Fires lead governor to declare emergency

SAN FRANCISCO — Gov. Gavin Newsom declared an emergency Tuesday over wildfires burning throughout California amid excessive heat as the state’s power grid operator pleaded with residents and businesses to continue conserving energy to avoid rolling blackouts.

“We’re in a critical 48-hour period, critical period this evening, and we’re doing everything in our power to understand the root causes of this,” he said.

The state is in a dayslong heatwave that has stressed the electrical system and resulted in rolling blackouts over two nights last weekend. The strong ridge of high pressure responsible for the heat wave was expected to weaken, but excessive hot weather was forecast for the weekend. Crews were battling some 30 large fires across the state, some sparked by lightning.

Earlier Tuesday, Steve Berberich, president and CEO of the California Independent System Operator, had praised customers for astonishing conservation efforts that kept the power on Monday night.

“I know it’s hot, and I know it’s hard, but those same actions today can make all the difference in the world,” he said.

California ISO issued the first rolling blackouts in nearly 20 years on Friday, turning off power to more than 410,000 homes and businesses for about an hour at a time until the emergency declaration ended 3 ½ hours later. A second, shorter, outage hit Saturday evening, affecting more than 200,000 customers.