National Weather Service introduces impact-based warnings for tornadoes

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On May 22, 2011, a column of rotating air spawned a massive EF-5 tornado, with wind speeds greater than 200 miles per hour, over the city of Joplin, Mo. The twister caught the city off guard, leaving 158 people dead and injuring more than 1,000 people, making it the deadliest tornado in the United States since record-keeping began in 1950.

Document Type: 

  • Case Study


  • critical issues, database publication, weather hazards, hazards