Please Consider the Funnel of a Tornado Which Holds Its

Essay

Please consider the funnel of a tornado which holds its size (radius) and therefore its rotation rate. Now imagine that the funnel is made up of many tiny particles moving around in circles. You are examining one of those particles, which represents a tiny portion of the funnel cloud. You may ignore gravity for this problem.
-Why would it make sense if we said that air is moving very rapidly up through the center of the funnel and almost stationary outside the funnel for it to remain in uniform circular motion?