Rapid-Scan Mobile Radar Observations of Tornadogenesis
Historically, the generally accepted hypothesis surrounding tornadogenesis in supercell thunderstorms is referred to as the 'top-down' hypothesis. According to this theory, strong rotation develops above the ground first, followed by progressively strengthening rotation at lower heights until...

This is the paper presenting the "bottom-up" theory of tornadogenesis. Of note is the idea that the RFD is a consequence of the tornado cyclone, not the producer of it.Historically, the generally accepted hypothesis surrounding tornadogenesis in supercell thunderstorms is referred to as the 'top-down' hypothesis. According to this theory, strong rotation develops above the ground first, followed by progressively strengthening rotation at lower heights until the vertically rotating column intersects the ground, contracts, and forms a tornado. This paper provides evidence from a novel rapid-scanning mobile Doppler radar (RaXPol) that this hypothesis is likely incorrect. Instead, it appears that in many cases, tornadic-strength rotation develops either at near-ground levels first, or contemporaneously throughout the depth of the tornado-bearing layer.