GNFAC Avalanche Forecast for Thu Dec 12, 2024
This is Mark Staples with the avalanche forecast for Thursday, December 12th at 7:00 am. This information is sponsored by the Bozeman Ice Festival, Alpine Orthopedics & Sports Medicine, and Stronghold Fabrication. This forecast does not apply to operating ski areas.
*Bridger Bowl is now closed to uphill travel in preparation for opening day tomorrow
Overnight a trace of snow fell in some areas while others remained dry.
This morning, temperatures are mostly in the mid to upper teens F. Winds have generally been blowing from the W, a little from the NW and a little from the SW in places. Ridgetop wind speeds are averaging about 15 mph gusting 20-30 mph. They blew pretty strong on Tuesday moving lots of snow but haven’t increased since then.
Today will be mostly cloudy with high temperatures rising into the 20s F. Wind speeds will be similar today as they are this morning but will slowly shift direction and blow more from the SW.
A quick-moving storm is still on track to bring more snow on Sunday favoring areas near West Yellowstone and Island Park
After fresh snow Monday followed by strong winds on Tuesday, the main avalanche problem to look for and avoid are wind slabs that are a day or two old. Seek out slopes untouched by the wind with soft powder.
Complicating the situation is that the old snow surface became faceted and weak and is now buried by new snow. Near Cooke City, Alex found a buried layer of surface hoar (see the stripe in in his snowpit wall in the photo). There have been no reports of avalanches on this faceted snow or surface hoar which is especially notable in Hyalite where up to 15 inches of snow had fallen by Monday. For now it appears that the new snow did not create a persistent slab avalanche problem yet, but the stage has been set.
For today, human triggered avalanches remain possible and the avalanche danger is MODERATE.
Less snow fell in areas further south near West Yellowstone and Island Park (about 2-4 inches by Monday morning), but it was enough to cap the old snow surface which had become weak and faceted. Surface hoar was also buried as well as Dave describes in this video from Island Park.
Isolated areas with wind deposited snow may have enough to cause an avalanche; otherwise, human triggered avalanches are unlikely and the avalanche danger is LOW.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar
Tonight, Thursday, Dec 12, attend a free 1-hr avalanche awareness talk at 6:00 PM at REI Bozeman.
Tomorrow, Friday, Dec 13, attend a free motorized avalanche awareness talk at Basecamp Gallatin in Four Corners from 6:30 to 8 pm from Six Points Avalanche Education.
This Friday, Saturday, or Sunday - Take an intro class with a field day. Register for our Avalanche Fundamentals course.
Friends of the Avalanche Center: Fall Fundraiser!
We’re still counting on your support and the online Fall Powder Blast fundraiser is 79% of the way to our goal. Please consider making even a small donation HERE or via Venmo