Pacific Gas and Electric is considering shutting off power to about 11,150 customers in five Bay Area counties as dry offshore winds raise wildfire concerns, the utility said Tuesday. The possible Public Safety Power Shutoff could affect roughly 70,000 customers across 29 counties and last until Saturday afternoon. The estimated Bay Area impacts are 4,705 customers in Alameda County, 1,605 in Contra Costa County, 3,027 in Napa County, 30 in Solano County and 1,783 in Sonoma County. PG&E said the strongest winds are expected in the Sierra, the southern Central Coast and parts of the North and East Bay. Diablo winds are forecast to peak Thursday across the northern and central Sierra and portions of the North and East Bay. The utility cited extremely dry vegetation and relative humidity expected to fall into the single digits and teens in many areas. The shutoff is intended to reduce wildfire risk from energized power lines, but would leave affected households without electricity if enacted. PG&E began sending notices by text, email and automated phone calls Monday, about two days before a potential shutoff. The company expanded the possible outage area Tuesday and sent additional notices. About 4,000 customers affected by shutoffs earlier in the week may be affected again, while roughly 5,700 customers initially included have since been removed from the potential scope. PG&E said newer, higher-resolution weather modeling is helping it narrow the areas under consideration. The utility also plans, when possible, to visit customers enrolled in its Medical Baseline Program who have not confirmed receipt of safety notices, prioritizing people who depend on electricity for life-sustaining medical equipment. Customers can check whether an address is being monitored for a possible shutoff at pge.com/pspsupdates. PG&E’s forecast page has further information about the potential outage.