West Coast Braces for Powerful ‘Atmospheric River’ Storm

The Pacific Northwest and Northern California are preparing for a major storm that’s expected to bring much-needed rain and snow, but also the potential for significant flooding, Bloomberg reports.

This powerful weather system, known as an “atmospheric river,” is set to unleash heavy precipitation across the region starting Thursday and lasting through the weekend and into next week.

Forecasters at the US Weather Prediction Center anticipate up to 7 inches of rain in some areas, with the mountains of the Cascade and Sierra Nevada ranges potentially seeing over a foot of snow. The storm’s arrival is a stark contrast to the recent dry, windy conditions that fueled devastating wildfires in Southern California, resulting in tragic loss of life and widespread destruction.

Atmospheric rivers are essentially concentrated channels of moisture that can transport enormous amounts of water vapor, comparable to the flow of the Mississippi River. This upcoming system is predicted to bring both benefits and risks to different areas.

While Oregon, Washington, and parts of California are expected to experience the storm at levels 1 and 2 on a scale developed by the Scripps Institution of Oceanography (considered beneficial for water supply), the San Francisco Bay area faces the possibility of hitting levels 3 and 4. These higher categories are considered destructive and raise the concern for significant flooding and related hazards.