GNFAC Avalanche Forecast for Fri Mar 7, 2025
<p><span><span><span><strong><span><span>Wind Slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>breaking</span></span></span></span></span></span><span><span><span><strong><span><span> </span></span></strong></span></span></span><span><span><span><span><span><span>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 (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34519"><span><span><span><span><span><…;). Steer around the deepest wind drifts today in steep terrain and give them a little bit more time to bond.</span></span></span></span></span></span></p>
<p><span><span><span><strong><span><span>Persistent Slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>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 </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34421"><span><span><span><span><span><…; and </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34413"><span><span><span><span><span><… Creek</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>). 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. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is MODERATE today.</span></span></span></span></span></span></p>
<p><span><span><span><strong><span><span>Wind slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>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 (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34517"><span><span><span><span><span><…;). I expect similar wind slabs to be easily triggered today as well. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>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. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Human triggered avalanches are possible and the avalanche danger is MODERATE.</span></span></span></span></span></span></p>
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar
Instability in the New and Wind Drifted Snow
We toured from the dam up the north ridge to Trapper. Light snow fell throughout the day, adding up to about 6". As we descended the east-facing bowl, cracks shot out from our skis on slopes with a subtle wind effect. Avalanches within the new and wind-drifted snow were likely, but the volume would have been relatively small and mostly concerning in technical terrain or in the presence of terrain traps. There was a new facet layer below the melt-freeze crust. It is TBD if it will be a problem.
The other problem is continued concern about avalanches breaking 2-3 feet deep on weak layers formed during the January dry spell. The snowpack structure is weak in this area, similar to the slopes that most recently produced human-triggered avalanches in Cabin Creek, Tepee Basin, and Lionhead. Pole probing indicated this poor structure was widespread. Our pit at 9000' on a northeast-facing slope yielded an ECTP28 on the 4F- facet layer formed in January. Failures on these deep layers don't seem very likely, but, for now, step back from steep terrain to let the storm play out. Once the storm ends, we will reevaluate stability and proceed from there. While the actual likelihood is debatable, the consequences of getting caught in a slide breaking on these weak layers are not.
Dry loose / wind slabs in the Centennials
8-12 inches of new snow on the ground in the Centennials near Nemesis mtn. New snow that fell early this morning was very touchy on hard/icy surfaces from the melt/freeze activity we saw the prior days.
Loose snow avalanches around Blackmore
Saw lots of small loose avalanches on Mt Blackmore and nearby slopes, some appeared to be natural and others skier triggered. We saw multiple dry loose on N and E aspects and a wet loose on a southeast aspect.
We also noticed recent wind loading on the southeast side of ridgetops and scouring on north slopes.
Saw lots of small loose avalanches on Mt Blackmore and nearby slopes, some appeared to be natural and others skier triggered. We saw multiple dry loose on N and E aspects and a wet loose on a southeast aspect. Photo: H Meyers
Saw lots of small loose avalanches on Mt Blackmore and nearby slopes, some appeared to be natural and others skier triggered. We saw multiple dry loose on N and E aspects and a wet loose on a southeast aspect. Photo: H Meyers
south of Cooke obs
No Recent avalanche activity observed in Hayden Creek or Republic Creek today with the the exception of some small dry loose in steep terrain. No Collapsing or Cracking during our day out today. 2" new at 8700' at 9am with another inch throughout the day. East winds were light throughout the day.