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Rivers of the atmosphere…we’re not talking the Mississippi or Missouri

Here in mid-Missouri we’re pretty familiar with rivers and the way they impact the land around them. But what are atmospheric rivers and how do they impact the surface of the Earth?

In the Pacific Northwest they’ve been dealing with a ton of rainfall... In fact nearly record setting rainfall in the last two weeks alone.All of this moisture is stemming from an atmospheric river that has settled over the area.

The Pacific Northwest has seen several inches of rainfall in the past week and its expecting more

We all are familiar with the concept of how upper level winds impact our weather systems by bringing moisture and different air masses to new locations. In this case, you can see that the upper atmosphere winds are travelling almost directly on top of the Pacific Northwest.

Upper level winds are centered over the PNW
Things will briefly calm down, but winds will still be in the area
Strong winds return for next week

When we take a look at where moisture in the atmosphere is located, you can see that the winds are dragging the moisture off the western coast of the United States inland almost directly over the Pacific Northwest as well.

Moisture is pulled in from the west toward land

This has brought significant rainfall to the area in the last few days... nearly 6.5” inches of it since the new year started! Flooding concerns are rising as this atmospheric river doesn’t appear to move out of the region for the next few days at least. This upper atmospheric pattern of when winds bring loads of moisture to a region has been dubbed the creation of an atmospheric river.

Flood watches and warnings are in effect for many parts of the PNW

To put the size and magnitude of this atmospheric river into perspective, the Missouri River stretches nearly 2,300 miles. This atmospheric river in the Pacific Northwest stretches more than 2,700 miles. Luckily for us, these atmospheric rivers tend to be situated along coastlines, not over the Midwest. There is room for debate as to whether systems that impact the Midwest and share similarities with atmospheric rivers should be labeled as such.

Insider Blog / Video / Weather / Weather Video
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Maddie Est

Maddie Est appears on ABC 17’s weekend evening broadcasts. She grew up in St. Louis, and her passion for weather originated from a young age thanks to all the different weather that St. Louis receives. She is currently studying Atmospheric Science at the University of Missouri.


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