As by far the most intense AVE, the thin column of the  "Series" tornado is very different from its larger cousin, the super cell storm. Although they are found quite close together, they are formed by quite different mechanisms.

essentially acts to energetically flash condense water-vapor into its two primary components, of fresh water and heat energy.

As the condensate falls, heat within the near-vertical vortex column will separate out and rise along the low-pressure, axial core.

Like all atmospheric vortexes, the tornado, is driven by the (~700:1) volumetric collapse that occurs as water-vapor condenses. However, but only if the vortex axis is near-vertical can the phenomenon develop its full energy potential, with a pressure drop of between 40mb-150mb.