Despite the same latitude, the climate is different in the east. Also notice that it's not really the whole east - more like central US. This area is called Tornado Alley. Basically, cold and dry air from Canada meets warm and moist tropical air from the Gulf of Mexico, thus giving perfect conditions to form tornadoes. Because western US lies above Mexico and the wind there goes over a large land mass, the air is different than from the water mass of the Gulf.

In Florida there are many tornadoes as well but this time because it is a magnet to thunderstorms.

And then there is West Virginia. The unique climate of this state is not good for tornadoes. Some people (just look at previous threads with the same pictures on Reddit) claim that it's the Appalachian Mountains that stop tornadoes from occurring in West Virginia, but it's just a common misconception. Sure, mountains contribute to the special climate, but they aren't sole reason for reduced number of tornadoes.