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GNFAC Avalanche Forecast for Sun Jan 29, 2012

Snowpack and Avalanche Discussion

 The southern Madison and southern Gallatin Ranges, Lionhead area near West Yellowstone and mountains around Cooke City:

The mountains near West Yellowstone have a snowpack structure similar to a lead safe balancing precariously on stacked wine glasses.  This fragile balance will continue as long as a major disruption i.e...new snow, wind loading or a skier/snowmobiler does not facilitate additional stress. 

GNFAC Avalanche Forecast for Sat Jan 28, 2012

Snowpack and Avalanche Discussion

The southern Madison and southern Gallatin Ranges, the Lionhead area near West Yellowstone, and the mountains around Cooke City:

The weakest and most unstable snowpack exists near West Yellowstone. On all slopes, the bottom half of the snowpack contains weak facets which will be evident when you step off your sled or out of your skis and sink to the ground. Unfortunately this situation will not change any time soon. Without any new snow, natural avalanche activity has subsided, but human triggered avalanches remain likely.

This natural avalanche occurred recently just south of Silver Gate on a ENE facing slope around 9000ft.  It appears to be wind loaded from the left side, but it propagated of a wide area indicating the existence of a widespread, persistent weak layer.  Photo: B. Zavora

Cooke City, 2012-01-28