Over 40,000 Californians ordered to evacuate, amid deadly, relentless coastal storms

More than 40,000 Californians have been ordered to evacuate and roughly 90% of the entire state population is under flood watches due to excessive rain from a relentless coastal storm pattern known as "atmospheric rivers."

The severe weather is expected to continue until Thursday, according to the National Weather Service.

Atmospheric rivers, described by the National Oceanic and Atmospheric Administration as "relatively long, narrow regions in the atmosphere – like rivers in the sky – that transport most of the water vapor outside of the tropics," are pummeling the state, causing more than 34 million Californians to be under flood watch. 

About 32,000 residents of Santa Cruz County were ordered to evacuate on Monday, according to the Associated Press. The county has since lifted the order but kept a flood warning in place.

In Santa Barbara County, about 10,000 people received evacuation orders, including in the entire town of Montecito, which is home to celebrities such as Prince Harry and Oprah Winfrey. The order was sent on the fifth anniversary of a deadly mudslide that destroyed over 100 homes and killed 23 people in the coastal city.

A sinkhole in Santa Barbara County resulted in additional evacuations. 

A 5-year-old boy is missing from the flooding near Paso Robles. The child's mother became stranded while driving Monday morning, and while bystanders were able to rescue her, the boy was swept away, Cal Fire/San Luis Obispo County Fire Department Assistant Chief Tom Swanson said.

The child has not been declared dead, but only his shoe has been found after a seven-hour search that was called off because it became too dangerous.