National Weather Service:
The Flood Watch is now in effect for portions of Northwest Oregon and Southwest Washington, including the following areas, in Northwest Oregon, Central Coast Range of Western Oregon, Central Oregon Coast, Central Willamette Valley, Coast Range of Northwest Oregon, Greater Portland Metro Area, Lower Columbia, North Oregon Coast, Northern Oregon Cascade Foothills, and Upper Hood River Valley. In Southwest Washington, Central Columbia River Gorge, Greater Vancouver Area, I-5 Corridor in Cowlitz County, South Washington Cascade Foothills, South Washington Coast, Western Columbia River Gorge, and Willapa Hills.
The Flood Watch will continue through tomorrow afternoon.
A long period of moderate rain with embedded periods of heavy rain that started Monday afternoon and lasting through this morning will result in sharp rises on many rivers and creeks across Northwest Oregon and Southwest Washington. Minor flooding is possible.
In addition to river and creek flooding, widespread urban flooding is possible in the Northern Willamette Valley and Portland Metro Area. In these areas, there may be water entering underground portions of buildings and parking garages as well as multiple feet of water in flood-prone paved areas such as low or dipping freeway ramps.
Rainfall totals of 2.5 to 5 inches are expected for the coast,with 3 to 8 inches in the Willapa Hills, Coast Range, Cascades,and Cascade foothills. Meanwhile, 1.5 to 3 inches of rain are expected across the inland valleys.
* Rivers of particular concern include the Grays River in Wahkiakum County, the Wilson River in Tillamook County, the Siletz River in Lincoln County, the Upper Tualatin River in Washington County, the Clackamas River in Clackamas County, and Johnson Creek in Multnomah and Clackamas counties, and the Luckiamute River in Benton and Polk counties.