Mesocyclone

Part of speech: noun

Definitions

1. A specific rotating column of air within a thunderstorm that can extend vertically and is often linked to severe weather events like tornadoes
2. This phenomenon involves a distinct circulation pattern associated with intense storms, capable of developing into tornadoes under certain atmospheric conditions
3. A particular type of rotating air mass occurring in a thunderstorm that can lead to severe weather, such as tornado formation, in specific meteorological circumstances

Etymology: Meteorologists needed a name for a storm within a storm, and "mesocyclone" was built to fit that gap. The word is a compound of "meso-", from Ancient Greek "mesos", meaning "middle" or "intermediate", and "cyclone", which itself comes from Ancient Greek "kuklos", meaning "circle" or "wheel". Put together, the parts describe a rotating circulation of intermediate size, larger than a single thunder cell but smaller than the whole weather system around it. The "cyclone" half has an unexpected history of its own. Early 19th-century English writers borrowed it from modern Latin "cyclon", a word coined in the 1840s by Henry Piddington, a British meteorologist working in India, who chose the Greek root for "coil" because the storms he studied spun in circles. The "meso-" prefix is a modern scientific addition, attached to the older term in the mid-20th century to name the rotating updraft at the heart of a supercell thunderstorm.