San Francisco, Mar 16 (IANS): In the wake of the storm system that hammered California throughout the week, the San Francisco Bay Area has suffered the worst power outage in almost three decades.

An atmospheric river arrived in Northern California Tuesday morning, bringing heavy rains and high wind throughout the San Francisco Bay Area, reports Xinhua news agency.

The Pacific Gas & Electric Co. (PG&E) said on Wednesday that some 450,000 customers were affected and at its peak, 367,000 were without power, according to PG&E.

By Wednesday noon, about 80,000 customers in the South Bay and 35,000 on the Peninsula were still lacking electricity.

Sumeet Singh, the company's vice president of operations and chief operating officer, said that Tuesday brought the 13th major storm event of the season, calling it "the most impactful storm that we have seen in terms of customers out in a single day in the Bay Area, since 1995".

In the Santa Cruz Mountains, gusts hit 97 mph on Tuesday.

The downed trees toppled many power lines, and 5,500 PG&E personnel were on the ground in restoration efforts Wednesday, according to PG&E Vice President of Emergency Preparedness and Response Angie Gibson.

California Governor Gavin Newsom expanded a state of emergency to cover 43 of the state's 58 counties as high winds and intense rain wrought havoc in the state.

Some cities endured hurricane-force winds and top wind gusts of 97 mph were measured at Santa Clara County's Loma Prieta, 93 mph at Alameda County's Mines Tower and 74 mph at San Francisco Airport, according to the National Weather Service.