why do most weather systems in the continental United States generally move from west to east (air in Earth's atmosphere)?

I dont understand this...

I know its due to temperature, convection, earth's magnetic field, but why and how does it exactly all happen?

why do most weather systems in the continental United States generally move from west to east (air in Earth's atmosphere)?

I dont understand this...

I know its due to temperature, convection, earth's magnetic field, but why and how does it exactly all happen?

First of all, the magnetic field plays no part in the weather. It's driven entirely by heat.

Looking at only the area you're speaking of, it's not difficult to describe. The warm air rises from the tropics, decends at the pole and begins to flow southward back toward the equator. It's otherwise direct flow is deflected to the east by the topography - mountain ranges like the Rockies and others - AND by the jet stream. The final direction is not so much west to east as it is northwest to southeast. However, it's often deflected more eastward by warm masses moving north from the Gulf region.

Have to add in the Coriolis effect which causes the Polar Easterlies in the Winter, and also the effects of the jet stream above the traposphere. Also diferences between low and high pressure zones.

El Nino cycles about every 7 years or less. It's normally an easterly but then reverses (La Nina) to become a westerly. If strong enough, this often effects the Southwestern U.S. The reason for its reversal are not clearly understood but are thought to also involve thermal reverse circulations in the Pacific Ocean.

Also, sometimes we get westerly winds coming across Texas, New Mexico, and Arizona from the Gulf of Mexico. I don't know why.

I stated the above slightly backwards because I meant "easterlies" when I said "westerlies." Westerlies are winds that come from the West, but sometimes there's a reversal - as with La Nina - and sometimes we get easterlies coming across the Gulf from the East that then move upwards towards the Northwest. Polar Easterlies are felt nearer to the North Pole.

In any case, the answer to your question is due to the Coriolis Effect at the equator, which is caused by the Earth's spin. Air is deflected by the Coriolis force at the equator: clockwise above the equator creating prevailing westerlies (west to east), and counterclockwise below the equator. In the mid-latitude regions, such as where the U.S. is, this generally still produces westerlies, but it varies because of the mid-latitude circulation areas. Also, in addition to this, if a low pressure area forms somewhere, then winds will be directed towards it and deflected accordingly in different directions: again, this is due to the Coriolis effect and thermal gradients.

Look at all the southeasterly winds that bring in hurricanes along the Atlantic coast (southeast to northwest). But in general, the winds that come in from the Pacific are from the West. In the winter, in northern parts of the United States, arctic winds flow down from the North in a southeast direction.