Atmospheric River Unleashes Historic Floods Across Washington: What’s Fueling the Deluge?

In the second week of December 2025, the Pacific Northwest found itself at the mercy of a weather phenomenon both awe-inspiring and alarming: an atmospheric river. This vast plume of moisture, sometimes called a “Pineapple Express,” has been responsible for some of the region’s most memorable storms. But this time, the deluge brought a cocktail of chaos—record-shattering floods, frantic rescues, and a stark reminder that even too much water can’t wash away the threat of drought.

As torrential rain battered Washington and Oregon, rivers surged toward historic highs. In Skagit County, officials braced for what they called “historic flooding,” warning that the Skagit River could surpass its all-time record crest by more than five feet. The National Weather Service sounded alarms across western Washington: nearly 6 million people faced major-to-record, life-threatening floods. Communities from the Cascade Foothills to Puget Sound watched the water rise and wondered if their levees—and their luck—would hold.

Evacuations, Rescues, and the Human Toll

For residents like Jenni Geel in North Bend, the atmospheric river was no abstract meteorological concept—it was the cold water creeping up her basement stairs. With three of her children’s bedrooms under three feet of water, Geel packed up what she could and prepared to move her family to safer ground. “Now it’s just kind of like sit and wait and see if the levee can hold,” she told CNN. Her story echoed across the region, as dozens of communities issued evacuation orders or warnings, urging people to leave ahead of the rising tide.

In Orting, water rescue teams in rafts braved swift currents to save people stranded at an RV park. In Snohomish County, the Everett Animal Shelter called for emergency foster homes as floodwaters threatened its kennels. Across the region, drone footage revealed homes and streets swallowed by muddy rivers, and first responders worked around the clock to shepherd residents to safety.

Mount Vernon Mayor Peter Donovan described his city’s predicament as a “worst-case scenario.” The Skagit River, usually a scenic backdrop, was now a threat that could put 9,000 residents in harm’s way. Flood stages were being surpassed by several feet; the Snohomish River near Monroe, for example, was forecast to crest nearly five feet higher than its previous record. The impacts were widespread—Amtrak suspended service between Seattle and Vancouver, and major highways were washed out or closed due to water on the roads.

What Is an Atmospheric River—and Why Are They Getting Worse?

Atmospheric rivers are not a new phenomenon in the Pacific Northwest, but their power and frequency have captured public attention in recent years. Scientists describe them as “fire hoses” in the sky—narrow bands of concentrated moisture pulled from the subtropics and unleashed as intense rain when they hit land. This week’s event, classified as an “AR5” (the highest category), ranked among the top 1-2% strongest and longest-lasting since 1959, according to the Center for Western Weather and Water Extremes at UC San Diego’s Scripps Institution of Oceanography (Seattle Times).

What’s changed? Climate scientists point to a warming atmosphere and ocean. For every degree Fahrenheit of warming, the atmosphere can hold 4% more moisture—fuel for heavier downpours. Ocean temperatures off Washington and Oregon are about a degree warmer than normal, and the air mass arriving with this atmospheric river is up to 25 degrees warmer than usual for December. These conditions, made more likely by climate change, are supercharging storms and making record floods more common.

“A little bit like a fire hose,” said Washington State Climatologist Guillaume Mauger. “Most (but not all) of our big storms here come from atmospheric rivers. This particular one is large, but it’s probably not a record-setter.” Still, the impacts are unmistakable: rivers flowing at rates the U.S. Geological Survey calls “extremely above” normal, and floodwaters stranding people and animals alike.

Floods Amid Drought: A Paradox in the Pacific Northwest

Here’s the cruel irony: as the region drowns in floodwater, it’s still locked in drought. After three consecutive years of severe dryness, Washington’s reservoirs are running low and vast areas remain classified as “abnormally dry” or worse by the U.S. Drought Monitor. The current atmospheric river is dumping 2 to 4 inches of rain at low elevations and up to 10 inches in the Cascades, but experts warn this won’t erase the water deficit.

The problem is twofold. First, much of the rain is falling too fast to be absorbed or stored; it rushes through rivers and out to sea before reservoirs can capture it. Second, warmer air means more precipitation is falling as rain instead of snow, especially at lower elevations. That’s a missed opportunity: snowpack acts as the region’s natural reservoir, slowly releasing water through spring and summer. “What this state needs now more than rain,” said Caroline Mellor, drought coordinator at the Department of Ecology, “is snowfall. But temperatures aren’t cold enough to freeze the precipitation across the lower elevations.”

Unless the trend reverses and snowpack rebounds, the Pacific Northwest could face yet another year of drought—even as its rivers overflow.

Emergency Response, Community Resilience, and the Road Ahead

In response to the unfolding crisis, Washington Governor Bob Ferguson signed an emergency proclamation, activated the National Guard, and requested federal assistance. “Rising rivers and ongoing flooding across the state have led to evacuation orders,” Ferguson said. “This allows us to seek federal funds to cover the costs of this response, which we anticipate will be significant.”

Local officials and scientists are also mobilizing. The Center for Western Weather and Water Extremes is launching weather balloons and coordinating research flights to gather critical data for future forecasts. Their aim: to improve early warning systems and help communities prepare for what may be a new normal.

For now, the people of Washington and Oregon are left to clean up, rebuild, and—perhaps most crucially—rethink how they manage water in an era of extremes. The atmospheric river has made one thing clear: the Pacific Northwest’s relationship with water, whether in scarcity or abundance, is being rewritten by forces both natural and human-made.

Assessment: The 2025 atmospheric river event is a microcosm of the climate paradox gripping the Pacific Northwest—where historic floods and persistent drought collide. While emergency responses have limited immediate harm, the underlying causes—warmer air and ocean temperatures, shifting precipitation patterns—underscore a deeper vulnerability. The region’s challenge now is to adapt its water management and infrastructure, recognizing that both too little and too much water are the new norm in a changing climate.