mesocyclone

/ˌmɛzoʊˈsaɪkloʊn/
noun
  1. A rotating column of air within a thunderstorm, often leading to severe weather like tornadoes.
    • Storm chasers drove toward the mesocyclone to study its rotation.
    • The meteorologist spotted a mesocyclone on the radar and issued a tornado warning.
    • A strong mesocyclone can produce hail, high winds, and dangerous tornadoes.