11-12
A thin layer of small grained facets were producing signs of instability and unstable results in the Flanders drainage up Hyalite. This layer was most present on slopes above 9,000 ft. Photo GNFAC
Looking up the path of the avalanche that killed a snowmobiler today (Feb 22, 2012). The accident happened immediately off the Miller road towards Daisy Pass outside Cooke City. The slide occurred as he turned his sled around at the road's edge. He was not on a steep slope, nor was the avalanche path obvious. The slide buried and killed the rider. He was dug up quickly but did not survive. Two other riders was partially buried, but uninjured, with arms sticking out of the snow, and a fourth was buried up to his knees.
Forecast link: GNFAC Avalanche Forecast for Thu Feb 23, 2012
The avalanche debris hit the road heading up to Daisy Pass. The avalanche was triggered by a snowmobiler a short distance off the road, but released far above. Photo: B. Zavora
GNFAC Avalanche Advisory for Wed Feb 22, 2012
Snowpack and Avalanche Discussion
The Bridger Range:
Storm totals at 5 a.m. in the Bridger Range were 19 inches of snow and 2.4” of SWE. The avalanche message today is simple: A lot of heavy snow was rapidly added to a very weak and unstable snowpack. Avalanches are very likely.
GNFAC Avalanche Forecast for Tue Feb 21, 2012
Snowpack and Avalanche Discussion
The Bridger, Gallatin and Madison Ranges, the Lionhead area near West Yellowstone and the mountains around Cooke City:
If you enter avalanche terrain today you will likely trigger an avalanche. Today is not a day to trifle with the snowpack. It’s ornery and getting more dangerous as more snow falls and wind blows.
A skier triggered two small slides near Divide Peak up Hyalite. The snow is breaking on a layer of near surface facets under the new snow. This layer is widespread throughout southwest Montana and will become more reactive as more snow falls. Photo: B. VandenBos
Forecast link: GNFAC Avalanche Forecast for Tue Feb 21, 2012
This avalanche happened yesterday and was triggered by a skier in between the two crown faces seen in this photo. This 40 degree, southwest facing slope broke 1 foot deep, 500 feet wide and ran 300 vertical feet. It failed on near surface facets that were formed during last week's clear weather. Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Tue Feb 21, 2012