The Portland office of the National Weather Service issued a Flood Watch for much of the region early Friday morning.
According to the federal weather agency, flooding, caused by excessive rainfall over the weekend and through Tuesday afternoon is possible.
“Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations,” the NWS said in the Flood Watch. “Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas.”
The Flood Watch, in effect from 5:29 a.m. Friday through Tuesday afternoon could be followed by the more immediate Flood Warning, according to the NWS.
“A Flood Watch is issued when conditions are favorable for flooding. It does not mean flooding will occur, but it is possible,” the agency said on their website, compared to a Flood Warning, which is issued when flooding is already happening or about to.
The area the watch was issued covers much of northwest Oregon and portions of southwest Washington, including the Northern Coast Range, the Portland Metro area, the North Coast and the Central Coast, much of the Willamette Valley and the Cascade foothills, among other areas.
The Oregon Coast Range could see between 4 and 1/2 to 6 and 1/2 inches of rain, while the valley could see between 3 and 4 inches of rain.
The NWS warned that river levels could rise quickly.
“Most rivers have anywhere from a 30-50% chance of reaching at least minor flood stage,” the NWS said, with the exception of the mainstem Willamette and Columbia Rivers, which have a less than 10% chance.
Coastal rivers have a 40-60% chance of reaching minor flood stage and 20-30% chance for reaching major.
Sand and sandbags can be found in Banks in the parking lot of Sunset Park.