GNFAC Avalanche Forecast for Sun Mar 7, 2021

Not the Current Forecast

Good Morning. This is Alex Marienthal with the Gallatin National Forest Avalanche Forecast on Sunday, March 7th at 7:15 a.m. Today’s forecast is sponsored by Grizzly Outfitters and Cooke City Super 8/Bearclaw Bob’s. This forecast does not apply to operating ski areas.

Mountain Weather

Last night the Bridger Range got 4” of snow, Big Sky got 1” and elsewhere got none. This morning, under mostly cloudy skies, temperatures are teens to mid-20s F and wind is southwest at 10-15 mph with gusts of 25-35 mph. Skies will become mostly sunny this afternoon with temperatures reaching high 30s F and southwest wind at 10-25 mph. The next chance for snow is Monday night.

Snowpack and Avalanche Discussion

In the Bridgers, 4” inches of new snow equal to 0.5” of snow water equivalent (SWE) and moderate southwest wind formed fresh drifts along ridgelines. If you see these drifts crack under your skis, it is a sign they are unstable and steeper wind-loaded slopes should be avoided. This afternoon, sunshine and above freezing temperatures could make the new snow moist and make it possible to trigger wet loose avalanches. These slides can appear small, but are powerful and potentially deadly if they catch you in high consequence terrain. Additionally, a small slide or a human can trigger large to very large avalanches on weak snow near the ground. These deep slabs are becoming more difficult to trigger, but new snow today keeps it possible. Avoid travel on and underneath steep, sunny slopes this afternoon, and carefully evaluate stability of new snow and fresh drifts. Today avalanche danger is MODERATE.

In the mountains south of Bozeman to West Yellowstone weak snow near the ground creates an unstable structure, and skiers or riders can trigger large to very large deep slab avalanches. I skied in Beehive Basin yesterday and found the faceted snow near the ground is still very soft and weak (video). A skier near Maid of the Mist in Hyalite saw deep avalanche crowns (photo, photo), and we received a photo of a huge slide in the southern Madisons. These broke in the last week or two and remind us what is possible. Deep slabs are getting more difficult to trigger each day without snow or wind-loading, but the potential large consequences require conservative travel choices and diligent snowpack assessment. Today there is a lingering possibility to trigger a deep slab avalanche and avalanche danger is MODERATE.

On slopes that receive direct sun, surface crusts will be slow to melt due to clouds this morning and cooler temperatures than recent days, and wet snow avalanches are unlikely. Remain cautious of steep, sunny slopes this afternoon if the snow surface becomes wet.

In the mountains near Cooke City the snowpack lacks widespread buried weak layers and avalanches are unlikely. Be cautious of small wet loose avalanches later in the day on slopes that receive direct sun. Before riding steep slopes, assess the snowpack for buried weak layers. A couple recent natural avalanches west of Cooke City, outside our advisory area, should keep us on our toes and show the type of slopes where unstable weak layers may exist (photo and details, photo). The avalanche danger is LOW in the mountains near Cooke City.

If you get out, please send us your observations no matter how brief. You can submit them via our website, email (, 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.

The Last Word

Accident reports have now been posted for many of February’s tragic avalanche fatalities across the western US. Take a bit of time to read them and try to find lessons to help yourself become a safer backcountry traveller.

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