Why Does Weather Move West-To-East?

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By By Steve Pool

SEATTLE - You might think since the Earth rotates toward the east, that our weather would come from the east as we "run into" it. But no, our atmosphere is spinning along with us at nearly the same speed near the ground.

Instead, weather moves west-to-east thanks to the jet stream, which is a high-altitude wind that moves west-to-east and generally steers our weather.

It’s caused from the temperature difference between our warm equator and cold poles. High pressure at the warm tropics wants to flow toward the low pressure at the cold poles, but the Earth's spin deflects these winds to the east so that they make a circle around the globe (in both hemispheres) moving west to east at mid-latitudes.

The jet will dip to the north and south as individual low and high pressure systems form, but always carries our weather east.

Your Photos

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These images were taken Sunday, December 14 with a Nikon D3100 and an Explore Scientific ED127 (Moon) and ED80 (M42
and M31).
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The images of M42 (Orion) and M31 (Andromeda) are short
stacks (lights only) taken Sunday evening with an Explore
Scientific ED80 (wide angle) telescope and a Nikon D3100 DSLR. The image of the moon was taken with an Explore Scientific ED127 (5-inch) refractor.