The Gallatin National Forest Avalanche Cente r says that avalanche danger in southwest Montana is rated as high on wind-loaded slopes with the most recent snow moving across the region. The high rating is ranked 4 on a scale of 5.
The 24-hour snowfall is 10”-15” in the mountains between West Yellowstone through the Madison and Gallatin ranges with the same amount in the Bridger mountains. The Avalanche Center says that the avalanche story is as simple as it gets. Heavy snow on Wednesday that continues through your Thursday and Friday could easily trigger natural avalanches on wind-loaded slopes. Any activity on steep slopes could very easily cause a slide.
According the Doug Chabot, you should avoid avalanche terrain. Wind loaded slopes are rated as high with a considerable rating on all other slopes.
The current forecast calls for additional mountain snow with storm totals in some areas ranging from 20”-32” by Friday afternoon. The current set-up has most of the moisture held in the middle atmosphere with considerable lift in the upper atmosphere. That will provide ample opportunity to see that snow continue in the high mountain ranges even as valley snow wains.
As always, the GNFAC wants you to stay safe in the backcountry. Always pack a beacon, shovel, and a probe and travel with a partner when heading into avalanche terrain.