Science Inventory

Informing Future Risks of Record‐Level Rainfall in the United States

Citation:

Informing Future Risks of Record‐Level Rainfall in the United States. GEOPHYSICAL RESEARCH LETTERS. American Geophysical Union, Washington, DC, 46, (2019). https://doi.org/10.1029/2019GL082362

Impact/Purpose:

In this study, we build on such approaches and use spatially clustered precipitation data to provide information on changing risk of extreme precipitation on a more useful scale for regional risk analysis and adaptation. Using this spatial clustering approach, we seek to characterize the magnitude of extremely rare (1 in 1000 years) historical precipitation events in each of 15 regions in the continental United States, as well as the changing probability of those events under a range of warming scenarios.

Description:

The changing risk of extreme precipitation is difficult to project. Events are rare by definition, and return periods of heavy precipitation events are often calculated assuming a stationary climate. Furthermore, ensembles of climate model projections are not large enough to fully categorize the tails of the distribution. To address this, we cluster the contiguous United States into self‐similar hydroclimates to estimate changes in the expected frequency of extremely rare events under scenarios of global mean temperature change. We find that, although there is some regional variation, record events are projected in general to become more intense, with 500‐year events intensifying by 10–50% under 2 °C of warming and by 40–100% under 4 °C of warming. This analysis could provide information to inform regional prioritization of resources to improve the resilience of U.S. infrastructure.