A supercell thunderstrom in Oklahoma ... Hail that is at least quarter size (1 inch diameter or larger) And/or wind gusts 58 mph or greater And/or a tornado If a storm that meets these criteria ...

A supercell is a severe variety of thunderstorm caused by a change in wind speed and direction. More stories from around Yorkshire BBC Weather forecaster Billy Payne said: "We don't see supercells ...