Pacific Gas & Electric warned that it would likely cut power temporarily to hundreds of thousands of customers in Northern California by Wednesday night for the second time 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 Monday. 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.

The sole purpose of the shut-off “is to significantly reduce catastrophic wildfire risk to our customers and communities,” said Michael Lewis, PG&E’s senior vice president for electric operations, who made the decision to cut power to about two million people two weeks ago.