Tidal currents and western boundary currents play an important role in the shelf-break/slope (SBS) transition, where processes occurring at a variety of temporal and spatial scales can interact enhancing biological productivity. In the southwestern tropical Atlantic (SWTA), the North Brazil Undercurrent (NBUC), was previously reported to induce uplift along the slope. In this work we investigated the high frequency temporal and spatial-scales of the shallow (15-59 m) along- and cross-shelf velocities in a SBS transition in the SWTA. The data was obtained from the Multiple Rectangles Transect (MRT) experiment, where continuous (every 2 min) measurements of currents were made crossing the shelf-break repeatedly during a timeframe of 26 hours. The variability was analyzed through adaptative signal analysis methods, and we investigated if the observed patterns contributed to uplift variability on a short timeframe from hydrographic profiles. Results showed that tidal forcing was the main responsible for the variability of the along- and cross-shelf currents in different scales. Cross-shelf patterns of divergence/convergence during flood/ebb, expected from the tidal forcing, were amplified or reduced by the effect of stronger or weaker along-shelf current on the slope; and flood timing for cross-shelf flow was coherent with uplifted waters reaching the shelf-edge stations. Local variability of uplift intensity was related to tidal forcing added to the currents of the NBUC’s upper limit. While there was no stronger uplift during the high tide (in relation to climatologic patterns), the decrease of the along-shelf velocity during low tide, resulted in decrease of uplift. Therefore, tidal forcing appears as an important process to be considered in uplift mechanisms for the western boundary system in question. Still, more investigation is needed, since our dataset was limited and there are open questions about SBS dynamics enhancing productivity in the SWTA.