Western Wildfires are Making Far Away Storms More Dangerous

In late July of 2018, massive wildfires blazed across Northern California. At the same time in Colorado, weather alerts went out warning of heavy thunderstorms and baseball-sized hail. The two disasters were separated by a thousand miles, but scientists are now finding they’re connected.

The massive clouds of smoke and heat that rise out of Western wildfires are having far-reaching effects across the country, even beyond hazy skies. That summer, the smoke blew to the Central U.S., where it ran headlong into summertime thunderstorms that were already forming.

The collision made those storms even more extreme, boosting the rainfall and hail by more than 30 percent, according to a new study in the Proceedings of the National Academy of Sciences.

"It’s surprising to many people, probably," says Jiwen Fan, Laboratory Fellow at the Department of Energy’s Pacific Northwest National Laboratory and an author of the study. "I really wanted to look at if there’s any connections between them."

Understanding the effects of wildfires on weather patterns far downstream could help improve forecasts in those areas. In the Central U.S., extreme summer storms can pose a dangerous threat, often doing millions of dollars in damage.