No flooding expected as PNW rivers swell with snowmelt

PORTLAND, Ore. (KOIN) — With temperatures rising into the mid 40s in the Northern Cascades and Coast Range Monday, melting snowpack is forecast to increase river and stream flows in Northwest Oregon and Southwest Washington this week, skirting flood levels in some areas.

The most-affected areas are expected to be in the drainage basins of the Coast Range and the Willapa Hills. Data provided by the National Weather Service shows that the local rivers forecast to see the most dramatic water level rise includes the Tualatin River near Dilley, the Luckiamute River near Suver, the Grays River near Rosburg, the Wilson River near Tillamook, the South Yamhill River near McMinnville and the Pudding River near Aurora.

Local rivers swelling with snowmelt

The NWS stated in a hazardous weather alert Monday that none of these rivers are expected to reach the flood stage, although some are expected to come within inches of minor flood conditions. The heightened water levels are expected to peak between Tuesday and Wednesday.

“Overall, widespread river flooding is not expected with this event, but the chance of minor flooding is just high enough to warrant [an advisory],” the NWS stated. 

As much as two inches of rain is also expected to fall across the region early this week, creating potentially hazardous driving conditions, the NWS warns. Pooling water on roadways will be possible, significantly increasing the risk of hydroplaning.

Drivers are advised to slow down during these damp conditions.