Backyard Avalanche

April 12, 2021

Pre-Avalanche  (1)

Photographer: George Seielstad 
Summary Authors: George Seielstad; Jim Foster

Seldom does an avalanche occur on your outside deck, but conditions in February of 2021 created one at my home in western Montana. A snowy start to the month was followed by continuously cold weather through mid-February when only on one day did the thermometer reach freezing (32 F or 0 C).

Shown above is a glass-topped table with rounded edges having a slight tilt. After snow piled up on the table, a meltwater lens allowed the load to gradually slide slowly off the downhill edge. Notice how the curved edge is rounded on the underside of the table. This demonstrates snow's substantial tensile strength. Photos taken on February 19, 2021.