The avalanche danger has been dropping with no new snow and mild temps, but conditions were very dangerous just 5 days ago. While the likelihood of triggering an avalanche has gone down, weak snow still lurks near the ground and can cause a big persistent slab avalanche. Because of this potential and two recent avalanches, I’d avoid avalanche terrain today.
The photo from just yesterday show a really big persistent slab avalanche telling us this problem is still a major concern even though the likelihood of triggering one has gone down.
(12/31/2025)
Spotted from a home through spotting scope, but appears to be very large avalanche.
Welcome 2026! We’re fortunate to have relatively great snow coverage (especially compared to other parts of the country). Low elevation snow coverage has been limited due to warm weather and rain. The other challenge has been many downed trees from a prolonged wind event in mid-December.
Wind slabs are always a concern and worth considering in your travels, but most have stabilized due to time and warm temps.
That leaves persistent slab avalanches as the main problem which vary a lot across the forecast area. The weak layer responsible for this problem is October snow near the ground that faceted during dry weather in November.
The mountains near Cooke City were pummeled with snow in December with 140” of snow (16.5” water) and 59 avalanches were recorded. Many were huge persistent slab avalanches with the last significant one occurring just three days ago. The slides have become difficult to trigger because the snowpack is so deep, so likely areas to trigger one will be rocky areas with vaiable snow depths where you can hit a relatively thin spot in the snow.
In the southern Madison and Gallatin Ranges, the Lionhead area, and the Island Park area, the persistent slab avalanche problem reared up and showed itself with a huge slide just a day or two ago someone spotted north of Targhee Peak in the Lionhead area. Another avalanche happened 3 days ago along Lionhead Ridge. While the overall likelihood of triggering these slides has gone down, remember the danger was HIGH just 5 days ago, and I’d still avoid avalanche terrain. I suspect the danger is more acute around Lionhead where the snowpack is a bit thinner.
In the northern Madison and Gallatin Ranges, there have been 22 persistent slab avalanches recorded with the last ones happening 4-5 days ago along Buck Ridge. The most likely places for this problem today will be at upper elevation slopes that have remained cold and received some wind loading.
The Bridger Range was raked by downhill winds this past weekend and had especially warm temperatures this week. In terms of avalanches, it’s been quiet. There have been 13 recorded avalanches this season with only 2 persistent slab avalanches on Dec 5 and 7th. As always there may be a wind slab or two that could be triggered, but avalanche conditions are generally safe.
Across most of the forecast area the avalanche danger is MODERATE with some critical differences explained above. The exception is the Bridger Range where the danger is LOW.
