摘要：This paper examines the severity and extent of flooding caused by six predecessor rain events (PREs) over the Midwest United States. PREs are areas of heavy rainfall that occur about 1000 km ahead of landfalling tropical cyclones. While recent studies have mostly focused on the synoptic conditions associated with PREs, little is known about the hydrologic impacts of these events. Here, we use discharge data collected by the US Geological Survey to perform flood analyses at the regional scale. We first examine the number of stations at which a PRE caused an annual maximum flood peak. We then compute the flood ratio, defined as the ratio between the flood peak magnitude caused by the PRE and the at-site, expected 10 year flood peak magnitude. These results indicate that PREs are responsible for significant flooding over the Midwest United States, including highly populated areas like Chicago, Illinois and Detroit, Michigan.
