Tornado
a whirlwind, usually coming on suddenly, continuing but a brief period, and covering only a small area.
It is generally accompanied by rain, lightning, and thunder. It is of the same type of storm as a cyclone, but more local, covering a smaller area, and generally less violent, though still sufficiently so to be highly dangerous. The term tornado is used specifically of rotating or spiral storms in the South Indian Ocean, and those on the coasts of Africa and North America.