Portland, OR. — The National Weather Service (NWS) has issued a Flood Watch for all of Northwest Oregon, effective from late Wednesday night, December 17, through late Friday night, December 19, 2025, as a strong atmospheric river is forecast to bring heavy rainfall to the region.
Forecasters warn that the prolonged rain may result in flooding, landslides, and debris flows, particularly in areas of steep terrain and in or near burn scars from recent wildfires. Debris flows are a specific concern, as they can develop rapidly and travel long distances with little warning.
According to the NWS, debris flows are extremely destructive landslides composed of fast-moving soil, water, rocks, and logs. These flows can move faster than a person can run and may travel a mile or more down steep slopes, through narrow canyons, and into low-lying areas. Homes, roads, and other infrastructure located below steep hillsides or near canyon mouths are considered especially vulnerable.
Residents and travelers in the watch area are urged to remain alert and monitor weather updates through radio, television, weather radio, or online sources. Officials advise immediate evacuation if ordered. Warning signs of potential debris flows include unusual sounds such as cracking trees or rocks colliding, trickles of mud or debris, or sudden changes in the color or flow of nearby streams and creeks.
Drivers are advised to use extreme caution, particularly at night, as road conditions may deteriorate quickly. Embankments along roadways can fail without warning, depositing rocks and debris onto travel lanes.
The National Weather Service emphasized that conditions may change rapidly as the storm system develops and encouraged residents to stay informed throughout the watch period.
Additional information and updates are available from the National Weather Service at weather.gov, and landslide and debris flow preparedness resources can be found through the Oregon Department of Geology and Mineral Industries.
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