Classifying Avalanches

This avalanche was triggered with explosives (avalauncher) and was 200’ wide, 2-7’ deep, with an average depth of 3’ and ran 800 vertical feet, it encompassed about 40% of the avalanche path, running on snow deposited 2 months earlier and the crown was 4F hardness. Classify it using shorthand.

This Avalanche occurred unobserved during a significant March Storm. The crown face was measures at 5-10’ deep and over 1 mile in length. The snow at the crown was so hard, you couldn’t push a pencil into it. It ran to the bottom of the canyon, up the other side before turning down the drainage. Medium stand of Aspen trees and a few large conifers were destroyed. Classify using shorthand.

This avalanche was unintentionally triggered by a snowboarder riding the slope. The crown was 12-24” deep and about 300’ wide. It was 4F hardness and ran about 250 vertical feet. The avalanche failed on buried surface hoar and the rider was carried into the trees, suffering a fractured leg and a broken snowboard. Classify using shorthand.