Californians have been the victims of multiple atmospheric rivers recently. This week’s violent storm fueled by an atmospheric river caused flooding over a wide area in various portions of the state.
Hillsides were transformed into rivers of mud and rocks. And more than a half-million people were left without electricity statewide as of Monday.
What exactly is an atmospheric river? It’s a long and relatively narrow corridor of water vapor that forms over the Pacific Ocean. As it moves over land, it can produce enormous amounts of rain or snow. And California got it all this weekend…
Torrential Downpours Produce Flooding, Mudslides
A flash flood warning was in effect for approximately 1.4 million people in the Los Angeles area. Including Beverly Hills and Hollywood Hills.
Officials declared evacuation orders in some areas as nearly a foot of rain fell in a short amount of time… With more anticipated. On Sunday, 4.1 inches of rain fell in downtown Los Angeles. It nearly doubled the previous record of 2.55 inches in one day, which occurred 96 years ago.
The National Weather Service called the flash flooding and threat of mudslides “a particularly dangerous situation.” Evacuations occurred in mountain and canyon areas of Monterey, Santa Barbara, Ventura, and Los Angeles counties.
Northern California was also hit hard. Streets were flooded, and trees and electrical wires were downed. The area saw wind gusts of over 80 miles per hour.
Winds. Floods. Snow… ‘We’ve Had the Whole Gamut Here’
Residents had to be pulled from their vehicles by rescuers. Another rescue involved a homeless encampment near a rising river.
One man in Yuba City was killed when a large redwood tree fell in his backyard Sunday night. This was 100 miles northeast of San Francisco.
Todd Hall is a meteorologist with the National Weather Service. He said, “We’ve had flooding. We’ve had gusty winds. We’ve had the whole gamut here.
“I’ve been doing damage reports all night, so I’ve seen a fair amount of damage and of people being evacuated from homes due to mudslides.”
‘Pineapple Express’ Not as Sweet as It Sounds
At higher elevations, the storm produced heavy snow. Two feet of the white stuff was expected through the Sierra Nevada. People were warned to avoid mountain roads.
This was the second storm powered by an atmospheric river in less than a week. This one was called a “Pineapple Express.” That’s due to its moisture stretching all the way back to Hawaii.
As the latest atmospheric river moved in, those living on the central coast of California were warned of “hurricane-force wind” by the weather service. Including gusts of more than 90 mph.
State of Emergency Declared in 8 Counties
California Governor Gavin Newsom declared a state of emergency in eight counties. They are Los Angeles, Orange, Riverside, and San Bernardino. As well as San Diego, San Luis Obispo, Santa Barbara, and Ventura.
Moderate to heavy rainfall was expected to continue falling on Southern California through Tuesday. Mainly because the system stalled over the area on Monday.
Some coastal and valley areas, as well as foothills and mountain areas, were expected to receive eight to 14 inches of rain.
A number of school districts in the state closed schools on Monday. Shelters were opened for those ordered to evacuate.
More – and More Powerful – Storms Ahead
Atmospheric rivers are not new. Actually, they’re not even rare.
The Scripps Institution of Oceanography’s Center for Western Weather and Water Extremes says 46 of them made landfall on the U.S. West Coast last year. Nine of them were categorized as “strong,” two as “extreme,” and one as “exceptional.”
In fact, California is dependent upon atmospheric rivers to provide between 30 and 50% of their annual precipitation. For a state that has seen more than its share of drought, they can be a welcome visitor…
But when they are powerful and slow moving, they bring torrential downpours that result in flooding and mudslides. Atmospheric rivers are typically between 250 and 375 miles in width. They are greatly influenced by other weather patterns.
According to the U.S. Geological Survey, an atmospheric river can carry between seven and 15 times the average amount of water that is discharged daily by the Mississippi River.
Weather experts predict more frequent, larger, and wetter atmospheric rivers in the future. Californians can’t stop atmospheric rivers, or the damage and power outages caused by them. All they can do is prepare.
