What makes a thunderstorm “severe�

[knocker]

 

What exactly distinguishes a “severe†thunderstorm from any other thunderstorm?  The official definition of a “severe†storm may strike you as  arbitrary. According to the National Weather Service, a severe thunderstorm must include winds of 58 MPH or greater, hail one inch in diameter or larger, or a tornado. But why are these the criteria and how did they come about?

 

http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2014/07/09/what-makes-a-thunderstorm-severe/

[Lauren]

Thanks for that, i have always wondered.

[vladthemert]

thanks knocker very informative read something that puzzled me too

[johnholmes]

that is for the states not the UK although it is a good description of what the most severe in the UK might deliver. I cannot find the Met O definition but WMO weather code 97 is how it is described if by a human observer.

[TonyH]

Yeah what applies for the US is irrelevant for our more temperate climes.

However once I did witness such a storm, in Coventry August 1975 - all three occured in that!