Another day without a refreeze and more warm temperatures means you should expect to trigger wet snow avalanches today, they’ll probably break as Wet Loose avalanches, but could also be Wet Slabs. Either one could be large and dangerous. Avoid steep slopes today.
There will certainly be wet loose avalanches today (and they could be quite large), but the bigger threat are wet slabs that may occur as buried persistent weak layers become wet.
Falling cornices trigger avalanches on the slopes below. They also break further back than you'd expect.
Without a solid refreeze, wet snow is again our chief concern.
This warmup has been particularly abrupt for the snowpack around Cooke City, because it had previously stayed cooler than other regions for most of the winter. Yesterday, several natural Wet Slab avalanches released (Woody Ridge, Town Hill). Wet Slabs are notoriously hard to predict, but avalanches yesterday + no freeze overnight + another day of warm temperatures + direct sun this morning sure seems like the recipe for more today. I’m honestly not sure if we’ll see a widespread natural Wet Slab cycle today, but I’d give it a better than 50% chance we do, and it doesn’t really matter, because I am sure that large, dangerous wet snow slides will be easy to trigger, whether they fail as slabs or loose snow. Avoid all steep slopes near Cooke City and give them a wide berth as you pass beneath them, because the avalanche danger is HIGH.
Across the rest of the forecast area, conditions are also dangerous, but the Wet Slab potential is a smidge less. Clouds this afternoon may moderate additional melting a little bit, but there is already plenty of liquid water in the snowpack. Yesterday in the Southern Madison Range, I found a fully saturated snowpack at 9000 ft and a Wet Loose avalanche that had accumulated quite a bit of volume and would have been very dangerous to be caught in (video). There is some amount of wet snow on most slopes - the wetter the snowpack is, the more dangerous it is. Big slab avalanches earlier this week show us that the potential is out there for some huge, unsurvivable slides (Cedar Mt. 1, Cedar Mtn. 2). If you do find a slope with a mostly dry snowpack, you’re not out of the woods, Persistent Slab avalanches are still possible. If you need another reason to avoid steep slopes, Cornices are breaking off and triggering avalanches. Also give them plenty of space if you’re travelling above them on ridgelines.
Do not trust steep slopes today. Expect to trigger wet snow slides - they’ll probably release beneath you as Wet Loose avalanches, but could also break wider and above you as slabs. Avalanche conditions are dangerous and the avalanche danger is CONSIDERABLE near Bozeman, Big Sky, West Yellowstone and Island Park.
