Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Monday, February 24th at 7:00 a.m. Today’s forecast is sponsored by Beartooth Powder Guides and Bridger Bowl. This forecast does not apply to operating ski areas.
Last night wind gusted 40-50 mph before a squall of snow delivered 2-3” near Bozeman, Big Sky and Cooke City with 1-2” near West Yellowstone. This morning temperatures are single digits to teens F and wind is west-northwest at 15-30 mph with gusts of 30-45 mph. Today temperatures will be teens to low 20s F with west-northwest wind at 20-30 mph. Snow showers will continue through tonight. By morning the mountains will have 6-12” of low density snow near Bozeman and Big Sky with 4-6” near Cooke City and 2-3” near West Yellowstone.
Today new snow and moderate wind create fresh slabs that can be triggered by a skier or snowmobiler. These fresh slabs increase the possibility of avalanches breaking 3-5 feet deep on weak sugary snow at the base of the snowpack. Through February we witnessed a widespread deep slab avalanche cycle in the Bridger Range, Hyalite and near Big Sky. Dozens of slopes avalanched with many slides snapping trees and running their maximum runout distance (Saddle Peak, Truman Gulch, Maid of the Mist, Blackmore, Wheeler, Emigrant). Avalanches broke on all aspects and elevations, and there were relatively large avalanches in unusual areas like Chestnut Mountain and Lick Creek. Natural deep slab avalanches broke with relatively small additional storms as snowfall slowed down a week ago (photo, photo). Slopes that did not slide yet this season are near their breaking point, and with new snow and wind-loading today I do not trust those slopes.
Over the weekend a snowmobiler triggered a small slide on Scotch Bonnet near Cooke City (photo), and skiers saw a large natural avalanche on the Sphinx in the Madison Range (photo). Weak layers might not be ready to hold this next storm, no matter how big. Browse the avalanche activity on our website to see where recent avalanches occurred and avoid similar terrain. Additionally, slopes that avalanched already this season should not be assumed stable. Carefully assess the stability of the new snow that sits on potentially weak bed surfaces of old slides.
Today, new snow, wind and buried weak layers create heightened avalanche conditions. Anticipate stability to decrease and take a step back from larger, committing objectives. Avalanche danger is MODERATE and will increase to CONSIDERABLE on wind loaded slopes where large natural avalanches are possible as snow and wind add weight this afternoon
The southern Madison Range, southern Gallatin Range and Lionhead area near West Yellowstone got a couple inches of snow last night with a couple more expected today. The snowpack there handled the February storms better than the rest of the advisory area. Doug and Ian rode into Cabin Creek last Wednesday and found a generally stable snowpack (video). Today moderate to strong wind will drift new snow into fresh slabs that are possible to trigger. Watch for cracking of the snow surface or snow blowing across ridgelines as a sign fresh drifts are unstable. Avalanches are possible on wind loaded slopes where danger is MODERATE. On non-wind loaded slopes avalanches are unlikely and danger is LOW.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out and plan to attend one or two: Events and Education Calendar.
Every Friday and Saturday, Snowpack Update and Rescue Training. Friday, 6:30-7:30 p.m. at the Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.
March 4, 1-hr Avalanche Awareness. 6-7 p.m. at REI.
February 27 - March 1, Bozeman Splitfest, More info and schedule here.
On Saturday 2/15, three motorized snowbikers were caught in an avalanche in Colorado and two were killed. The full accident report is now available here. Please take the time to learn what we can from this and all accidents.