Relevant poloidal velocities developing along a streamline in the time-averaged flow of X-b5. All velocities are normalized with the Keplerian velocity at the corresponding foot-point radius. Both the Alfvén point and the fast magnetosonic point are contained within the simulation domain. The blue line indicates the actual poloidal velocity, v_A the local Alfvén speed, c_s the sound speed, and v_± the fast and slow magnetosonic speed.