Oregon’s first fall storm leaves Portland under siege of rain starting Tuesday, September 30, with commutes and roadways directly in the crosshairs. Drivers should expect slick pavement, standing water, and delays along I-5 and I-84 through Wednesday morning.
According to the National Weather Service, showers develop Monday night and strengthen Tuesday with an 80% chance of rain during the day, rising to 100% Tuesday night. Thunderstorms may flare, and wind gusts could top 20 mph across the Portland metro. Commuters are urged to slow down, allow extra time, and avoid flooded lanes.
The storm targets western Oregon with periods of heavy downpours, straining storm drains in Portland, Gresham, and Beaverton. Southbound I-5 traffic toward Salem faces the heaviest rainfall late Tuesday into early Wednesday. TriMet riders should prepare for service disruptions as road conditions deteriorate.
By Wednesday, showers persist with a 90% chance of rain. Forecasters warn this system sets the tone for early October, ushering in a wetter pattern that could linger into the weekend.
Residents should clear gutters, charge electronics, and secure outdoor items before conditions worsen. Storm drains blocked by falling leaves may quickly flood intersections and residential streets.
Advisories remain in place through Wednesday, and more alerts could be issued if thunderstorms intensify.
Five Day Forecast for Portland, OR:
- Monday: Rain likely, high 68°F. Showers continue into night.
- Tuesday: Showers, 80% chance, high 68°F. Heavy rain overnight.
- Wednesday: Showers, 90% chance, high 67°F. Thunder possible.
- Thursday: Showers likely, high 67°F.
- Friday: Chance of showers, partly sunny, high 67°F.
