California is facing the strongest storm of 2018, coming on something called an “atmospheric river” or a “pineapple express.” Here’s an explainer. A strong atmospheric river can carry 7½ to 15 times the average flow of liquid water at the Mississippi River’s mouth. A pineapple express is a particular kind of strong atmospheric river. Most of California’s major historical floods have come from slow-moving or stalled atmospheric rivers, Swain wrote. 6 p.m.: This article was updated to include information on how much water vapor is contained in a strong atmospheric river.

Source: Los Angeles Times March 21, 2018 20:03 UTC