(Adds Oregon governor declares emergency)
By Eric M. Johnson
SEATTLE, Dec 10 (Reuters) - Fresh storms hit the U.S. Pacific Northwest on Thursday, triggering a state of emergency in several counties, after it received record-breaking rainfall that left two dead in Oregon and triggered widespread flooding, landslides and power cuts.
Periods of heavy rain and fierce winds will continue across the region and down into northern California as the next installment of storms moves onshore, and warnings of coastal floods were issued for 3 a.m. to 9 a.m. local time on Friday morning (1100 to 1700 GMT), the National Weather Service said.
Oregon Governor Kate Brown declared a state of emergency for 13 counties.
"Heavy rains and wind have required the evacuation of residences and mudslides and high water have severely damaged or blocked major roadways in these areas of the state," she said in a statement.
Meteorologists said the El Nino weather phenomenon, which can trigger above average precipitation in areas like the Pacific Northwest, is expected to remain strong through this winter.
"We still have rivers over flood stage in 11 counties as of 6 a.m. (local) but most of the rivers have crested and are falling," said Washington Military Department spokesman Mark Stewart. Rainfall was expected for Friday and Saturday, he said.
The storms this week, which shattered at least five weather records for the Seattle area including the wettest first nine days in December, triggered mudslides and flooding, closed roadways and schools and prompted Washington Governor Jay Inslee to declare a state of emergency.
In a rare event for the Pacific Northwest, the National Weather Service on Thursday said it received reports of a moderate-strength tornado in Battle Ground, Washington.
In Oregon, a 60-year-old Portland woman died in bed this week when a tree fell on her house and another woman drowned when her car became submerged in standing high water in the state's north, officials said.
Power outages affected thousands of residents in various parts of the region with a principal utility in Portland, the largest city in Oregon, reporting 2,250 without power on Thursday evening.
Schools in a number of districts were closed on Thursday.
In Kalama, along the Columbia River in southern Washington, flooding prompted evacuations of businesses and homes and a pool of sewage-tainted water formed over several blocks and began seeping into the police station and other buildings, Stewart said. (Reporting by Eric M. Johnson in Seattle; Additional reporting by Courtney Sherwood in Portland, Oregon, Rory Carroll in San Francisco and Alex Dobuzinskis in Los Angeles; Editing by Andrew Hay and Nick Macfie)
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