Western parts of the Pacific Northwestare facing flooding after an atmospheric river moved over the region.

On Tuesday, Dec. 9, Washington and Oregon saw heavy rain that impacted local waterways, according to the National Weather Service in Seattle. Areas in Washington experienced at least half an inch of rain per hour.

Paradise, Washington, located on the south slope of Mount Rainier National Park, around 103 miles southeast of Seattle, received 3.25 inches of rain in the last 10 hours.

The flooding was caused by an atmospheric river. These systems, which are often called a "Pineapple Express," are a "long, narrow region in the atmosphere – like rivers in the sky – that transports most of the water vapor outside of the tropics," according to the National Oceanic and Atmospheric Administration.

The flooding was brought on after two atmospheric rivers moved over the region back-to-back, according to AccuWeather

The Pacific Northwest region includes Oregon, Washington, Idaho and British Columbia, Canada. Oregon and Washington were the states primarily affected on Dec. 9.

Significant river flooding is expected to continue throughout the week, but drier conditions are possible during the weekend, according to the NWS.

Photos show the aftermath of the torrential downpour, including cars submerged halfway in flood waters and residents using boats to navigate flooded areas.

See photos of the flooding in Washington, Oregon

Julia is a Trending reporter for USA TODAY and covers scientific studies and trending news. Connect with her on LinkedIn, X, Instagram, and TikTok: @juliamariegz, or email her at jgomez@gannett.com

This article originally appeared on USA TODAY: Photos show atmospheric river bringing flooding to Pacific Northwest

Reporting by Julia Gomez, USA TODAY / USA TODAY

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