The pyroclastic flow deposits red-hot material on the slope of the volcano. After a few minutes, air heated by the deposit establishes a convective regime and due to the speed of the rising air a series of small tornados are formed.
Tornadoes get their start from thunderstorms, and the central United States is a perfect thunderstorm factory because it has just what they need to get started: warm, humid air colliding with cool, dry air. These conditions spawn more than 600 tornadoes, on average, in the United States every year.
At 2:23 pm on June 11, 2004, severe storms researcher Tim Samaras captured something on video no one ever had before: the inside of a tornado.
Samaras designed a special “probe” outfitted with cameras and an audio recorder and built to stay put in a twister. Along with two colleagues, he chased down a tornado near Storm Lake, Iowa, and placed the probe directly in its path.
Catching the inside of a roaring twister on video may sound exciting (or crazy), but it isn’t for thrills. By analyzing the video frame by frame, researchers can do something never successfully done before: calculate wind speeds in the bottom 30 feet (10 meters) of a tornado, where the damage happens.
“27 years ago, Edmonton was struck by a F4 tornado that killed 27 people, injured over 300, and caused more than $332.27 million in damage. Inspired by the overwhelming community response to the disaster, former mayor Laurence Decore called Edmonton a “City of Champions.” Unfortunately, the slogan has lost its original meaning over time as many associated it with the local sport franchises. Few widely-known tributes exist, including a song by the Rural Alberta Advantage and a privately-grown memorial tree.”