Tornadic supercell thunderstorm over a plain in Mycroft, Wyoming, US. Supercell thunderstorms rotate with immense energy, causing a strong updraft and severe weather, including tornadoes, hail, heavy rain, lightning and heavy winds. Inside these severe long-lived storms the wind speed and direction changes with height. This produces a strong rotating updraft of warm air (a mesocyclone) as well as a separate downdraft of cold air. Around a third of supercells produce tornadoes and are termed tornadic.

Picture: Science Photo Library / Rex Features