(Photo : David McNew/Getty Images) SUN VALLEY, CA - FEBRUARY 17: A man boards a bus on a flooded street as a powerful storm moves across Southern California on February 17, 2017 near Sun Valley, California. After years of severe drought, heavy winter rains have come to the state, and with them, the issuance of flash flood watches in Santa Barbara, Ventura and Los Angeles counties, and the evacuation of hundreds of residents from Duarte, California for fear of flash flooding from areas denuded by a wildfire last year.

An “Atmospheric-river” is a thin region of moisture in the atmosphere that flow through storms. A recent research on atmospheric river reveals that it can cause most dangerous rainfall and extreme winds. An atmospheric river can hold 15 times more water than the amount of water flows through the Mississipi river at a time.

This winter, a percent of California that was soaked by the drought, ended up by The atmospheric river. A team of atmospheric scientists led by Dr.Duane Waliser has found that atmospheric rivers are responsible for about 75 percent of all heavy rainfall and extreme winds.

To gather more information, Dr. Waliser studied two decades of storm data around the planet that were outside the tropics. He found that 30 to 50 percent of all cases of extreme storms are associated with atmospheric rivers. His research result was first published in the journal of Nature Geoscience.

An atmospheric scientist at NASA's Jet Propulsion Laboratory and lead researcher of this study, Dr. Duane Waliser said in a statement,“Not only atmospheric rivers come with this potential for flooding hazards, they also come with potential for high impact winds and extremes that can produce hazardous conditions”. he also explained that atmospheric rivers are responsible for very wettest storms too.

According to Science Alert, winds during an atmospheric river are typical twice the speed of the average storm. On Jan. 8 when the last atmospheric river hit California, knocked down the famous iconic Sequoia 'Tunnel Tree'.

western Canada, New Zealand, Northern Europe, and southern South America are the highly affected zones in the globe, atmospheric rivers occur almost 35 days in a year. Between 1979 and 2003, almost 19 most damaging and expensive storms happened in Europe and 14 of them were linked to atmospheric river activity. Waliser explained that his next plan is to find out if climate change will make atmospheric rivers more frequent.