California Declares Grid Emergency as Storm Delivers Rain

(Bloomberg) -- California declared a power-grid emergency for a fifth day Friday as rain from a tropical storm along Mexico’s Pacific Coast headed north, delivering relief from sweltering temperatures but increasing concerns about the power supply.

The California Independent System Operator, or Caiso, declared a level-1 emergency, warning the state could have insufficient power supplies later in the day. It asked customers to conserve energy from 4 p.m. to 9 p.m. 

Clouds from the storm have combined with smoke from a wildfire raging in the Sierra Nevada foothills to cut production to the state’s solar power plants. The amount of electricity they generate could drop 40% to 60% compared to earlier in the week, Caiso warned.

“We need to stay very focused for one more day,” said Elliot Mainzer, Caiso’s chief executive officer, in a press briefing Friday. “But hopefully by tomorrow, we’ll start seeing a change, a significant reduction in our loads.”

Meanwhile, heavy rain started to fall across Southern California. As much as 4 inches (10 centimeters) could fall, with some areas getting up to 8 inches, the US National Hurricane Center said in an intermediate advisory at 11 a.m. Pacific time.

While the storm’s center won’t make landfall in the Golden State, its rain and clouds will drop a curtain on the lingering heat.

In addition, the storm brings high winds that could topple tree limbs, knocking down power lines and raising risks of outages and fires in a drought-stricken region that has endured record-breaking temperatures since late August.

“Much of the heat is going to give way through the weekend,” said Frank Pereira, a senior branch forecaster at the US Weather Prediction Center. “Today is really the last of the worst of it for much of California.”

Kay will help to knock down temperatures though it’ll raise the risk of flooding in the mountains and deserts of southern California, Pereira said.

As much as 5 to 7 inches of rain could fall in the mountains east of San Diego, while the city itself gets close to an inch, the National Weather Service said. Along with the rain, gusty winds up to 50 miles per hour (80 kilometers per hour) could sweep across southern California and western Arizona.

By 10:30 a.m. Friday, the temperature had reached 89 Fahrenheit (31.6 Celsius) under cloudy skies in Sacramento with the forecast calling for a high of 107 later, which would be a degree shy of a record for the date, according to the National Weather Service. It was 91 in Fresno, which also has a forecast high of 107, and 90 in Modesto, which could reach 104.

Excessive heat warnings are still out for a large part of California’s Central Valley, but they are set to expire at 8 p.m. Until then residents are being urged to avoid strenuous activity and to turn to air conditioning to cool down.

(Updates throughout)

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