A Pacific storm sweeping through the northwest brought flood warnings Sunday in parts of several counties in western Washington and Oregon.

The National Weather Service said that heavy rains in the region likely would cause flooding through Monday, but there were no reports of serious problems in many affected areas Sunday morning.

Sheriff's departments in King, Lewis and Pierce counties in Washington all say they haven't had any calls about high waters.

Their counterparts in Clackamas and Tillamook counties in western Oregon also said the rains so far haven't disrupted activities for residents.

Forecasters warned that weekend storms may push some rivers and streams over their banks. Many waterways are already on the rise because of warming temperatures and melting snow.

The Oregon geology department said people living in or driving through steep areas should be wary of potential landslides and debris flows.

Oregon transportation officials on Sunday closed U.S. Highway 20, also called Santiam Highway, near Cascadia in central Oregon after a landslide brought about 150 cubic yards of mud, rock and debris into the road.

KOIN-TV reports that there's an increased danger of mudslides from Cottage Grove, Ore., northward well into Washington, mainly in the Coast Range and the western Cascades through Monday.

In Portland, a section of Southeast Powell Blvd., southeast of 82nd Ave. was partially under water Saturday, while a landslide forced the closure of the westbound lanes of Highway 26 in the mountains west of Hillsboro, KOIN reported.

KIRO-TV said the rains caused several rivers to rise, including the Snoqualmie River, while mudslides closed a few roads in Mason County and Pierce County.

Landslides closed sections of three southwest Washington highways, including State Route 14 near Cape Horn, State Route 411 near Hazel Dell Road in Kelso and State Route 508 at Bear Canyon.

A wind advisory was in effect Sunday afternoon for northern Idaho, the Palouse and southeast Washington. The weather service forecasted wind speeds between 15 to 30 mph with gusts up to 45 mph.

Drier and cooler weather to come Wednesday should help runoff, said Rocco Pelatti, a meteorologist with the National Weather Service in Spokane.