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Publication Date
6 October 2023

Real-Time Attribution of the Influence of Climate Change on Extreme Weather Events: A Storyline Case Study of Hurricane Ian Rainfall

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Ensemble average 3-day accumulated rainfall in inches (in) for the Hurricane Ian for CAM forecasts initialized on September 27, 2022 at 12Z for the (a) counterfactual and (b) actual ensembles.
Science

As the Earth continues to warm due to human greenhouse gas emissions, there is a growing need to efficiently communicate the effect that global warming has on individual extreme weather events. Using a storyline approach, we present a rapid attribution of the increase in rainfall over Florida during Hurricane Ian in 2022 due to climate change as a case study.

Impact

Using a previously developed and tested hindcast attribution methodology applied to the 2020 Atlantic Hurricane season, we demonstrated in near real-time that storyline rapid assessments of individual tropical cyclones can be completed during an event. Such rapid assessment offers scientists a useful tool in answering questions about the climate change effect on individual extreme weather events as they unfold.

Summary

We find that extreme accumulated rainfall amounts associated with Hurricane Ian increased by 18%, far in excess of what would be expected by Clausius-Clapeyron scaling. The storyline approach offers a blueprint for rapid operational climate change attribution statements about extreme storms and other very rare weather events.

Point of Contact
Michael Wehner
Institution(s)
Lawrence Berkeley National Laboratory (LBNL) - Applied Mathematics and Computational Research Division
Funding Program Area(s)
Publication