Influence of ENSO on Landfalling Tropical Cyclone Hazards in Coastal United States

Tropical cyclone (TC) climatological features, such as genesis location and track density, are found being modulated by El Nino and Southern Oscillation (ENSO) in previous research. However, how ENSO influences the hazards related to landfalling TCs on coastal United States has not been discussed.

In this research, we evaluate impacts of ENSO signal on coastal hazards related to US landfalling TCs. A statistical-dynamical synthetic storm model and the Princeton environment-dependent probabilistic tropical Cyclone (PepC) model are employed to downscale the reanalysis data to generate a large number of TCs for the US coast. The simulated TCs in both models are coupled with physics-based storm surge, TC rainfall, and TC wind models to simulate corresponding hazards associated with the synthetic storms. The climate variability of landfalling synthetic storms are compared and evaluated against observations, and evaluation of hazard variability are performed for selected sites. The marginal and joint probability features of the hazards along US coastlines are analyzed in different ENSO conditions to investigate how ENSO impacts the hazards. For various landfalling locations, we examine the change in hazard return levels in difference ENSO conditions from a joint-hazard perspective. Preliminary results show that the TC hazard in South Coast of the United States has stronger variability than in the East coast. The differences of the hazard levels simulated by the two synthetic storm models will be discussed as uncertainty sources.