Trepanier, J.C.; Needham, H.F., and Ellis, K.N., 2018. Understanding the influence of tropical cyclone landfall central pressure and accumulated rainfall on storm surge near New Orleans, Louisiana.
Tropical cyclone track, landfall central pressure, accumulated cyclone rain, and storm surge are assessed for five stations surrounding Lake Pontchartrain in Louisiana: Shell Beach, the New Orleans Lakefront, Frenier, Mandeville, and Slidell. Floods from 1901–2012 are analyzed for cases in which the event tracks, the landfall central pressure, the amount of inland flooding from precipitation, and the storm-surge inundation all lead to compound effects, as in Hurricane Katrina (2005) and Hurricane Isaac (2012). Data are from U-Surge, the National Hurricane Center, and the National Weather Service Cooperative Observer Program. A storm track climatology is provided showing the average track for all events and for events that reached at least 43 m s−1. The intense storms have a more concentrated track and approach from the south. Correlation and multivariate linear regression were used to evaluate the relationship among landfall central pressure, accumulated rainfall, and storm surge. For every 1 mbar increase in pressure when rainfall was held constant, the storm surge decreased by 0.024 m (p value <0.000). For every 1 mm of increase in rainfall when pressure was held constant, the storm surge increased by 0.006 m (0.0001). These two variables explain 63% of the variability in storm surge at this station. A percentage of change analysis from quantile regression was used to understand the amount of change in the storm surge based on the amount of change in the rainfall or the landfall central pressure. A small change in rainfall amounts or landfall central pressure can lead to a large change in the storm surge.