Oregon Public Broadcasting

Heavy rains have forced the Portland Rose Festival to temporarily shut down Waterfront Village.

And the National Weather Service is warning people in the Coast range and Cascade mountains there could be landslides this week. Amelia Templeton reports.

The jet stream is aiming a plume of tropical moisture from the Philippines right at Oregon and Washington. The storm should let up briefly and then continue Friday.

Geologists say this late in the year the ground is already saturated. So the rain could trigger large landslides called debris flows in valleys and streambeds. 

Bill Burns is with the Oregon Department of Geology. Bill Burns: "These debris flows can move tens of miles per hour if not fifty miles an hour. And that is hard to get out of the way. You can’t run that fast."

Burns says the debris flows can travel for miles and tend to get larger and more dangerous as they move.

Oregon and Washington residents should avoid the mouths of valleys and exposed slopes.