A strong atmospheric river storm system impacted the state of California in the USA from 10 March 2023, with heavy rain, snow, isolated thunderstorms and gusty winds reported. Thousands of residents were placed under Evacuation Orders and 2 storm-related fatalities have been reported.
On 08 March, California Governor Gavin Newsom declared a state of emergency in 21 counties: Butte, El Dorado, Fresno, Humboldt, Imperial, Inyo, Lake, Mendocino, Merced, Monterey, Napa, Placer, Plumas, Sacramento, San Francisco, San Mateo, Santa Clara, Santa Cruz, Stanislaus, Tuolumne and Yuba. This was in addition to several counties declared previously and puts 34 of California’s 58 counties under a state of emergency.
“California is deploying every tool we have to protect communities from the relentless and deadly storms battering our state,” said Governor Newsom. “In these dangerous and challenging conditions, it is crucial that Californians remain vigilant and follow all guidance from local emergency responders.”
The National Weather Service and the Federal Emergency Management Agency (FEMA) warned of flash, urban, and small stream flooding, minor to moderate river flooding, and shallow mudslides or debris flows on burn scars. FEMA said 80,221 structures and 292,359 people were potentially exposed.
California’s Office of Emergency Services said on 10 March that 2 storm-related fatalities were confirmed and approximately 9,400 residents were under evacuation orders. Around 54,000 people were without power, in particular in the county of Monterey, where 18,000 were affected.
Residents have evacuated their homes in several parts of Tulare County, including Springfield, after rivers broke their banks. Evacuation orders were also issued for residents in San Luis Obispo County and also in Santa Cruz County due to high levels of the San Lorenzo River.
Firefighters and teams from the National Guard rescued dozens of people from flood waters in Monterey County after a levee on the Pajaro River failed on 11 March. Emergency teams also rescued people from flooded homes in Fresno County.
FEMA reported multiple closures of major ground transportation routes across the state. Hundreds of residents in Soquel in Santa Cruz County were isolated after flooding wiped out the one road connecting the community to the rest of the region.
The storm system is one of a number of such weather systems to hit California since late 2022. The California Department of Forestry and Fire Protection (CALFIRE) said it has responded to nearly 100,000 incidents since 01 January 2023, including clearing debris, responding to calls for help, and providing emergency support to affected communities. The daily average exceeds 1,450 calls per day, CALFIRE said.
— The California National Guard (@CalGuard) March 11, 2023
Mandatory Evacuation orders issued for the Community of #Pajaro due to a #LeveeBreak. Please heed evac warnings/orders. Pajaro River levee broke early this morning resulting in active flooding. #Evacuate if told. #TurnAroundDontDrown @Cal_OES @CaltransHQ @CAgovernor pic.twitter.com/tDttiTcaC0
— California Governor’s Office of Emergency Services (@Cal_OES) March 11, 2023