The processes of vortex formation and spin-down due to secondary (Ekman) motions have been studied in the field near an inlet and in the laboratory. The nonbuoyant tidal discharge issuing from an estuary into the coastal ocean was investigated during spring tides in January 1984. Surface drogue tracks showed that after an initial phase of development the outflow structure consisted of a pair of vortices propagating away from the inlet ahead of a jet region. The vortex velocity structure was well represented by a Rankine vortex with a small Ekman-suction-induced radial velocity. To investigate the effect of the initial conditions on the flow development, a series of laboratory experiments was conducted in which the source flow acceleration was varied while other parameters were held constant. Vortex spin-up due to shear layer roll-up is compensated by spin-down due to Ekman suction, and eventually the outflow structure becomes independent of the initial conditions. It is shown that during the initial phase the vortex radius and the azimuthal and radial velocities within the vortex depend on source flow acceleration. ¿ American Geophysical Union 1990