Rivers in the sky causing widespread chaos in California

Rivers in the sky causing widespread chaos in California

Doyle Rice , USA TODAY Published 1:08 p.m. ET Feb. 20, 2017 | Updated 1 hour ago

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Central and Northern California are prepping for more intense storms. Heavy rain could lead to flooding and mudslides. Several feet of snow is expected to fall in the mountains. WUSA

(Photo: NOAA)

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Yes, there are rivers up in the sky, and they're responsible for up to 65% of the western USA's extreme rain and snow events, a new study released Monday found.
Made visible by clouds, these ribbons of water vapor known as atmospheric rivers extend thousands of miles from the tropics to the western U.S. They provide the fuel for the massive rainstorms and subsequent floods along the U.S. West Coast, such as the one that's blasting northern California on Monday.
The study, which appeared in the peer-reviewed British journal Nature Geoscience, said that it's not only the U.S. that sees these weather troublemakers: Globally, up to 75% of extreme precipitation events come from atmospheric rivers, said study lead author Duane Waliser, an atmospheric scientist at NASA's Jet Propulsion Laboratory.
In western Canada, northern Europe, New Zealand and southern South America, atmospheric rivers occur on about 30 to 35 days per year, Waliser said.
While beneficial for the water supplies in the western U.S., these events can wreak havoc on travel, bring deadly mudslides and cause catastrophic damage to life and property, the National Oceanic and Atmospheric Administration said.

One well-known nickname for an atmospheric river is the "Pineapple Express," which occurs when the source of the moisture is near Hawaii.  A single strong atmospheric river can transport up to 15 times the water vapor compared to the average flow of water at the mouth of the Mississippi River, according to NOAA's Earth System Research Laboratory.
This winter has been especially active for atmospheric rivers in the West, said meteorologist Jeff Zimmerman of the National Weather Service, with as many as 10 separate rivers identified.  On average, Northern California gets five to seven atmospheric rivers per wet season, the weather service said
The onslaught has knocked out the five-year drought in northern California, with much of the Sierra Nevada seeing its rainiest and snowiest October-February period on record, the weather service said.
While their influence on rain and snow has been studied before, one surprising new finding from the study is that up to 75% of extreme wind events in the western U.S. are due to atmospheric rivers.
And in Europe, of the 19 windstorms that each did at least a billion U.S. dollars in damage there from 1979 to 2003, 14 of those storms were due to damage from atmospheric rivers, Waliser said​.
Contributing: KXTV-TV, Sacramento, Calif.