Pacific Gas & Electric Co. officials started alerting over 200,000 customer accounts in 16 counties in Northern California that their power might be preemptively shut off later this week, less than two weeks after it shut off power to millions of people to help prevent wildfires. PG&E said the reason for this week’s potential shutoff is high fire threats caused by windy conditions, combined with dry grasses and large numbers of dead and dying trees. “We see some hot and windy weather coming into our service area, but we have not made the call yet,” PG&E spokeswoman Megan McFarland told the San Francisco Chronicle. “Forecasters are looking at weather models every hour to see what’s happening. We will make the call when we’re ready.” PG&E officials said decisions to shut off power near the Sierra foothills and the North Bay will be made about about 5 p.m. on Wednesday evening, and a San Mateo County shutoff would likely happen at about 2 a.m. Thursday morning.