Bridger Range

It remains possible to trigger a 6-12” deep wind slab avalanche on steep slopes where recent drifts sit atop a weak layer of sugary facets. Avoid steep pitches with consequential runouts that have a firm, drum-like surface, often located near ridgelines, in gullies, and below overhanging cornices. Wind-sheltered terrain will have softer snow and generally safe conditions.

Today, wind slab avalanches are the primary avalanche concern. Drifts are sitting atop a layer of weak, sugary snow that formed during the January dry spell (near-surface faceting video), and they remain unstable on some slopes. While you might encounter instability in any of the forecast regions today, the danger is based on the anticipated size of the avalanche and its potential to harm skiers and riders. This afternoon’s snowfall is unlikely to change the danger, but as always, clue into changing conditions.

A secondary problem throughout the forecast area is dry loose avalanches or sluffs within the sugary surface snow. On Monday in the Southern Madison Range, my partner and I triggered loose snow avalanches running the width of our skis and up to a foot deep, entraining faceted snow as they slid downhill (video). While relatively small and predictable, injuries could result from terrain traps in more extreme terrain.

Last weekend’s low‑density snow in the Bridger and Northern Gallatin Range drifted onto slopes, and on Sunday, skiers and climbers triggered sensitive wind slab avalanches that broke 6-12” deep (Hyalite climbs, Divide Peak, Mt. Blackmore 1, Mt. Blackmore 2, Bridgers 1, Bridgers 2). Conditions are stabilizing, but I’d give it a bit more time before jumping onto steep, wind-loaded slopes with consequential runouts. Wind-sheltered terrain will have softer snow and generally safe conditions. In the Bridger and Northern Gallatin Ranges, the avalanche danger is MODERATE on wind-loaded slopes and LOW on all others.

In the mountains around Big Sky, West Yellowstone, Island Park, and Cooke City, you can find trouble with a thin wind slab avalanche, but you have to go looking for it, and the terrain will drive the consequences. Yesterday, Ian and Mark hunted for unstable drifts at Buck Ridge and Beehive Basin in the Northern Madison Range. Most that they found were less than 3” thick, with one reaching 8” deep in places (Buck video, Beehive video). Guides in Cooke City observed cracking in the snow surface and triggered a small drift near a ridgeline (observation). If you exert minimal effort to avoid obviously wind-loaded slopes, then triggering an avalanche is unlikely, and you’ll find some nice skiing and riding conditions in the thick layer of sugary near-surface facets that make up the top of the snowpack (observation). The danger is LOW in the Cooke City, Lionhead, and Island Park areas, as well as in the Madison and Southern Gallatin Ranges.