Forecast Triple-Digit Heat Brings Weekend Red-Flag Fire Warning, Possible Preventive Outages
SAN FRANCISCO (CBS SF) -- A weekend weather system will send temperatures soaring, humidity levels dropping and stir up bone-dry, hot northeastern winds, triggering a Red Flag fire warning across wildfire-ravaged Northern California and an alert from Pacific Gas & Electric of possible preventative power blackouts.
The National Weather Service said the Red Flag warning will go into effect at 9 p.m. Saturday and end at 8 a.m. Monday.
"East winds will come off the Sierra they will make a beeline towards Mt Diablo and the North Bay," NWS forecasters said. "Again there will be no humidity recovery Sunday night and the models show east winds driving all the way to the coast and offshore."
"Any fires that develop will spread rapidly in the hot, dry and windy weather," forecasters added.
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Napa County authorities also said local residents to remain aware of the changing conditions. They said the greatest threat was to the hills of northeast Sonoma County and Napa County above 1,000 feet.
"Strongest winds (will be) near Mount Saint Helena as well as Mount Tamalpais in Marin County," the warning read. "Persistent offshore winds will reach all the way to the coast Sunday night so coastal Sonoma County including the Wallbridge and Woodward fire in Point Reyes will feel the effects of the drying offshore winds."
Parts of the East Bay around Mount Diablo and the East Bay hills of Oakland and Berkeley as well as the interior valleys along the I-680 corridor, I-580 east of the Altamont and the Highway 4 corridor will also be impacted.
The withering northerly and easterly winds are common in the fall and historically signaled the arrival of fire season in California. But the fires have come early this year as the state has already seen more than 8,000 wildfires scorch 5,600 square miles.
"We've already had three fire seasons in one year," said Cal Fire spokeswoman Lynne Tolmachoff.
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Most of the loss has occurred since Aug. 15, when remnants of Tropical Storm Fausto off Mexico surged up the coast and unleashed thousands of dry lightning strikes that ignited massive complexes of multiple fires around the San Francisco Bay Area.
Those and subsequent conflagrations in the Sierra Nevada and elsewhere have left 26 people dead and destroyed more than 6,700 homes and other structures, according to Cal Fire.
Helicopters with "Bambi Buckets" to douse flames will be gassed up and ready to go this weekend.
More than 17,000 firefighters are still battling wildfires burning across California. Shifting and relocating crews from the Central Valley and Southern California is now part of the continuous and high-stakes game against Mother Nature.
"We're looking to move some resources from other parts of the state, where the fire risk is a little bit less, up here to Northern California," said Daniel Berlant with Cal Fire.
That's why the last two strike teams from the Contra Costa Fire Protection District battling various lightning complex fires over the last month just returned home Thursday night, officials said.
"Those crews that are returning are well rested and everyone else is rested and morale is high," said Steve Hill with the Contra Costa County Fire Protection District.
With no growth expected in the CZU, SCU, and LNU wildfires, Cal Fire said only about a dozen firefighters remain working at each of those nearly 100 percent contained fires to put out hot-spots, doing mop-up duty and completing fire suppression work.
"That allows us to really make sure we're focused heavily on resources in the Bay Area and in Northern California," said Berlant. "We're constantly monitoring the conditions and moving fire resources around the state as those weather conditions dictate."
What will help crews across the Bay Area this weekend, is a fairly new fire program called "pre-positioning."
"Pre-positioning is a program that allows us -- with state funding -- to stand up additional fire fighting apparatus, engines, and Crews ahead of red-flag weather," said Hill.
The possibility of wildfire smoke returning to the region also prompted an Air Quality Advisory for the Bay Area.
The Bay Area Air Quality Management District issued the advisory for Friday, as smoke from the August Complex Fire burning in the Mendocino National Forest is expected to drift into the North Bay and parts of the East Bay, causing hazy skies. The advisory was later expanded to Saturday.
Officials stressed that AQI levels are expected to remain in the good to moderate range, but officials said they would continue to monitor air quality throughout the region. A Spare the Air alert was not issued.
The latest round of threatening weather triggered a warning Thursday night from PG&E that households may lose electricity this weekend as a result of Public Safety Power Shutoffs.
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"We now have a PSPS Watch," PG&E spokesperson Tamar Sarkissian said in a release. "A PSPS Watch indicates that PG&E has activated our Emergency Operations Center as there is a reasonable chance of executing a PSPS for public safety in a given geographic zone due to a combination of adverse weather and dry fuel conditions."
Currently, very few San Francisco Bay Area customers appeared to be in the potential shutoff zones, with approximately 200 customers in the Napa County area.
Planned shutoffs will primarily impact customers in the Sierra and northeastern California. Approximately 97,000 customers in portions of Alpine, Amador, Butte, Calaveras, El Dorado, Kern, Lake, Nevada, Placer, Plumas, Shasta, Sierra, Tehama and Yuba counties are being notified of possible service impacts.
The utility's emergency website provides a clearer visual of where the shutoffs will take place.
Kenny Choi contributed to this story.