On Thursday, forces in California were starting to converge as wildfires endangered towns, an extreme heat wave taxed the power infrastructure, and rain from a tropical cyclone was anticipated to bring thunderstorms and flooding in addition to cooling.
Major wildfires in Southern California and the Sierra Nevada have prompted significant evacuations, developed explosively, and created smoke that might interfere with the generation of solar electricity. Firefighters have fought to contain these flames.
About 30 square miles of Riverside County were burned by the Fairview Fire in Southern California, which had just 5% containment. On Monday, two individuals perished attempting to escape the flames, and at least seven buildings have been destroyed.
In the Sierra, the Mosquito Fire burned out of control, scorching at least 11 square miles, forcing evacuations for some 2,500 residents in Placer and El Dorado counties, while blanketing the region in smoke.
Flames jumped the American River, burning structures in the mountain hamlet of Volcanoville and moving closer to the town of Foresthill, home to about 1,500 people. Fire spokesperson Chris Vestal called the fast-moving blaze an “extreme and critical fire threat.”
The Nevada Division of Environmental Protection warned the Reno area that air quality could be very unhealthy to hazardous due to smoke from the Mosquito Fire 100 miles away.
The fire’s cause remained under investigation. Pacific Gas & Electric notified the state Public Utilities Commission that the U.S. Forest Service placed caution tape around the base of a PG&E transmission pole but that no damage could be seen. PG&E said unspecified “electrical activity” occurred close in time to the report of the fire on Sept. 6.
Another dangerous blaze burned in stands of timber near the Big Bear Lake resort region in the San Bernardino Mountains east of Los Angeles. It was just 2% contained after scorching nearly 2 square miles.
A surge of clouds and showers associated with Tropical Storm Kay off Mexico’s Baja California peninsula knocked the edge off temperatures in Southern California at times but also were a potential problem for solar generation. The storm was downgraded from a hurricane Thursday evening.
Despite the initial impacts of Kay, forecasters warned that the heat was not yet done.
“The seemingly endless heat wave that has been plaguing California will finally becoming to an end across at least Southern California, but not before two more very hot days and very warm nights,” the Los Angeles-area weather office wrote.
Operators of California’s power grid issued another “Flex Alert” call for voluntary cuts in use of electricity and expanded the period by two hours, 3 p.m. to 10 p.m.
Wildfire smoke and the cloud cover created uncertainty about solar power production in afternoon hours when temperatures rise toward their peaks, said Elliot Mainzer, president and CEO of the California Independent System Operator.
There was also uncertainty about wind power at the back end of the period.
Cal-ISO has issued Flex Alerts since last week and has avoided ordering rolling power outages, although a miscommunication with one Northern California provider led to blackouts.
With record demand on power supplies across the West, California snapped its record energy use around 5 p.m. Tuesday with 52,061 megawatts, far above the previous high of 50,270 megawatts set July 24, 2006.
An emergency appeal for conservation that was sent to Californians’ cellphones was credited with an immediate drop in demand on the electrical grid that evening.
Electrical demand hit 50,184 megawatts on Wednesday but it ended up being “a relatively quiet operation on the system,” Mainzer told a briefing.
The electrical load forecast for Thursday afternoon and evening was higher, however, and the uncertainty involving the renewable energy sources made the situation a bit more complex, he said.
“We certainly think we’re close to turning the corner, but we still have challenges ahead of us this evening,” Mainzer said.
He warned that the storm and wind conditions brought on by the impending hurricane were probably going to bring up a new set of dangers for Southern California’s power outages.
The National Weather Service predicted that Tropical Storm Kay will make landfall in northern Baja California on Friday. Kay was anticipated to unleash a wave of precipitation across Southern California while losing hurricane status. Flash floods, gusty gusts, and heavy rain were all possible from Friday evening into Saturday. Mariners were given notice of tropical storm warnings.
After an unusually hot and dry late summer, forecasters along the West Coast anticipated strong, gusty winds and low humidity over western Oregon starting on Friday. They also warned of a higher risk of wildfires.
In anticipation of high, dry winds that pose a significant wildfire risk in the area, an Oregon utility said it would cut power to around 12,500 customers to the south and west of Portland immediately after midnight on Friday. According to another company, some 30,000 more customers may also experience power outages in an effort to put out fires caused by sagging or damaged electrical lines.
Fire bans were also implemented by towns and communities across western Oregon and southwest Washington, including Seaside, where even beach bonfires were forbidden.
Although “rapid fire spread” was predicted, forecasters noted that winds were not anticipated to be as strong as those that struck over Labor Day weekend in 2020 and sparked wildfires that consumed more than 1 million acres, damaged 4,000 houses, and claimed the lives of at least 11 people.