The temporal evolution of a flow reversal during upwelling conditions along New Jersey's inner shelf is characterized with shipboard, moored, and remote observations. The flow reversal occurs nearshore in the form of a subsurface jet with maximum velocities exceeding 30 cm/s. The jet is most intense in the thermocline, commences during maximum alongshore wind stress, and has a spin-up time approximately equal to the local inertial period. The jet also has a surface signature apparent in ocean current radar data that shows the jet veering offshore and feeding an upwelling center that drifts southward at 5 cm/s. Moored instrumentation within the upwelling center indicates that cross-shelf transport in the warm surface layer is consistent with the predicted Ekman transport prior to the spin-up of the jet, but exceeds Ekman transport thereafter. However, onshore transport in the lower layer never compensates for offshore flow in the surface layer, suggestive that the mass balance requires a three-dimensional closure. Finally, we suggest that the flow reversal provides a significant fraction of cool water to the evolving upwelling center, and that the offshore veering is due to enhanced friction over a shoaling and rougher topography.