.FOR CALIFORNIANS it thought that familiarity. In 2014 a march of tornados, sustained through climatic rivers, killed at least 21 folks as well as induced virtually $5bn-worth of harm across the condition. On February fourth this year the very same form of storm again wreaked havoc. Hurricane-strength winds buffeted the core shore near Large Sur. In Los Angeles stars were saturated as they arrived at the Grammy honors' red carpet. Mansion houses in the Hollywood Hills were dealt with in dirt. At least three people have actually died. What are atmospherical waterways, and are they a risk beyond The golden state?