Shortly before I arrived on 12-28-06, a snowmobiler triggered this small wind slab avalanche above the White Pine Lake Trail.

The 60'-wide hard slab avalanche averaged around 1' deep.  The east-southeast facing slope at around 9000' in elevation is just a little steeper than 35 degrees.

Two sets of snowmobile tracks entered the avalanche and thankfully, two sets exited as well.

The wind-deposited slab buried under 4 to 6 inches of powder was pencil to 1-finger in hardness.  It failed just above a solid sun-crust on a thin sugary weak layer, in which I found some intact frost or surface hoar crystals.

The deposition was made up of solid chunks of hard slab.

Even though this slide may have been small and easy to escape while riding on your machine, we'd really love to hear about it because slopes with a more significant wind load could produce larger, more dangerous avalanches.  Remember, the backcountry observations you send in to us may help save lives.

This time everything turned out fine, and it might have been pretty fun to trigger this small avalanche.  The problem is, next time the same slope might produce a larger avalanche, and this particular slope has a good example of a group of trees as a dangerous terrain trap directly in the avalanche's fall-line.

Here's a look at the slope in Upper Bunch Grass, near where guest forecaster, Dave Kikkert, intentionally triggered a nice hard slab avalanche with a cornice drop a couple days ago, on 12-26-06.