We've been getting soaked lately. A series of torrential rainstorms often called the "Pineapple Express" has been bringing flooding to Vancouver Island and parts of the Lower Mainland.
Hardest hit has been drought-stricken California. Unfortunately these squalls can do far more harm than good. This isn't the sort of precip California needs.
This graphic, depicting the past 72-hours, shows the atmospheric river coming out of the central Pacific to the North American coast. They call it an atmospheric river because it delivers precip equivalent to 15 times the flow of the Mississippi.
A report in Scientific American explains how these atmospheric rivers can be devastating - and deadly:
In 1861 an atmospheric river that brought storms for 43 days turned California’s Central Valley into an inland sea 300 miles long and 20 miles wide. Thousands of people died, 800,000 cattle drowned and the state went bankrupt. A similar disaster today would be much more devastating, because the region is much more populated and it is the single largest food producer in the U.S.