Over the past several decades, scientists have focused on numerical sensitivity analysis to explain the relative importance of tropical cyclone (TC) forward speed on storm surge and wave height predictions. These past studies performed numerical analyses, but the results have not been sufficiently compared with long term observations. In this study, 42 years of tidal records and landfall TC best tracks in Japan were analyzed, demonstrating that TC pre-landfall forward speed is significantly correlated with both maximum storm surge and significant wave height. Coastal horizontal morphology was the determining factor among these correlations. Fast-moving TCs tended to amplify the storm surge along open coastlines (Pearson correlation coefficient, R = 0.62), but reduce it in semi-enclosed bays (R = -0.52). A similar tendency has also been observed for the case of wave height (open coast, R = 0.62; bay, R = -0.52). The negative correlation contrasts with the general perception that the coincidence of TC wind speed and forward speed vectors generates a larger storm surge. The influence of coastal morphology was most prominent for TCs with a central pressure lower than 956 hPa. Tropical cyclone operational forecasts are continuously improving; however, there is still scope to improve the precision of storm surge - wave predictions. These findings may be beneficial in two main areas. Firstly, considering TC transitional speed and coastal geometry (open coastline or bays) - meteorologists and oceanographers could provide more comprehensive surge-wave forecasts, and emergency management personnel could use pre-landfall forward speed for more precise early warning. Secondly, coastal areas at risk with no access to advanced weather forecasting could use these empirical findings along with other TC intensity related information (e.g., wind speed, central pressure, radius) for improvement of early-warning activities.