Nearly 3 feet of dense, well bonded snow makes up the snowpack above 8,000 ft. in the Lionhead area near West Yellowstone. No discernible weak layers were found during stability tests. This pack is capable of supporting a large load and is a strong foundation for future storms. Photo GNFAC
No matter how hard I try, I just can't get used to rain in December. Fortunately, valley rain this time of year usually translates into mountain snow.
The line between snow and rain was a moving target, but above 7,500 feet snowfall was the primary precipitation type. The snow water equivalent (SWE) was substantial even if the snowfall amounts were not. One inch of SWE fell in the Bridger and southern Madison Ranges including the area around Cooke City. West Yellowstone got close to 2 inches of SWE in some areas. Even though this snow is dense, the ridgetop winds will have no problem blowing it around creating wind drifts.
The snowpack near Cooke City mostly lacks faceted weak layers in the snowpack. Some pockets of thinner and weaker snow may exist. Avalanche activity should occur in the storm snow and and on slopes with fresh wind slabs. Photo: GNFAC
Over the past 48 hours 4-5 inches of high density snow has fallen in the mountains around West Yellowstone and Cooke City; 1-2 inches has fallen in the mountains around Bozeman and Big Sky. This marks the third snow event in the past seven days, a vast improvement over last season when our area went nearly 40 days without snow. This latest round of snow isn’t enough to produce widespread avalanche problems, but is something to consider as more storms impact southwest Montana this weekend.
