RT Journal Article SR Electronic T1 Atmospheric rivers drive flood damages in the western United States JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaax4631 DO 10.1126/sciadv.aax4631 VO 5 IS 12 A1 Corringham, Thomas W. A1 Ralph, F. Martin A1 Gershunov, Alexander A1 Cayan, Daniel R. A1 Talbot, Cary A. YR 2019 UL http://advances.sciencemag.org/content/5/12/eaax4631.abstract AB Atmospheric rivers (ARs) are extratropical storms that produce extreme precipitation on the west coasts of the world’s major landmasses. In the United States, ARs cause significant flooding, yet their economic impacts have not been quantified. Here, using 40 years of data from the National Flood Insurance Program, we show that ARs are the primary drivers of flood damages in the western United States. Using a recently developed AR scale, which varies from category 1 to 5, we find that flood damages increase exponentially with AR intensity and duration: Each increase in category corresponds to a roughly 10-fold increase in damages. Category 4 and 5 ARs cause median damages in the tens and hundreds of millions of dollars, respectively. Rising population, increased development, and climate change are expected to worsen the risk of AR-driven flood damage in future decades.