Another atmospheric river will bring more rain to the Pacific Northwest later this week, heightening an extensive flood threat.

What is it about mid-December weather? The latest atmospheric river has brought warm, heavy rain, resulting in widespread major flooding and landslides.

Powerful wind gusts knocked out power to more than 500,000 customers across Washington and Oregon early Wednesday, as the latest atmospheric river intensified over the flood-devastated region. The Skagit River forecast indicates it will rise back into major flood stage early Wednesday.

The Washington State Department of Transportation (WSDOT) says crews have reopened more than 50 highways as western Washington is still recovering from an atmospheric river that caused historic flooding.

(THE CONVERSATION) Along the U.S. West Coast, atmospheric rivers are dreaded for the damage they can cause, but they are also essential to the region’s snowpack and water supply, as Qian Cao, a hydrologist at the University of California, San Diego, explains.

As another atmospheric river moves over Washington, it is expected that the area will receive another 5-8 inches of rain. This comes just days after a historic flooding devastated parts of Washington.

Starting tonight, an atmospheric river takes aim at northwest Oregon. Heavy rain and strong winds are back in the forecast.

Portland’s latest atmospheric river sent wind and rain into western Oregon and Washington overnight. Scattered showers will continue as the winds begin to calm.