Map of Sierra Nevada in California showing how an atmospheric river develops. Most atmospheric rivers are weak and do not cause damage. In fact, they can provide much-needed rain or snow.

In the 1860s, California had to move its capital out of Sacramento because of an atmospheric river flooding. These events aren't just a California thing. They actually happen all over the United ...

Here's an explanation of how they form, their size and potential impacts. WHAT IS AN ATMOSPHERIC RIVER? The weather system occurs all over the world. It starts when a large amount of water vapor ...