Atmospheric rivers made visible by clouds, the ribbons of water vapor known as atmospheric rivers can extend thousands of miles from the tropics to the western USA. They provide the fuel for the massive rainstorms and subsequent floods along the U.S. West Coast. The one that’s fueling the storms this week stretches some 5,000 miles, all the way from Asia. Though beneficial for water supplies in the western USA, these events can wreak havoc on travel, bring deadly mudslides and cause catastrophic damage to life and property, the National Oceanic and Atmospheric Administration said.

Article from USA Today, October 19, 2017

https://www.usatoday.com/story/weather/2017/10/18/5-000-mile-long-river-sky-deliver-heavy-rain-feet-snow-northwest/776060001/