Pacific Gas & Electric warned that it was likely to cut power temporarily to almost 200,000 customers in Northern California by Wednesday night, the second pre-emptive blackout in two weeks.

A growing threat of offshore winds combined with dry air and high temperatures have made 16 counties in the Sierra Foothills and the North Bay vulnerable to wildfires, the utility said on Tuesday. The company sent phone messages, texts and emails to those who might be affected by the shut-off, as a new fire in Southern California burned near multimillion-dollar homes.