Kicked off a wind slab avalanche 25ft wide on the west ridge of beehive basin. The wind slab was around 8-10ft deep and the debris slid almost to the flat a few hundred feet down the slope. The slide occurred around 9100ft on the east aspect. Neither me nor my partner were carried or caught in the slide.
The windslab that broke off was about 8-10 feet tall. It was mostly a huge section of a cornice that broke and the slope it fell down onto seemed to propagate a few inches down as well. The majority of the debris was from the cornice.
Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Cornice fall
Trigger
Snowboarder
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
Kicked off a wind slab avalanche 25ft wide on the west ridge of beehive basin. The wind slab was around 8-10ft deep and the debris slid almost to the flat a few hundred feet down the slope. The slide occurred around 9100ft on the east aspect. Neither me nor my partner were carried or caught in the slide.
The windslab that broke off was about 8-10 feet tall. It was mostly a huge section of a cornice that broke and the slope it fell down onto seemed to propagate a few inches down as well. The majority of the debris was from the cornice.
Riding in this morning, we saw this older wet slide on the Portal Creek road down low at about 6400' in elevation on a south facing slope by lots of exposed rocks. For reference, Gallatin River is 5800' in this area.
We didn't see any fresh ones on our way out at about 2:30.
The most likely places for big wet slides are slopes or areas with exposed rocks and cliffs. Generally these wet slides happen a little predictably in the afternoon as the snow gets wet. We know what time of day they'll happen, but it's hard to know exactly when they'll release, so watch out when the snow is obviously wet if traveling under slopes like this.
You don't need to worry about them in the morning, when the snow is frozen. What a nasty avalanche with sticks, rocks, and dirt in it?
We toured up to the prayer flags on the Ridge above Beehive Basin, got a good view around the basins, dug to the south of the cornice line there, and descended the south side of Tyler's path. Clear skies, slightly above freezing temperatures, and calm wind. The surface conditions were better than I would have expected, with dry snow/ no crust on all aspects other than those tilted south-facing. The lower elevation snow in the basin was getting wet by the time we departed at 2 PM. I would expect some wet loose avalanches this afternoon. No wind loading or signs of instability observed.
Our pit showed good stability (ECTX). This fits with the pattern of avalanche activity driven by snowy and windy periods that quickly improves with milder conditions in the mountains around Bozeman and Big Sky. We are optimistic about the nice weather and generally safe conditions coming up this weekend.
Watch out for these three things and you will be looking good to get into a fair amount of fun terrain this weekend in the Bridger, Northern Madison and Northern Gallatin Ranges, and the Centennial Mountains in Island Park:
Wind-loaded terrain where you could find lingering wind slab instability.
Cornices: They are really big currently, and we may see a few breaking off with the warm temperatures this weekend. These can collapse much farther back from the edge than expected.
Wet snow: With forecasts calling for above freezing temperatures under sunny skies, we expect wet loose snow avalanches to slide on sunnier (south and west) aspects. These will generally be small and involve only the recent snow, but they can still injure or buried skiers, riders and climbers in steep terrain or gullies where they can push backcountry travelers into terrain traps (trees, gullies, cliffs, rocks).
Isolated instability can have significant consequences on larger or committing terrain objectives. Stack the deck in your favor by digging down a few feet and testing the snowpack so you don't get surprised.
