National Weather Service (NWS) meteorologists are warning that an atmospheric river event is poised to soon deliver storms to the Pacific Northwest.
“We’ve had systems that have characteristics of atmospheric rivers, but this one and potentially some after, it’ll be an active pattern, will have the true qualities of an atmospheric river,” NWS meteorologist Joshua Wood told Newsweek.
Why It Matters
Atmospheric rivers are a “long, narrow region in the atmosphere—like rivers in the sky—that transport most of the water vapor outside of the tropics,” according to the National Oceanic and Atmospheric Administration.
The storms brought by atmospheric rivers are known for their heavy snow, heavy rain and strong winds. They more commonly affect the West Coast, particularly during the winter months. Although the storms can bring beneficial snow that helps supplement reservoirs throughout the summer dry season, they can also trigger deadly flooding, mudslides and widespread power outages.
What To Know
NWS meteorologists at the Climate Prediction Center (CPC) began tracking the atmospheric river earlier this week, anticipating the storm will impact the Pacific Northwest from October 24 to October 27.
Oregon’s southern coast and Northern California are at the greatest chance for heavy rainfall from the storm, but there’s a moderate chance that they will impact a wider swath of the Pacific Northwest, extending from Northern California through western Oregon and Washington.
Other weather threats include high winds across those same areas. Some parts of Northern California and southern Oregon could also see heavy snow, which could fall across parts of Montana, Wyoming and Idaho.
“Travel may be impacted by heavy snow, rain, and wind,” said a key message from the NWS CPC. “Heavy rain will also have the potential to produce small stream and urban flooding, though confidence is not high at this point. Interests should continue to monitor forecasts.”
The NWS CPC precipitation outlook from October 22 to October 26 shows a high chance of above average precipitation for the Pacific Northwest that coincides with the incoming atmospheric river threat.
What People Are Saying
Extreme weather chaser Colin McCarthy, in a post on X Thursday: “A Pacific jet extension will roar across the Pacific in late October, bringing the potential for a strong atmospheric river in the Pacific Northwest and possibly Northern California. Heavy mountain snow is possible as far south as the Sierra Nevada. Stay tuned.”
NWS, in a post on X Wednesday: “An atmospheric river event favors increased chances of stormy weather over the Western U.S. during late October.”
What Happens Next
Those living in the Pacific Northwest should monitor the forecast as the storm gets closer. Should the storm hit, the NWS will issue any weather alerts or warnings necessary to update the public on conditions.