.FOR CALIFORNIANS it felt like remembrance. In 2014 a procession of hurricanes, sustained by atmospheric streams, killed at least 21 folks as well as triggered almost $5bn-worth of damages all over the state. On February fourth this year the exact same form of hurricane once more ravaged. Hurricane-strength winds buffeted the central coastline near Big Sur. In Los Angeles celebs were saturated as they arrived at the Grammy honors' red carpet. Mansion houses in the Hollywood Hillsides were actually covered in mud. At least three people have died. What are atmospheric waterways, and are they a risk beyond California?