Good morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Sunday, February 18th at 7:00 a.m. Today’s forecast is sponsored by Alpine Orthopedics & Sports Medicine, Knoff Group Real Estate and Upper Yellowstone Snowmobile Club. This forecast does not apply to operating ski areas.
There is no new snow. Temperatures range from single digits to high 20s F. Overnight wind was out of the southwest at 10-25 mph with gusts of 25-40 mph, and in Cooke City wind was 5-10 mph with gusts to 15 mph. Today, temperatures will reach 20s to low 30s F, and wind will continue from the southwest-west at 10-25 mph. Snow showers are expected, in the southern ranges this morning and northern ranges this evening, with 1-3” possible by tomorrow morning.
All Regions
Stay off avalanche terrain today to avoid being caught in a large, potentially deadly avalanche. Over the last two days there were multiple close calls, natural avalanches, and avalanches triggered remotely from flat terrain hundreds of feet away, clearly showing us the snowpack is very unstable.
- Yesterday in Taylor Fork a rider triggered a slide, was caught, deployed their airbag, got partially buried, and luckily was uninjured (details).
- Near Big Sky, a skier triggered a large avalanche and was luckily not caught (photos), and riders near Cedar Mtn. triggered two big avalanches from flat terrain far below with one of the slides breaking up to 10-12’ deep (photos, photos).
- Another close call occurred on Friday near Cooke City. A rider triggered an avalanche on the north side of Scotch Bonnet which broke 2-4 feet deep and hundreds of feet wide, and nobody was caught (photos).
- On Friday, riders in Portal Creek remotely triggered four avalanches from up to 900 ft away (details), and near Lionhead Ian and I saw a slide that happened during the day, remotely triggered by riders from 150 ft away in a flat meadow above (photos).
- On Thursday, Dave dug a snowpit in Bear Basin and got unremarkable test results but advised ignoring them because of the big picture signs of instability (video). That night, a natural avalanche broke only a couple hundred feet away from his snowpit (details).
- Yesterday another large fresh natural avalanche was reported by riders on Buck Ridge (photo).
The mountains are yelling at us to stay off of and out from underneath slopes steeper than 30 degrees. Plan your routes carefully. Don’t trust the snowpack, even if you don’t see obvious signs of instability such as collapsing, nearby avalanches, or poor test scores. The overwhelming amount of avalanches and collapsing throughout the forecast area over the last month and a half cannot be ignored (avalanche and weather log).
Moderate to strong winds overnight and today will drift snow into thicker slabs which will make wind-loaded slopes easier to trigger and possibly break naturally. Either way, weak sugary snow at the base of the snowpack makes it likely for a person to trigger a large avalanche on all steep slopes today, whether wind-loaded or not. Dangerous avalanche conditions exist and the avalanche danger is CONSIDERABLE.
If you venture out, please fill an observation form. It does not need to be technical. Did you see any avalanches? How much snow is on the ground? Was the wind moving snow? Simple observations are incredibly valuable. You can also contact us via email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Every weekend in Cooke City: Friday at The Antlers at 7 p.m., Free Avalanche Awareness and Current Conditions talk, and Saturday from 10 a.m.-2 p.m. at Round Lake Warming Hut, Free Rescue Practice.
Loss in the Outdoors is a support group for those affected by loss and grief related to outdoor pursuits. Check out the link for more information
Sadly, there have been four avalanche fatalities in the US this month and eight this year, the most recent last Tuesday in Alaska. Read accident reports to learn more.