As Pacific Gas & Electric Co. moved forward with a public safety power shutoff Wednesday, the California Independent System Operator called for a statewide Flex Alert on Thursday, warning that high temperatures could force further outages.
The alert will run from 3 to 10 p.m., the ISO said in a news release. Consumers are being urged to conserve electricity, especially during the late afternoon and early evening, when the grid is most stressed due to higher demand and falling solar production.
PG&E on Wednesday evening started de-energizing electrical lines in response to forecasted hot, dry and windy conditions. The PSPS is expected to affect up to 53,000 customers in targeted portions of 24 counties, including thousands in the Bay Area.
The National Weather Service has issued heat and wind advisories, as well as a red flag warning for much of the region. Inland areas are expected to see temperatures in the upper 90s to low 100s, or 15 to 25 degrees above normal. At the same time, elevations ranging from 1,000 to 2,500 feet are forecast to see 10 to 20 mph winds with 35 to 40 mph gusts. Gusts up to 55 mph are possible at the highest mountain peaks.
The winds will dry fuels and lower humidity levels to below 20 percent, according to the weather service.
“Fuels are very dry and we continue to trend drier through this event,” said PG&E senior meteorologist Scott Strenfel. “By tomorrow afternoon, we do expect relative humidities for this event to fall into the teens to single digits. So with the dry fuels and the further drying, those fuels are going to be very vulnerable to new fire ignitions.”
The weather service said the heat advisory will run from 11 a.m. Thursday to 9 p.m. Friday and the wind advisory will run from 10 p.m. Wednesday through 11 a.m. Thursday. The red flag warning took effect at 5 a.m. Wednesday and will run through 11 a.m. Friday.
The power shutoff is scheduled to occur in three phases. The first phase, which began at 6 p.m. Wednesday, was expected to affect some 33,000 customers in the counties of Butte, Lake, Napa, Nevada, Plumas, Shasta, Solano, Sonoma, Tehama, Yolo and Yuba. The second phase was scheduled to begin at 8 p.m. Wednesday and affect 19,000 customers in the counties of Alameda, Amador, Calaveras, Contra Costa, El Dorado, Monterey, Nevada, Placer, San Mateo, Santa Clara, Santa Cruz and Sierra. The third phase will begin at 4 p.m. Thursday and affect 700 customers in Humboldt and Trinity counties.
The utility is aiming to restore service to most customers by 10 p.m. Friday, said Mark Quinlan, senior director of emergency preparedness and response for PG&E. After a PSPS, crews will examine power lines and equipment in the area to look for any damage before re-energizing.
PG&E begins Bay Area public safety power outages, with Diablo winds looming
Source:: The Mercury News – Entertainment