GNFAC Avalanche Forecast for Fri Feb 26, 2021

Not the Current Forecast

Good Morning. This is Ian Hoyer with the Gallatin National Forest Avalanche Forecast on Friday, February 26th at 7:30 a.m. Today's forecast is sponsored by Blitz Motorsports and Yamaha and Montana Chevy Dealers. This forecast does not apply to operating ski areas.

Mountain Weather

This morning there are 2-5” of new snow around Big Sky, West Yellowstone, and Cooke City while the mountains near Bozeman stayed dry. Winds are 15-25 mph out of the south and west, with gusts of 40-50 mph. Similar winds will continue today, with peak gusts maybe backing off a little bit. Temperatures are in the single digits and teens F and will rise into the teens and low 20s F. Snowfall today and tonight will bring 2-4” by tomorrow morning.

Snowpack and Avalanche Discussion

From Bozeman to West Yellowstone we have two overlapping avalanche concerns today: avalanches breaking under the newly wind-drifted snow and huge avalanches breaking on weak layers near the ground. 

Fresh slabs of wind drifted snow will be easily triggered today. Yesterday we got reports of active wind loading across the northern ranges. With fresh snow overnight in the southern ranges and strong winds today new wind drifts are forming and older drifts will grow larger. While these wind slabs can break deep enough to be problematic all on their own, the big concern is that it may step down to the deeply buried weak layers and pull out the whole season’s snowpack.

Deep slab avalanches are our primary concern today. Over the last week we’ve seen deep avalanches in Hyalite (video, photo, photo), Buck Ridge (McAtee Basin video), and on Lone Peak (photo). Yesterday we got reports of another very large avalanche near Big Sky, on Cedar Mountain (photo). The likelihood of triggering one of these slides isn’t super high, but the recent natural and human triggered slides show it is clearly a possibility. If you do trigger one, it is likely to be unsurvivable. With weak snow at the ground on basically every slope, all steep slopes are suspect. Unfortunately, there is really no way to effectively assess these weak layers. Avoidance is the only safe way to deal with this deep slab problem. Stay off of, and out from under, slopes steeper than 30 degrees to keep from waking the sleeping dragon at the base of the snowpack.

With deep, dangerous avalanches possible the avalanche danger is rated MODERATE.

In Cooke City, avalanches on wind loaded slopes are our primary concern. During the last snow and wind event (Monday into Tuesday), a number of wind slab avalanches and cornices broke (video). These slides are becoming more difficult to trigger, but I still don’t trust steep, windloaded slopes. Also, keep in the back of your mind the possibility of weak snow at the ground. It isn’t widespread, but could catch you off guard with a much deeper, wider avalanche. For today the avalanche danger is rated MODERATE on all slopes. 

If you get out, please send us your observations no matter how brief. You can submit them via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).

The Beacon Park at Beall Park in Bozeman is running!

The Friends of the Avalanche Center in partnership with the City of Bozeman put in a Beacon Park at Beall Park. It is located on the north side of the Beall building between N. Bozeman Ave. and the ice rink. Stop by with your avalanche transceiver and do a few practice rescue drills. Your partner will thank you.

Upcoming Avalanche Education and Events

See our education calendar for an up-to-date list of all local classes. Here are a few select upcoming events and opportunities to check out:

Every Saturday in Cooke City, FREE snowpack update and rescue practice at the Round Lake Warming Hut between 10 a.m. and 3 p.m. Poster with More Info.

The Last Word

Yesterday, Alex and I checked out the snowpack up the Main Boulder, south of Big Timber, (outside our advisory area) before this Saturday’s Sweet Grass County Recreation Association Poker Ride. Unfortunately, the snowpack there looks to be as bad as anywhere in our advisory area. There is weak snow at the ground capped by a thick slab of snow - the perfect recipe for a big avalanche. Watch Alex’s video for more.