Pacific Northwest faces "catastrophic" flood threats
Add Axios as your preferred source to
see more of our stories on Google.
A vehicle drives through flood waters from the Snohomish River in Snohomish, Washington, on Dec. 11. Photo: Jason Redmond/AFP via Getty Images
Residents in the Pacific Northwest face "catastrophic" and potentially life-threatening flood threats after days of heavy rains, the National Weather Service warns.
The big picture: Washington's governor declared a statewide emergency Wednesday to respond to the flooding that's already prompted water rescues, closed roads, caused power outages and left tens of thousands under evacuation orders in the state and across the border in the Canadian province of British Columbia.
- Northwest Oregon also faces flooding and landslide threats from this week's atmospheric river event that produced 5 to 10-plus inches of rain, per an NWS forecast update Thursday.
- Precipitation from the intense rainfall that began earlier this week was diminishing Thursday across the Pacific Northwest following the end of the atmospheric river, a narrow current of moisture-laden air that can transport vast amounts of water vapor thousands of miles.
Yes, but: "While drier weather looks to be in store for this area of the country through the upcoming weekend, the major to catastrophic flooding effects are likely to continue for several days across portions of western Washington State and northwestern Oregon," the NWS said.
- The extreme weather has already caused rivers in Washington to reach record levels.
State of play: About 100,000 people in Washington were expected to evacuate from rising floodwaters, with the worst-hit communities living near the Snohomish and Skagit rivers in the state's west.
- Flooding has closed multiple roads in the state and across the border in Oregon, where the NWS warned rivers were expected to rise near coastal communities.
- "Catastrophic river flooding impacts," especially along these two rivers will continue through Friday and "bring a significant risk to life and property" in Washington, the National Water Center warned on X. "There is a high risk of levees being topped."
Zoom in: Washington Gov. Bob Ferguson, who's asked the federal government to expedite an emergency declaration for his state, wrote on X the Skagit River will be cresting mid-morning Friday, and that's "expected to be at a historic level."
- While Seattle had mostly avoided the flooding, landslides, road closures and evacuations that had impacted elsewhere in Washington and B.C., Amtrak's train service between the city and Vancouver was suspended through Friday.
- However, the main highway between Seattle and Vancouver remained open.
Zoom out: In Canada, the B.C. Ministry of Transport said five of the six roads into and out of Vancouver were closed due to flooding rains, fallen rock and debris, and high avalanche hazards.
- "This situation is evolving and very dynamic," per the department's statement.
Between the lines: Climate change is adding even more moisture to atmospheric rivers, enabling them to dump higher totals of rain and snow, studies show.
- Research has also found that rainstorms are getting more intense in many U.S. cities due to climate change.
Zoom in: The fact that "parts of Washington are seeing record-breaking flooding this week is not surprising," given that many locations saw record 24-hour precipitation that's been well above the 100-year average recurrence interval (ARI) — a rainfall event that is expected to occur on average once every 100 years, per Daniel Swain, a climate scientist at the University of California Agriculture and Natural Resources.
- Another factor was "near-record temperatures" and no snow in on the mountains, so all the precipitation became runoff, Swain wrote on Bluesky.
In photos: Washington slammed by flooding rains
Go deeper: Why Seattle didn't get slammed with rain
Editor's note: This article has been updated with additional details throughout.
