Weather patterns move from west to east due to the jet stream, which is a fast flowing air current found at an altitude of about 9 1/2 miles above the Earth's surface. This phenomenon occurs due to factors, such as the Earth's rotation and the difference in temperature between two air masses.
The formation of jet stream winds occur due to two air masses that have very different temperatures, such as the colder air masses of the North Pole region and warmer air masses near the equator in the south. The warm tropic region is associated with high pressure, which tends to move towards the low pressure at the North Pole. However, because to the Earth's rotation, the jet stream is deflected such that it moves from west to east.