SAN FRANCISCO (CBS SF) — Extremely dry and windy conditions have prompted Pacific Gas and Electric to issue a 48-hour notice Monday of a potential Public Safety Power Shutoff affecting 303,000 customers in 25 Northern California counties, including six Bay Area counties.

The high-fire risk conditions are expected to begin early Wednesday morning through Thursday, according to forecasters. More than 100,000 customers will potentially lose power in Alameda, Contra Costa, Marin, Napa, Solano and Sonoma counties, according to PG&E, with most of the possible outages centered in the North Bay.

At 9 p.m. Monday, PG&E added 39,000 customers in portions of Santa Cruz, Santa Clara and San Mateo counties to the list of those potentially affected, based on the changing weather forecast.

PG&E Potential Public Safey Power Shutoffs, 11/18 update (Click to enlarge)*Note: the chart above does not reflect the addition of Santa Cruz, San Mateo and Santa Clara counties. 

PG&E said customers can use an online address lookup tool to find out if their location is being monitored for the potential safety shutoff at

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The National Weather Service said Sunday that winds should begin to increase overnight Tuesday, spreading southward over the higher elevations of the North Bay and East Bay around sunrise Wednesday. These north-northeast winds will reach 20 to 30 mph with gusts of 35 to 45 mph expected; local gusts at isolated peaks and ridgetops may approach and possibly exceed 60 mph.

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Those winds, combined with humidity readings expected to drop during the day on Wednesday to 10 to 20 percent (and to single-digit percentages in some localized spots), are expected to combine for the kind of fire hazard that prompted a series of PG&E power shutoffs in late October all over the Bay Area, Sierra foothills and other parts of the state.

PG&E said once the high winds subside, crews would inspect the de-energized lines for possible damage during the wind event, before power would be restored in stages.

The utility said it hoped to have all customers back up by end of day Thursday, based on the current weather conditions.

Updates to the possible public safety power shutoffs would be issued again 24 hours prior and again four hours prior, according to PG&E. The utility also said customers who have provided their contact information to PG&E will be notified by phone, text and email.

PG&E said it is setting up Community Resource Centers where customers will be provided snacks, ice, blankets, restroom facilities and charging stations. More information can be found at