Ball moving below the critical speed. Symmetrical Flow.

The extent of the boundary layer, and the general form of the turbulent wake behind the ball. The wake is slightly broader than the ball, and the pressure on it immediately behind the ball is lower than on the front part of the ball (It is the net effect of the pressure on the whole surface that retards the ball). The wake gradually melts back into the undisturbed air.

(The drawing is not to scale : the thickness of the boundary layer is exaggerated in order to show it.)