This is Ian Hoyer with the avalanche forecast for Friday, March 7th, at 7:00 a.m. sponsored by Yellowstone Club Community Foundation and Idaho State Snowmobile Association - Avalanche Fund. This forecast does not apply to operating ski areas.
Snow totals in the last 24 hours are:
5-6” near Bozeman
3-5” near Big Sky and the Taylor Fork
5” near Island Park
2” in the Lionhead area
1” near Cooke City
Winds have generally been out of the north and east at 5-10 mph with 15-25 mph gusts. In the Bridger Range, winds blew out of the east yesterday at 35 mph with 55 mph gusts, but early this morning dropped dramatically and shifted to the northwest. Temperatures are in the single digits and teens F.
Winds today will be light, shifting to the north and northwest by this afternoon. Temperatures will rise into the 20s and low 30s F. Skies will be mostly sunny.
The next chance for snowfall is early next week.
Wind Slab avalanches breaking up to 1 ft deep are the primary concern today. 5-7” of new snow fell near West Yellowstone in the last 36 hours. Near Cooke City, it only snowed 1” at the Fisher Creek SNOTEL site, but ski guides yesterday reported a little bit more new snow south of town and it snowed 10” nearby in Red Lodge, so there may be places on the fridges of our forecast area with higher snowfall totals. Winds haven’t been too strong, but they’ve been out of the east. Be heads up, as this is an atypical wind direction, so drifts may be in unusual locations. Yesterday, near Hebgen Lake, Dave got shooting cracks in the new snow on slopes with just a touch of wind effect (observation). Steer around the deepest wind drifts today in steep terrain and give them a little bit more time to bond.
Persistent Slab avalanches breaking 2-3 ft deep remain an additional concern. We haven’t seen much activity on these layers recently, but the new snow might be what it takes to wake them back up. If you do trigger a slide on these weak layers, it’ll be deeper, wider, and may break further above you - making it all around substantially more dangerous (rider triggered slides last week at Lionhead and Cabin Creek). You can dig down to look for and test these weak layers, but it’s going to be hard to determine if a particular slope is primed to slide. If you decide to ride in steep terrain today, know that you’re accepting some risk one of these slides may break. After a sunny day today, we’ll have a much better idea if this new snow woke these weak layers back up - so a little patience today could go a long way.
The avalanche danger is MODERATE today.
Wind slab avalanches are also the primary concern around Bozeman, Big Sky, and Island Park. With the east winds, look for drifts in unusual places. Skiers near Island Park yesterday found 8-12” thick, touchy slabs of the new snow (observation). I expect similar wind slabs to be easily triggered today as well.
The lower snowpack in these areas is generally stable, so if you avoid wind drifts, you’re unlikely to trigger a slide today. Plan to avoid wind drifts and pay attention to the feel of the snow under your feet or snowmobile in case you stumble onto a drift by accident. Cracks shooting out in front of you indicate you’ve found an unstable drift and should retreat to low angle terrain.
Human triggered avalanches are possible and the avalanche danger is MODERATE.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar
Avalanche awareness focused on springtime avalanche conditions: Thursday, March 13 at the Bozeman REI from 6-7:30 p.m. The event is free but has limited space and requires registration HERE.
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.