at 7:00 a.m. This information is sponsored by Blitz Motorsports and Yamaha and Montana State Parks. This forecast does not apply to operating ski areas.
There is no new snow to report. Winds are 10-20 mph out of the southwest to west, gusting to 40 mph. Temperatures rose slightly overnight and are in the 20s and 30s F this morning. Temperatures will continue to rise into the 30s and maybe even hit 40 F. Skies will be mostly sunny with south and southwest winds at 10-20 mph. A light dusting of snow is possible tonight.
Over the last week around a foot of snow fell in the mountains near West Yellowstone and Cooke City. There is a weak layer of surface hoar beneath the new snow on most slopes (Lionhead, Taylor Fork, Cooke City videos). We haven’t seen avalanches on this layer yet, but there have been whumpfs and poor test scores (observation). The reason we’ve been focusing on this layer so much, even without avalanches breaking on it yet, is that surface hoar is notorious for catching even experienced professionals off guard. Avalanches on it can be triggered from the flats and break much wider or further above you than you might expect. Dig down to test this layer before riding steep slopes.
The weak layers at the ground are our other major concern. Triggering a slide on these layers would take finding just the wrong weak spot, but the resulting slide could be huge. Identify likely shallow areas (the most likely triggering spots) and steer clear of them. Be on high alert if the track of your snowmobile is digging to the ground or you’re punching through when you step out of your skis, as this means you’ve found a thin, weak area. For today, large avalanches are possible and the danger is rated MODERATE.
There has been less new snow around Bozeman and Big Sky, but our concerns are similar. Without much of a fresh load, avalanches are getting more difficult to trigger with each passing day. The weak snow near the ground is still weak and thin layers of faceted snow mid-pack could also break (Bridgers video). Last weekend, there were a number of natural and human triggered avalanches (avalanche activity list). Similar slides could be triggered today. Dig and test for instability, but also just keep your objectives appropriate for a mid-winter snowpack with several known weak layers that have a recent history of avalanching.
Yesterday, in Hyalite skiers triggered a thin wind slab that was only a couple inches deep, but propagated 40 ft wide (details). Stay alert because even a thin avalanche in a little bit of wind drifted snow could be dangerous in high consequence terrain. The avalanche danger is rated MODERATE today.
Please share avalanche, snowpack or weather observations via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
In Island Park, there is a weak layer of surface hoar beneath the new snow on most slopes. Avalanches on it can be triggered from the flats and break much wider or further above you than you might expect. Dig down to test this layer before riding steep slopes. Triggering a slide on weak layers near the ground would take finding just the wrong weak spot, but the resulting slide could be huge.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Every Saturday, 10 a.m. - 2:00 p.m. Avalanche Rescue Training, drop in for any amount of time. Round Lake Warming Hut, Cooke City. Free.
Loss in the Outdoors, is a support group for those who have been affected by grief and loss related to outdoor pursuits. Check out the link for more information.
KING AND QUEEN OF THE RIDGE, FEBRUARY 4TH
Do you like to hike? Do you like to ski? Then the King & Queen of the Ridge is for you. Hike, ski and raise money for the Friends of the Avalanche Center in their 2nd biggest fundraiser of the year. Join the effort to promote and support avalanche safety and awareness! Fundraising prizes for the top 5 individuals who raise over $500. No racing is necessary to compete for the fundraising prizes. Info is HERE. Race participants for the February 4th event must register separately with Bridger Bowl HERE.
Last Saturday in Colorado, two snowmobilers were caught, buried, and killed in a large avalanche on the east face of Mount Epworth, about 6 miles east of Winter Park. Grand County Sheriff's Deputies and search and rescue were unable to locate the second rider before dark, but found the second rider deceased the next day. (Preliminary report).