  Processes related to the production of vorticity in the forward and rear
flank downdrafts and their interaction with the boundary layer are thought to
play a role in tornadogenesis. We argue that an inverse energy cascade is a
plausible mechanism for tornadogenesis and tornado maintenance and provide
supporting evidence which is both numerical and observational. We apply a
three-dimensional vortex gas model to supercritical vortices produced at the
surface boundary layer possibly due to interactions of vortices brought to the
surface by the rear flank downdraft and also to those related to the forward
flank downdraft. Two-dimensional and three-dimensional vortex gas models are
discussed, and the three-dimensional vortex gas model of Chorin, developed
further by Flandoli and Gubinelli, is proposed as a model for intense small-
scale subvortices found in tornadoes and in recent numerical studies by Orf et
al. In this paper, the smaller scales are represented by intense, supercritical
vortices, which transfer energy to the larger-scale tornadic flows (inverse
energy cascade). We address the formation of these vortices as a result of the
interaction of the flow with the surface and a boundary layer.
