Final answer:
The three mechanisms that lead to tornadogenesis are wind shear, which creates horizontal rotation in the atmosphere; updrafts, which can tilt the rotating air into a vertical orientation; and the rear flank downdraft, which can tighten and maintain the tornado's structure.
Step-by-step explanation:
Scientists believe there are three primary mechanisms that contribute to tornadogenesis, which is the process of tornado formation.
Mechanism One: Wind Shear
The first mechanism involves wind shear, where winds at different altitudes move at different speeds or directions, creating rotation in the lower atmosphere. This can lead to the formation of a horizontal spinning effect, which, when lifted vertically by a strong updraft, becomes a tornado.
Mechanism Two: Updraft
The second mechanism centers on a strong updraft. When warm, moist air rapidly rises, it can create low pressure underneath. This rising air can tilt the horizontally spinning air into a vertical orientation, thus organizing and intensifying the rotation into a vortex.
Mechanism Three: Rear Flank Downdraft (RFD)
The third mechanism involves the rear flank downdraft (RFD). This is a downdraft that occurs with some supercells (thunderstorms with a deep rotating updraft), which can wrap around the back side of the tornado, tightening the rotation and assisting in the maintenance of the tornado's structure.