California has been literally flooded with water since last weekend. On Sunday, more rain fell in the US state on the Pacific coast than in around 20 years, reports the television station CNN. There are TV images of raging floods, houses destroyed by mudslides, fallen trees and cars driving through flooded streets. Anyone who doesn’t necessarily have to go out should currently stay indoors, the authorities warn.
A state of emergency was declared for a number of districts. According to American media, three people died in the storm. Power outages affected hundreds of thousands of households, it said.
A phenomenon called “atmospheric river” is responsible for the weather chaos. The German Weather Service describes this as a “long and narrow corridor with strong horizontal water vapor transport”. A lot of moisture-saturated air is therefore transported in a relatively limited band. The result is extreme rainfall in the affected areas. The weather phenomenon is about 500 kilometers wide, but is around 2,000 kilometers long or even longer, writes the dpa.
The “Pineapple Express” brings a lot of water from the tropics to California
Such systems transported much of the water vapor outside the tropics. Because the moist air masses that hit California mostly come from the tropical ocean regions in the Pacific region around Hawaii, they are also called the “Pineapple Express.”
Meteorologists expected heavy rainfall for southern California until Tuesday. Such extreme and destructive rainfall is unusual for the US state.
Experts warn that such extreme weather phenomena are becoming more common as global warming occurs. The western United States suffered from a heat wave in the summer. The following winter was unusually wet.
Sources: CNN, ABC News, German Weather Service / with material from dpa and AFP