The National Weather Service is warning that on Wednesday, Northern California will face “a truly brutal” storm system that “needs to be taken seriously.”

The NWS said in its forecast that this “will likely be one of the most impactful systems on a widespread scale that this meteorologist has seen in a long while. The impacts will include widespread flooding, roads washing out, hillside collapsing, trees down [potentially full groves], widespread power outages, immediate disruption to commerce, and the worst of all, likely loss of human life.”

Over the weekend, a powerful storm hit Northern California, causing severe flooding in San Francisco. This new system is expected to bring moderate to heavy rain and strong winds to the Sacramento and San Francisco areas Wednesday through Friday, and Scott Rowe, an NWS meteorologist in Sacramento, told the Los Angeles Times that “everything is already wet and well saturated in many instances. It’s definitely a situation that we’re watching very carefully.”

The storm system is also going to bring rain to Southern California on Wednesday and Thursday, with NWS meteorologist David Sweet in Oxnard saying it’s looking “like it’s going to be the strongest of the season.” The main concerns are “damaging winds and flooding,” Sweet said, and winds of 50 mph could bring down “power lines, trees, tree branches.” It’s going to be “a challenging couple of days,” he added.