The Columbia River was measured at 15.96 feet shortly after 8:30 a.m. Thursday, according to the National Weather Service. Minor flood stage is 16 feet.
The river was expected to rise above flood stage at about 10 a.m. and likely crest at about 16.1 feet around noon and gradually fall throughout the weekend.
Parks and trails along the river, as well as some islands, will likely have some flooding, the weather service said.
The Weather Service warned boaters to be cautious of faster currents and more debris in the water.
The National Weather Service issued a flood warning for the area from Thursday morning to 10 p.m. Friday.