Tornadoes also need atmospheric instability, or the tendency of the air to rise. It provides the fuel and energy for its formation.

LAS VEGAS (KLAS) — A severe thunderstorm warning for north central Clark County on Friday evening brought with it a unique ...

Landspout tornadoes typically form when a boundary causes air to come together underneath a cloud at the same time that there's some rotation in the lowest part of the sky.

Southeast Michigan has seen spin-up tornadoes in the past - ones that form fast and not necessarily along a storm line.