California’s Climate Has Come Unmoored
The weather of catastrophe is here.
An atmospheric river is exactly what it sounds like: a ribbon of concentrated moisture that can stretch for 1,000 miles through the sky. The one that brought all manner of chaos to Los Angeles this week formed when water vapor rose from the sea’s surface somewhere east of Hawaii. As the planet turned, it got caught in a narrow channel between pinwheeling pressure systems. Strong winds pushed it east, until it came to hover like a snake over Southern California. Think of its tail as having sections. Mountains and pressure systems popped some up into the colder parts of the atmosphere, and the droplets in them cooled until they fell
