Mixed population of extreme precipitation in the eastern United States: The role of North Atlantic tropical cyclopes

North Atlantic tropical cyclones are the major physical process contributing to the mixed population distribution of extreme precipitation in the eastern United States. Despite the recognized importance of properly identifying the physical processes that generate extreme precipitation among mixed populations to obtain more accurate precipitation frequency estimates, the topic has received little attention. We used the long-term precipitation records over the period of 1951–2020 for 667 United States Historical Climatology Network stations across the eastern United States to: i) systematically characterize the mixtures in the daily precipitation extremes by separating the tropical cyclone precipitation and non- tropical cyclone precipitation, and ii) model tropical cyclone precipitation and non- tropical cyclone precipitation as mixed population that weight the individual extreme event-generating phenomenon appropriately. Results from our study are important for proper characterization of extreme value distribution for prediction and attribution of extreme events in a changing climate, as well as implications for improved design and reassessment of flood-controlling infrastructure.