09-10
GNFAC Avalanche Forecast for Tue Jan 5, 2010
Snowpack and Avalanche Discussion
For the snowpack and avalanche discussion, let's keep one important fact in mind: all our mountain ranges have a common weak layer of buried facets. The frigid temperatures in early December were indiscriminate in weakening our snowpack. Sugary, unbonded, weak snow can be found in most areas. The only difference is the load of snow they've gotten. Today's storm may put significant amounts of snow in areas that have been untested and I expect danger ratings to climb.
Mark Staples points out the weak layer that the avalanche ran on. Large faceted grains, formed by the cold temperatures in early December, was the layer that failed. These sugary grains were overburdened with a thick hard slab 2 feet thick.
Forecast link: GNFAC Avalanche Forecast for Tue Jan 5, 2010
This picture was taken at the crown of the avalanche looking downslope. The avalanche ran 500 vertical feet, but closer to 1,000 feet slope distance.
Forecast link: GNFAC Avalanche Forecast for Tue Jan 5, 2010
This picture is looking down the slide path with the victim's location and toe of the debris marked. Victim was buried 2-3 feet deep against some trees.
Forecast link: GNFAC Avalanche Forecast for Tue Jan 5, 2010
Looking up the path at Scotch Bonnet. The crown was 2 feet deep and the slide was 100 feet wide. The picture was taken from near the victim's location.
Forecast link: GNFAC Avalanche Forecast for Tue Jan 5, 2010
A skier triggered, was caught and buried 3 feet deep in this avalanche. It occurred Sunday, January 3rd. His partner was standing under the rock cliff on the left, and buried to his knees. His partner rescued him and no one suffered injuries.
Forecast link: GNFAC Avalanche Forecast for Tue Jan 5, 2010
GNFAC Avalanche Advisory for Mon Jan 4, 2010
Snowpack and Avalanche Discussion
The southern Madison and southern Gallatin Ranges, the Lionhead Area near West Yellowstone, the mountains around Cooke City and the Washburn Range:
GNFAC Avalanche Advisory for Sun Jan 3, 2010
Snowpack and Avalanche Discussion
The southern Madison and southern Gallatin Ranges, the Lionhead Area near West Yellowstone, the mountains around Cooke City and the Washburn Range: