Why do winds in the tropics tend to move east to west?

This is due to two factors: Air in the tropics generally moves in the direction of the equator. Moving air is deflected by the rotation of the Earth. In the northern hemisphere, the deflection is to the right (seen with the wind in the back) and in southern hemisphere, it is to the left. read more

Weather can move in any direction from regions of high pressure toward regions of lower pressure. In the northern hemisphere, weather moves west to east due to the warmer, higher pressure tropical air blowing toward colder northern continental air, and these winds shift west to east due to the rotation of the earth. In a nutshell. read more