Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Advisory issued on Monday, March 19th at 6:45 a.m. Today’s advisory is sponsored by Bridger Bowl and Montana State Parks. This advisory does not apply to operating ski areas.
Last night the mountains near Bozeman and Big Sky got a trace to 1” of snow, and near West Yellowstone and Cooke City got zero. Temperatures this morning are teens F and wind is west-northwest at 5-15 mph. Today will be partly cloudy with temperatures in the 20s to low 30s F and west wind at 5-15 mph. Light snow showers through tonight will drop 1-2” of snow in the mountains by morning.
Snow that fell at the end of last week created unstable slabs that broke naturally and were easily triggered by skiers (photo, photo, video). Near Bozeman and Big Sky these avalanches broke on lower density snow below a thick slab, which made them sensitive to human triggers for a couple days. Yesterday I found avalanches were possible on wind loaded slopes in the northern Bridger Range (video). These instabilities generally stabilize quickly. With little new snow this weekend and a lack of wind loading over the last 24 hours, avalanches are not likely or very small today.
Isolated small wind slabs or loose snow avalanches can be triggered and are harmful in the wrong terrain (e.g., above cliffs, dense trees, etc.). Cornices along ridgelines are massive throughout the advisory area. They can break farther back than expected and trigger larger slides below (photo, photo). Avoid slopes directly below cornices and travel far back from the edge along ridgelines. Otherwise, the snowpack is 6-12 feet deep and generally stable (video, video).
Avalanche danger today is rated LOW. Small and isolated instabilities exist. Practice safe travel, and continue to attentively assess terrain and snowpack.
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).
Upcoming Avalanche Education and Events
LIVINGSTON
TOMORROW!, March 20, Beer for a Cause Night at Katabatic Brewing, 4-8p.m. A dollar from every pint will be donated to The Friends of the Avalanche Center.
Low danger is not no danger. Our one-page accident report on the avalanche that caught a snowmobiler on Kirkwood Ridge in the southern Madison Range on March 7th is worth looking at: accident report, video.