The US state of California has battened down the hatches as a hurricane threatens the coast.

California governor Gavin Newsom (pic) proclaimed a state of emergency for much of Southern California in an effort to organise support for the arrival of Hurricane Hilary, which was downgraded to a category one event as it barrelled through Northern Mexico heading towards the Southern United States.

Newsom said the declaration had been made to support the response and recovery efforts as the state continues mobilising and coordinating resources ahead of the storm’s forecasted impacts starting today.

Hurricane Hilary is expected to bring “catastrophic and life-threatening flooding” to Baja California and the Southwestern US, including Southern California, warned the National Hurricane Centre. Much of the impacts of the storm, including heavy rainfall and high winds, are expected to and last throughout the rest of Monday.

The Governor signed the emergency proclamation in San Diego while visiting with California National Guard troops.

Newsom said: “California has thousands of people on the ground working hand-in-hand with federal and local personnel to support communities in Hurricane Hilary’s path with resources, equipment and expertise. We’re mobilizing all of government as we prepare and respond to this unprecedented storm.”

“We’re closely monitoring incoming impacts from rain, wind, and potential flash flooding and power outage due to Hurricane Hilary which is now a Category 4 storm. The State Operations Centre at Cal OES is currently activated in response to multiple, overlapping emergencies.”

Some parts of Southern California could receive a year’s worth of rain from this storm.

A California state spokesperson added: “We’re working closely with the National Hurricane Centre, National Weather Service and county emergency officials in the areas of the state that are in the path of the storm. The State Operations Centre is actively coordinating across state agencies to provide resources in preparation for potential impacts and to support response and recovery efforts.”

As Hilary moves across the U.S.-Mexico border today, the worst of its wind and rain appeared to be aimed at inland areas, including mountains and deserts, as well as parts of Imperial, Riverside and San Bernardino counties.

Mountains from the border to the San Bernardino range, as well as desert cities such as Palm Springs and Coachella, were under a flood watch through today amid fears of flash flooding.

Janice Hahn, chair of the Los Angeles county board of supervisors said that the threat was one she never thought would be faced by the city or the state.

“I don’t think any of us – I know me particularly – never thought I’d be standing here talking about a hurricane or a tropical storm,” she said.

Speaking from Camp David US president Joe Biden urged the population to listen to the state and federal advice.
“I urge everyone, everyone in the path of this storm, to take precautions and listen to the guidance of state and local officials,” he said.