Southwest winds drifted fresh snow onto steep lee slopes plagued by buried weak layers, and on 2-21-07 a few natural avalanches were apparent.  This avalanche in upper Steep Hollow is around 400' wide and 2+ feet deep.

The avalanche on a 40 degree northeast facing slope indicates that others are possible on nearby slopes.  Here's a view up the south flank.

The avalanche produced a huge pile of debris on the bench below the steep slope.  The pile could have buried my snowmobile under 20 feet of concrete-like snow.

The Avalanche ran around 500 vertical feet and produced a destructive air-blast.

My ski pole is dwarfed by the crown on the north side of the crown.  I am encouraged that the suspect slopes in the background remain untracked since Monday's storm.  Shows that folks are getting the idea and avoiding steep wind drifted slopes. 

The avalanche took a lot of rotten snow old snow from January and December down-slope with the slab leaving a moonscape bed surface.

This snowmobiler triggered wind slab near Logan Summit is on a low angled slope, so the avalanche only ran a few feet and the slab stayed pretty well intact.