Dependency of U.S. Hurricane Economic Loss on Maximum Wind Speed and Storm Size

Many empirical hurricane loss models consider only wind speed and neglect storm size. Such models may not accurately predict the losses from super-sized storms such as Hurricane Sandy in 2012. In this study, the dependency of normalized U.S. hurricane loss on maximum wind speed and storm size is examined for 73 tropical cyclones that made landfall in the U.S. from 1988 to 2012. The multi-variate regression is used to construct a hurricane loss model with wind speed and size as predictors. It is found that normalized hurricane loss (L) approximately follows a power law relation with maximum wind speed (V) and size (R), with L =cV^aR^b and c being a scaling factor. The coefficients, a and b, generally increase with increasing storm intensity. For all tropical cyclones of at least tropical storm intensity (73 cases), a and b are 4.2 and 1.3, respectively. For Category 1 and above hurricanes (43 cases), a and b are 5.0 and 2.7, respectively. For major hurricanes of Category 3 and above (15 cases), a and b are and 12.0 and 4.4, respectively. Using both maximum wind speed and size capture more variance of hurricane losses than using wind speed or size alone. For Hurricane Sandy, its size was about 3 times of the average size for the 43 hurricanes. Such an enormous size would cause a loss about 20 times of that from an averaged sized hurricane with the same wind speed.