FORECASTING MULTI-HAZARD SCENARIOS WITH ENSEMBLE TROPICAL CYCLONE FORECASTS

Multi-hazard events resulting from tropical cyclones (TC) involve the simultaneous or sequential occurrence of various destructive disasters, including storm surges, heavy rainfall, and strong winds, which collectively pose significant threats to society (Needham et al., 2015; Takagi et al., 2022). While ensemble forecasts are widely employed in TC prediction, their potential for comprehensively assessing multi-hazard scenarios has been ignored (Titley et al., 2019). In this study, we introduce Pareto optimization based an innovative, efficient, and practical framework for analyzing multi-hazard scenarios, utilizing large ensemble TC forecasts comprising 1000 members to evaluate storm surge, rainfall, and wind-related risks. To exemplify the applicability of our approach, we conducted simulations for TC Hagibis that hit Central Japan in 2019 using the non- hydrostatic model from the Japan Meteorological Agency (JMA). The resulting atmospheric predictions served as inputs for modeling storm surges, rainfall patterns, and wind hazards. We anticipate that this assessment framework will empower forecasters, disaster management authorities, and communities to make well-informed decisions and enhance their resilience in the face of TC-related impacts.