El Niño and El Niño Modoki impacts on extreme precipitation in the U.S.
Intense precipitation events lasting from 1 to 24 hours can lead to major flooding with serious social, economic, and environmental impacts. Many factors affect the development of weather patterns conducive to extreme precipitation in the U.S., including changes to the climate system brought on by warming of the eastern or central Pacific Ocean waters, known as El Niño and El Niño Modoki, respectively. Forest Service researchers worked with colleagues at Michigan State University to investigate the similarities and differences in the patterns of warm-season (May-October) and cold-season (November-April) sub-daily extreme precipitation occurrences across the U.S. during El Niño and El Niño Modoki episodes that occurred over the 1979-2013 period. Results from the study suggest there are significant regional differences in the occurrences of extreme precipitation in the U.S. during El Niño and El Niño Modoki episodes, with cold-season extreme precipitation occurrences being more strongly associated with El Niño than El Niño Modoki episodes. Understanding when and where extreme precipitation and associated flooding could occur in the U.S. in response to El Niño or El Niño Modoki episodes can aid in the development of emergency management and environmental plans for responding to and mitigating the effects of damaging floods.
Forest Service Partners