12-13

GNFAC Avalanche Forecast for Sat Feb 23, 2013

Snowpack and Avalanche Discussion

Northern Madison Range

More than 8 inches of snow has fallen in the past five hours in the mountains around Big Sky. This hefty shot of snow will create an assortment of avalanche problems. The primary avalanche concern will be wind loaded slopes.  Upper elevation terrain leeward to west-southwest winds will receive the heaviest loading.  Today, natural avalanches are likely and human triggered avalanches are very likely on wind loaded slopes which have a HIGH avalanche danger.

We investigated this south facing avalanche that was snowmobile triggered on Tuesday, Feb 19th.  The avalanche was a hard wind slab sitting on facets.  It was up to 3 feet deep and was likely trigggered from the thin part of the slope.  The slide ran 525' vertical and was 300' wide with an average slope angle of 40 degrees.  Thin areas of a slope are where avalanches can be initiated from.  No one was caught.  Photo: GNFAC

Cooke City, 2013-02-22