Powerful atmospheric river triggers state of emergency in Southern California, rare Level 4 of 4 risk of excessive rainfallAn intense atmospheric river event hit California on Sunday, February 4, 2024, prompting Gov. Gavin Newsom to declare a state of emergency in eight counties due to the potential for “life-threatening” flooding, mudslides, and widespread power outages. The National Weather Service warns of significant rainfall, powerful winds, and heavy snowfall continuing over the next few days.
An intense, slow-moving atmospheric river that arrived in California on Sunday, February 4, 2024, has unleashed a series of severe weather phenomena across the state, including “life-threatening” flooding, mudslides, and widespread power outages.
This event has prompted Governor Gavin Newsom to declare a state of emergency in Los Angeles, Orange, Riverside, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, and Ventura counties.
The National Weather Service (NWS) in Oxnard has highlighted the situation as one of the most dramatic weather days in recent memory, with a rare Level 4 of 4 risk of excessive rainfall announced for parts of Southern California, including Los Angeles, Santa Barbara, and Oxnard. This warning predicts rainfall rates of up to 25 mm (1 inch) per hour, resulting in total rainfall amounts of 76 to 152 mm (3 to 6 inches) across the affected areas.
The situation has led to significant disruptions, including the closure of Santa Barbara Airport due to flooding and the rescue of 19 people off Long Beach after their boat’s mast broke in high winds.
In Northern California, fallen trees and power lines have caused injuries and power outages, with over 800 000 customers currently without electricity.
The weather conditions have also impacted travel, with the NWS issuing its first-ever hurricane-force wind warning for San Francisco, forecasting winds of 64 to 97 km/h (40 to 60 mph) with gusts up to 153 km/h (95 mph) in the foothills and mountains. This has made travel in the mountains, particularly above elevations of 1 500 to 1 800 meters (5 000 to 6 000 feet), near impossible due to heavy snowfall and whiteout conditions.