SEATTLE, Wash. — Two more atmospheric rivers are lined up to soak Washington and Oregon on Friday and Saturday, following two earlier storms this week that already dropped several inches of rain on both states.
The timing is rough for the coast. The storms are arriving during the yearly king tides, and federal forecasters warn that repeated atmospheric rivers can stack up into flash flooding, flooded city streets and landslides.
The National Weather Service in Seattle issued a coastal flood warning for San Juan County from 6 a.m. to noon Friday, with water 2.5 to 3 feet above ground possible along shorelines and many road closures expected. In Mason County, a flood watch runs through late Saturday night. Three to 4.5 inches of rain could fall on the south slopes of the Olympic Mountains, enough to push the Skokomish River near Potlatch over flood stage.
On the northern Oregon coast, the Portland forecast office has a high surf warning for Clatsop County from noon Friday to noon Saturday, with breakers of 30 to 35 feet, plus a coastal flood advisory Friday afternoon. Forecasters called the sneaker wave threat extreme and urged people to stay back from the surf and away from beach logs that waves can roll.
Atmospheric rivers are long, narrow plumes of water vapor carried by the wind, sometimes stretching 2,000 miles. Federal flood data shows they account for 90% or more of flood damage in the western United States.
Filed under: Washington DC Weather News
