Variations in floods associated with Tropical Cyclones over Mexico under ENSO conditions

Tropical cyclones (TCs) are among the most hazardous hydrometeorological phenomena. Mexico is affected by TCs from the North Atlantic and Eastern Pacific oceans, and they originate 86.5% of domestic disasters. The natural hazards associated with TCs are extreme precipitation events, floods, storm surges, and landslides. In the present preliminary study, we focus on exploring how El Niño-Southern Oscillation (ENSO) modulates the frequency and magnitude of extreme precipitation events and floods caused by TCs. We use the CHIRPS dataset for determining the extreme precipitation events (defined by the 95^th percentile of daily precipitation) and Mexican rain gauge stations from May to November during the 1981-2013 period. We find that TCs are responsible for ~60% of floods in coastal regions, but this percentage decreases inland. Under El Niño conditions, most floods occur over southwestern Mexico. During neutral conditions, the western coast of Mexico is mainly affected. Under La Niña conditions, most floods occur over the eastern coast of Mexico. Additionally, trends in floods are explored. We conclude that local decision-makers need this information to decrease the hydrometeorological risk before the tropical cyclone season begins. Implementing this information on Early Warning Systems for TCs is also discussed.