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Nationwide patterns of severe events provide crucial data for hazard response and mitigation

An understanding of the relationship between severe weather and power outages in our changing climate will be critical for hazard response plans, according to a study led by a researcher at Columbia University Mailman School of Public Health. The study is published in the open-access journal .

Throughout the U.S., large-scale power outages commonly occur alongside severe weather events. These combined events can be associated with major economic costs and health risks, as loss of power can disrupt medical equipment, heating or air conditioning, and other important systems.

As severe weather events increase in severity and frequency due to climate change, understanding the patterns and distribution of these outages is critical for community preparation and resource allocation.

In this study, first author Vivian Do, a Ph.D. candidate in environmental health sciences, and colleagues compiled data from 2018–2020 on severe weather events (including rain, snow, heat, cold, cyclones, and wildfire) and large-scale power outages lasting eight hours or more for over 1,600 counties across the country.

The data reveal that nearly 75% of these counties experienced major power outages alongside severe weather events during this three-year period, and over 50% of counties experienced outages alongside multiple simultaneous weather events.

Outages most commonly occurred alongside severe precipitation and heat, but the events are not distributed evenly, with precipitation-associated outages more common in the Northeast U.S. and heat-associated outages more common in the Southeast. This study also found that co-occurring outages and wildfires along the West Coast became increasingly common from 2018 to 2020.

The researchers note that reliable data was not available for all U.S. counties, so information is limited in regions such as the Southwest and Mountain West. Do and colleagues suggest that further research providing additional data, along with simulations of severe weather combinations in different locations will be useful for developing mitigation and response tactics.

Do adds, "Power outages frequently co-occur with severe weather events like heavy precipitation, tropical cyclones, or multiple severe weather events simultaneously. Understanding patterns of where and when power outages and severe weather events co-occur is crucial for informing strategies to minimize societal consequences, especially as the electrical grid ages and climate change drives more severe weather events."