PG&E confirmed this morning (Oct. 23) that it will move forward with another fire danger-related power shutoff that will impact parts of San Mateo County, including Woodside, beginning at 1 a.m. Thursday.

The shutoff is expected to affect 372 customers in Woodside, La Honda, San Gregorio and unincorporated San Mateo County and approximately 179,000 customers overall in 17 counties.

Woodside Town Manager Kevin Bryant said Wednesday afternoon that most of the households in town that will lose power are near the Highway 84 and Skyline Boulevard intersection.

Late Tuesday evening, PG&E removed Portola Valley from its list of San Mateo County communities that could lose power. Redwood City, Emerald Hills and parts of the Coastside were also originally listed as communities that could be impacted.

"Forecasts indicate the peak period of winds should end about noon Thursday in the Sierra Foothills, North Bay and San Mateo County," the utility said in a press release. "Once the high winds subside, PG&E will inspect the de-energized lines to ensure they were not damaged during the wind event, and then restore power. PG&E will safely restore power in stages as quickly as possible, with the goal of restoring the vast majority of customers within 48 hours after the weather has passed."

PG&E added that power in San Mateo County should not take long to restore because of the low number of customers affected.

The utility had initially said Monday afternoon that nearly 6,500 customers throughout the county and about 209,000 in 15 counties could lose power. The countywide figure dropped to 907 customers Tuesday morning. PG&E cited changing weather conditions and being able to sectionalize certain power lines in reducing the number of customers that might lose power from 209,000 to 179,000.

Just short of 15,000 customers in San Mateo County lost power during a planned shutoff earlier this month, and those in Portola Valley and Woodside who lost power then generally had it restored within about 24 hours.

PG&E President and CEO William Johnson said the company has set up a sister website where customers can determine whether their power will be shut off. That website is at psps.ss.pge.com/.

The announcement is in response to a dry, offshore wind event, PG&E officials said. The shutoff is intended to reduce the risk of catastrophic wildfire ignitions from its energized power lines that could fall during inclement weather.

Customers were notified by text and automated phone calls Monday afternoon, and PG&E said an employee will knock on the doors of customers with medical issues who are enrolled in its Medical Baseline program.

PG&E officials said they will focus their efforts on those customers who need electricity for life sustaining equipment.

The officials said its meteorological and operations teams' models show wind gusts may exceed 55 mph late Wednesday evening through Thursday afternoon for portions of the Sierra Foothills. Winds between 35 and 45 mph with some 55 mph gusts in localized areas are forecast for Sonoma and Napa counties.

Similar weather patterns prompted PG&E to proactively shut off power for hundreds of thousands of customers starting on Oct. 9. Many streets in Portola Valley and Woodside lost power in that shutoff, and schools in the Portola Valley Elementary School District were closed Oct. 10 as a result.

There are no mandatory circumstances under which PG&E will take action to shut off power to a given area, but possibilities include a "red flag warning" declared by the National Weather Service; humidity levels of 20% and below; predicted sustained winds generally above 25 mph and wind gusts of 45 mph; conditions with dry fuel on the ground and live vegetation; and on-site observations from PG&E field crews, according to utility spokeswoman Andrea Menniti.

PG&E announced earlier this year that it was starting the public safety power shutoff program as a precautionary measure during windy and dry conditions. The utility has faced harsh scrutiny for its role in the devastating wildfires in Northern California in the last two years.

Weekend shutoff?

PG&E's website also predicts the potential for power shutoffs for the upcoming week in various regions of its service area.

The website currently indicates an elevated potential for a power shutoff in San Mateo County this Sunday and Monday. According to the utility, that means "an upcoming event (a period of gusty winds, dry conditions, heightened risk) is being monitored for an increased potential of a Public Safety Power Shutoff (PSPS) event."

"Another offshore wind event is then possible Sunday into Monday and may impact locations generally north of Monterey to Yosemite line," PG&E said Wednesday. "Details around this event remain unclear, but it has the potential to be as strong or stronger than recent events. In addition, dead fuel moistures will decrease significantly in the first event today and tomorrow, setting the stage to be critically dry and very susceptible to fire for the weekend event."

Almanac reporter Angela Swartz and Bay City News Service contributed to this report.