The term “atmospheric river” has bubbled up in the news again, as California braces for the possibility of significant precipitation this weekend.

What are atmospheric rivers, and how has California been affected by them in the past? Here are a few graphics from the Scientific American archive to get you up to speed. Check out “The Coming Megafloods” by Michael Dettinger and B. Lynn Ingram in the January 2013 issue for more context. 

 
Credit: Don Foley
 
Credit: Jen Christiansen (graphic), XNR Productions (map)