California floods: State of emergency declared and warnings issued about an aerial river
US authorities today renewed their urgent warnings to residents of Southern California about the imminent dangers of widespread flooding and dangerously high river levels. This comes as a result of a wave of torrential rains battering the region, which is not expected to subside during the holiday season, prompting the declaration of a state of emergency in Los Angeles and much of the South.
The phenomenon of "air river" and its climatic impact
The US National Weather Service explained that the state is experiencing what is scientifically known as an "atmospheric river," a narrow corridor in the atmosphere that transports enormous quantities of water vapor from the tropics. This weather phenomenon is capable of producing heavy rainfall over short periods, placing immense pressure on infrastructure and drainage systems, and increasing the likelihood of flash floods in both urban and rural areas.
Risk of landslides in areas of previous fires
In its warnings, the agency emphasized the potential for “dangerous and potentially fatal flash floods,” issuing a particular alert for areas previously affected by wildfires. These areas are considered most vulnerable, as the soil has become fragile and unable to absorb water, leading to the formation of mudflows and debris flows that can sweep away homes and vehicles at high speed—a recurring and tragic scenario in the state’s history of natural disasters.
Declaration of Emergency and Official Response
In response to these rapidly evolving developments, California Governor Gavin Newsom declared a state of emergency in several counties, including the densely populated Los Angeles County. This measure aims to mobilize state resources, facilitate potential evacuations, and expedite the delivery of federal and local aid to those affected, amid concerns about travel disruptions during the holiday season.
Historical context and weather fluctuations
These storms are part of a volatile weather pattern California has experienced in recent years, oscillating between years of severe drought and years of record rainfall. While this rain helps replenish groundwater reservoirs and dams, its sudden intensity often causes significant economic and human losses, highlighting the ongoing challenges that climate change poses to the US West Coast.
