Breakdown: Why weather systems move from west to east

MEMPHIS, TN (WMC) - In the United States, most of our weather moves from west to east but in actuality systems can move in any direction. You may notice that we are always looking west to see what’s coming next.

The reason that they most often move from west to east is due to the jet stream. The jet stream is a narrow band of fast, flowing air currents located near the altitude of the tropopause that flow from west to east. The jet stream flows around the entire earth. They usually have a meandering, snake-like shape.

Jet streams carry weather systems. Warmer tropical air blows toward the colder northern air. These winds shift west to east due to the rotation of the earth.

Every once in awhile, we get a backdoor cold front in the Mid-south. This is because an area of low pressure can pull down a cold front from the northeast to the southwest.

The structure of low pressure systems, which move cold fronts, favors a front moving either north to south or northwest to southeast. Warm fronts generally move from south to north on the east side of the low pressure system’s counter-clockwise circulation, making an east to west motion more unusual. The systems that move east to west are tropical systems due to the easterly trade winds.

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