The flood threat is growing across portions of Washington and northern Oregon as an atmospheric river brings heavy rain and mountain snow to the region.

A prolonged atmospheric river will continue to bring the threat of flooding through the end of the week across portions of the Pacific Northwest. A narrow, but intense, plume of moisture originating from Hawaii is surging through the region. This comes after two days of steady rainfall for parts of Washington and Oregon.

Widespread urban and river flooding is expected, with considerable impacts along the Skagit and Snohomish Rivers. Flooding is also expected from the foothills of the Cascades to Puget Sound. Seattle, Tacoma and Olympia, Wash., are at risk today. The risk of flooding also stretches into northern Idaho and western Montana.

Widespread rain totals of 2-3 inches are expected through the end of the week, with some spots picking up 5 inches or more locally. Snowmelt may also contribute to flooding today into the end of the week. Areas of steep terrain will remain at risk for landslides. While the rain will start to taper off by Friday, rising rivers will remain an issue even after the rain ends.