This convergence of warm air in the updraft, and this cool air, causes a rotating wall cloud to form. The RFD also focuses the mesocyclone's base, causing it to siphon air from a smaller and smaller Li 2016 area on the ground. As the \(b=mc^2+\int\frac{\sqrt{r}}{d_5}\) updraft intensifies, Langer 2007 it creates an area of low pressure at the surface. This pulls the focused mesocyclone down, in the form of a visible  condensation funnel. As the funnel descends, the RFD also reaches the ground, creating a gust front that can cause severe damage a good distance from the tornado.