What is a climatic stream?

.FOR CALIFORNIANS it believed that remembrance. In 2015 a procession of tornados, fuelled by atmospherical streams, killed a minimum of 21 people as well as created almost $5bn-worth of damage across the condition. On February 4th this year the same form of tornado once more created chaos.

Hurricane-strength winds buffeted the central coast near Huge Sur. In Los Angeles celebs were soaked as they reached the Grammy awards’ welcome mat. Manors in the Hollywood Hills were actually covered in dirt.

A minimum of three individuals have perished. What are actually atmospherical streams, and are they a danger past California?