Bridger Range

Wind drifts, primarily at upper elevations, are the major avalanche concern today. Either avoid wind drifts entirely on steep slopes or carefully assess how well they’re bonded to the old snow.

Across the forecast area, the primary avalanche concern is the new snow that fell this week, which in many cases was drifted by strong winds a couple days ago and/or is sitting on top of a variety of weak layers. Differences in how widespread these concerns are and the size, likelihood and type of expected avalanches depend on how much snow fell this week.

Since Monday, it has snowed around 2 ft near Island Park (2.8” Snow Water Equivalent) with 1.5 ft near West Yellowstone (1.5” SWE). With so much new snow and widespread weak layers, triggering large, persistent slab avalanches is likely today and completely avoiding slopes steeper than 30 degrees remains the only prudent choice. Three recent avalanches seen in the Taylor Fork yesterday (details and photos), the avalanche I triggered near Lionhead on Wednesday (video & ob), and skiers experiencing “near constant collapsing” near Hebgen Lake yesterday (observation) clearly demonstrate that the snowpack remains unstable. Don’t overthink things - after a long dry spell there is finally powder to ride, but that also means that conditions are dangerous. Keep it simple and enjoy the new snow while avoiding steep slopes until the new snow and weak layers have some time to settle and stabilize. The avalanche danger is CONSIDERABLE at all elevations near Island Park and West Yellowstone. 

In the Northern Madison and Northern Gallatin Ranges, as well as near Cooke City, it snowed a bit less this week (around a foot), so not every slope is quite as dangerous. But, as I found yesterday in Beehive and Dave saw up Portal Creek, there are variety of weak layers in the upper snowpack (Beehive video, Portal video) and especially where the wind has drifted the new snow into thicker slabs, triggering large avalanches remains likely. A big persistent slab avalanche  in the Lone Lake Cirque on Lone Mountain on Tuesday, and another, somewhat smaller but still 12-18” deep, skier triggered slide yesterday demonstrate this concern. Simply continuing to avoid slopes steeper than 30 degrees remains a simple, viable choice, but you could also reasonably plan to avoid wind drifts and dig to look for and test weak layers in the upper 2 ft of the snowpack before riding more sheltered, steeper slopes. The avalanche is CONSIDERABLE at higher elevations in these areas. 

The Bridger Range has received the least recent snowfall and the avalanche danger is mostly confined to wind loaded slopes. There are also widespread weak layers here, but without a wind drift there isn’t enough of a slab on top to make them much of a problem at the moment. I would either avoid wind drifts entirely on steep slopes or carefully assess how well they’re bonded to the old snow. The avalanche danger is MODERATE in the Bridger Range. 

On a last, sobering note. There have been 11 avalanche deaths, in three separate incidents, across the western U.S. in the last three days (details). Each of these victims left behind a grieving community of friends and family. Please be careful and stay safe out there.