Correlating Storm Surge Heights with Tropical Cyclone Winds at and before Landfall

This paper investigates relationships between storm surge heights and tropical cyclone wind speeds at 3-hour increments preceding landfall. A unique dataset containing hourly tropical cyclone position and wind speed is used in conjunction with a comprehensive storm surge dataset that provides maximum water levels for 189 surge events along the U.S. Gulf Coast from 1880-2011. A landfall/ surge classification was developed for analyzing the relationship between surge magnitudes and pre-landfall winds. Ten of the landfall/surge event types provided useable data, producing 117 wind/ surge events that were incorporated into this study. Statistical analysis indicates that storm surge heights correlate better with pre-landfall tropical cyclone winds than with wind speeds at landfall. Wind speeds 18 hours before landfall correlated best with surge heights. Raising wind speeds to exponential powers produced the best wind/ surge fit. Higher wind/ surge correlations were found when testing a more recent sample of data that contained 63 wind/ surge events since 1960. The highest correlation for these data were found when wind speeds 18 hours before landfall were raised to a power of 2.2, which provided R-squared values that approached 0.70. R-squared values at landfall for these same data were only 0.44. Such results will be useful to storm surge modelers, coastal scientists and emergency management personnel, especially when tropical cyclones rapidly strengthen or weaken while approaching the coast.