Statistical significance of tropical cyclone forward speed on storm
surge generation: retrospective analysis of best track and tidal data in
Japan
Abstract
In this study, 42 years of tidal records and landfall TC best tracks in
Japan were used to demonstrate that TC pre-landfall forward speed is
significantly correlated with maximum storm surge height. Coastal
morphology was the determining factor for the correlation between storm
surge and TC forward speed. 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). 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 (TC)
operational forecasts are continuously improving; however, there is
still scope to improve the precision of storm surge predictions. These
findings could contribute to the improvement of storm surge forecasting
and provide emergency management personnel with more precise early
warnings of dangerous storm surges.