A simple thermodynamical theory for tornadoes

I argue that the simple thermodynamic theory for dust devils, proposed by Renno et al. is general. That is, it also applies also to tornadoes and other convective vortices. The theory is based on the thermodynamics of heat engines and predicts the central pressure and the windspeed of the convective vortices and provides a simple physical interpretation of their general characteristics. Moreover, I show that the thermodynamic method explains windspeeds in excess of 100 m/s at the foot of intense vortices.