Californians are used to facing climatic extremes – usually heat waves, wildfires and droughts. February 2024. has, however, brought residents of Los Angeles and surrounding areas a new cause for concern, after heavy rains flooded roads and left more than half a million people without power. According to meteorologists, this is just the beginning of a series of water disasters. A catastrophic flood of biblical proportions is a scenario that must begin to be taken seriously, experts warn.
What are atmospheric rivers? The catastrophic flood of 1862.
In meteorology, an atmospheric river is a long and relatively narrow strip of water vapor that forms over the ocean and travels inland. It transports huge amounts of moisture from tropical zones to the north, bringing abundant rainfall to slightly cooler regions. The phenomenon is occurring in various parts of the world, but is particularly acutely manifested on the west coast of the United States. The catastrophic flood that hit California, Oregon and Nevada in 1862. was the result of the passage of a whole series of atmospheric rivers over two winter months. The death toll at the time was approx. 4 thousand. People, and 25 percent. cattle drowned. Losses were estimated at $100 million. – The equivalent of today’s 3 billion.
Wet February in California
In early February this year. Strong atmospheric rivers have come over the west coast of the United States. According to the National Weather Service (NWS), the three-day rainfall total was second highest observed since 1877, the beginning of meteorological data collection. In California, the balance of five days of heavy rainfall brought more than 500 mudslides and nine deaths. Local flooding affected Los Angeles and Santa Barbara County, and even mountainous areas of Santa Ynez.
Flood risks have affected up to 40 million residents, of which 11 million have been identified as life-threatening. Representatives of Pacific Gas&Electric, one of the region’s largest energy suppliers, announced that they had never before recorded so many power outages during a single storm – at one point up to 1.4 million of their customers were without electricity. In San Francisco Bay, wind gusts reached up to 126 km/h, knocking down coastal trees and electric poles.
Catastrophic flooding is only a matter of time?
According to experts, the dramatic events of early February will continue and intensify. In 2022. Daniel Swain and Xingying Huang, scientists at the National Center for Atmospheric Research in Colorado, have published an analysis that says another catastrophic flood is a real and growing threat to California. Accumulated satellite data suggests that climate change has already doubled the risk of cataclysmic events, and in black scenarios, rainfall totals in future storms could be as high as 200-400 percent. higher than historical records for the Sierra Nevada.
Scientists recalled the disastrous flood of 1862. and suggested that tragedies of this magnitude occur ca. 7 times per millennium, or roughly every 100-200 years. Meanwhile, 150. The anniversary of the cataclysm is upon us. In 2010. The U.S. Geological Survey, in cooperation with a multidisciplinary team of scientists, has prepared a flood scenario dubbed ARkStorm 1.0, which anticipates the need to displace millions of people and close important transportation corridors, with total economic losses estimated at nearly $1 trillion.
Projections provided by Swain and Huang in 2022. is an update to the pessimistic scenario, referred to as ARkStorm 2.0. Although the California Department of Water Resources (DWR) was involved in its preparation, the work is underfunded and still in its infancy.
California unprepared for dangers
Dr. Daniel Swain, who has become California’s favorite social media meteorologist in recent years, warns that inadequacies in cooperation between federal and state agencies make it difficult to properly prepare for black scenarios. So far, flood control infrastructure has been strengthened mainly in the US Midwest, where water hazards have historically been a priority. In California, its shortages are significant, as highlighted, for example, by the intense increase in gastrointestinal infections after the recent floods in the San Diego region.
The catastrophic flooding predicted by scientists will be a far greater threat to life, public health, infrastructure and the functioning of society than any before. Without adequate investment and good communication with citizens, its effects will be dramatic.