The two hurricanes that walloped the southeast recently—Helene and Milton—caused extensive damage and loss of life, with Helene becoming the second-deadliest hurricane in the last 30 years. Although thousands of miles away, these two hurricanes serve as reminders about flood management in California. … California storms can be just as intense and destructive as hurricanes. Although hurricanes are not part of California’s natural disaster portfolio, people sometimes forget that California has its own equivalent in atmospheric rivers (ARs). These storms—which often carry as much water as the Amazon River up in the atmosphere—originate in the subtropical Pacific Ocean and deliver prodigious amounts of rain and snow to California. Although ARs do not pack the high-speed winds of hurricanes, their precipitation intensities match what we’ve seen in Helene and Milton.