Climate change fuels historic washington state flooding as atmospheric rivers unleash torrential rains

Washington State is grappling with potentially historic flooding after a series of powerful atmospheric rivers—moisture-laden storms stretching from the subtropical Pacific—dumped up to 18 inches of rain across the region in recent weeks. Governor Bob Ferguson declared a state of emergency and issued evacuation orders for 100,000 residents as rivers burst their banks, forcing 250 water rescues and closing 30 major roads.

Climate change has created a perfect storm of conditions that supercharged these flooding events. Warmer ocean temperatures allowed the atmospheric rivers to carry more moisture, while unusually warm air temperatures prevented snow from forming in mountain ranges. Instead of being absorbed by snowpack, the heavy rains rushed directly into rivers and streams. Areas still scarred by recent wildfires, like the 2022 Bolt Creek Fire zone, became particularly vulnerable as burned soil and debris created additional flood risks and blocked escape routes.

The flooding exemplifies how climate change is reshaping weather patterns across the West. Scientists note that atmospheric rivers have become wetter, larger, and more frequent since 1980, consistent with a warming atmosphere’s ability to hold more moisture. Adding to the crisis, much of the western U.S. had been experiencing drought conditions for months before these storms hit, meaning the parched landscape couldn’t absorb the sudden deluge.

As additional storms continue battering the region with forecasts of another 8 inches of rain, Washington may paradoxically end the year with near-normal rainfall totals—but concentrated into just a few catastrophic events rather than spread throughout the year, creating far more dangerous conditions for communities.