What is an atmospherical river?

.FOR CALIFORNIANS it felt like remembrance. In 2014 a procession of tornados, sustained by climatic waterways, eliminated at least 21 individuals and created virtually $5bn-worth of damage around the condition. On February fourth this year the same sort of tornado once more created chaos.

Hurricane-strength winds buffeted the main shore near Large Sur. In Los Angeles stars were actually saturated as they arrived at the Grammy honors’ welcome mat. Mansion houses in the Hollywood Hillsides were actually dealt with in dirt.

At least three people have actually perished. What are actually climatic waterways, and are they a danger beyond The golden state?