Residents of the Pacific north-west are preparing for a round of heavy rain on Wednesday after an atmospheric river of moisture smacked the region a day earlier with rains that triggered mudslides and washed out roads and submerged vehicles.
In Washington, rain over the state’s watersheds and mountains are causing rising rivers that could imperil homes, livestock and lives in valleys from Mount Rainier to Mount Baker, the Seattle Times reported. Rivers, including the Carbon, Cedar, Elwha and Snohomish are forecast to rise close to record heights.
Farmer Ryan Lichttenegger told the outlet that his community outside Fall City, near the Snoqualmie River, is accustomed to floods but that this one feels unusual.
“I’ve seen many floods come and go, and I’ve never seen water come in and out of this barn like it has,” he said. “It’s really devastating to have a flooding event like this happen before Christmas time. We have lost quite a bit.”
Meteorologists said areas in the Cascade mountain range were receiving “impressive” rain rates near or exceeding a half-inch per hour.
“After a brief lull, rivers across western Washington are on the rise again this morning. Flows are rising very quickly, so travel with caution and NEVER drive into water flowing over the road,” the National Weather Service in Seattle posted on X.
Atmospheric rivers that are strong and slow-moving can produce heavy rain that can lead to flooding, especially along the west coast of the US in the winter season. This atmospheric river extends over 3,500 miles west into the Pacific Ocean, between Alaska’s Aleutian Islands and Hawaii.
Washington is experiencing a three-year drought, but the atmospheric river is forecast as an “AR5”, the top of the scale for strength and among the strongest and longest lasting in the region seen since 1959, Samuel Bartlett, a meteorologist with the Center for Western Weather and Water Extremes at UC San Diego’s Scripps Institution of Oceanography, told the outlet.
Rainfall from the storm could reach 2 to 4in across lower elevations and 10 inches higher up in the Cascades, alongside 45mph gusts of wind and temperatures up to the mid-50s F. The weather service forecast more than a foot of new snow in the northern Rockies in north-western Wyoming.
Since Monday, areas in the Washington and north-west Oregon Cascades, Olympics and coastal ranges have seen 5 to 10in of rain. Landslides in steeper terrain could be compounded by debris flows in areas recently burned by wildfires, NWS Seattle said.
On Tuesday evening, Washington governor Bob Ferguson said in a post on X that the state emergency operations center had been elevated to a level 1 due to the rain and wind.
“The center is in constant contact with local emergency managers and closely monitoring weather impacts. Our state emergency management personnel remain ready to support our local communities if they request help, and the Washington national guard has resources ready if necessary.”
Along Interstate 5 between Seattle and Portland, firefighters rescued five people who tried to drive on flooded roads, including a semit-ruck driver, said a spokesperson for Lewis county fire protection district 5.
Police said deputies went door to door in certain neighborhoods to warn residents of imminent flooding, and evacuated a mobile home park along the Snohomish River, northeast of Seattle.
With conditions set to worsen, Harrison Rademacher, a meteorologist with the weather service in Seattle, told the Associated Press that the atmospheric river soaking the region as “a jet stream of moisture” stretching across the Pacific Ocean “with the nozzle pushing right along the coast of Oregon and Washington”.
