Strong, dry winds across large areas of Northern and Central California may prompt PG&E to turn off power across 30 counties, including San Mateo County, on Wednesday and Thursday.
Customers in seven of the Bay Area's nine counties could be affected, including those in San Mateo, Santa Clara, Alameda, Contra Costa, Napa, Santa Cruz and Sonoma counties, according to PG&E.
Starting Wednesday morning and persisting through Thursday afternoon, the dry and windy weather is expected to hit the northern end of PG&E's service area, then spread into Central California and the Bay Area.
The National Weather Service has called a Fire Weather Watch Tuesday night through Thursday, including parts of the North and East Bay as well as the Santa Cruz Mountains.
Forecasters say it's likely to be the strongest offshore wind event of the 2019 fire season.
PG&E is asking customers to get ready by updating their contact information so they can be notified when electrical service powers down and gets restored, and to plan ahead for any medical needs that require refrigeration or devices that need electricity to run.
Anyone using a backup generator to get through the shutoff is advised to be aware that generators pose unusual hazards not typically associated with grid power. People should make sure to vent the generator's exhaust outside to prevent carbon monoxide poisoning, and avoid running portable generators in the garage.