From which direction does most bad weather arrive

Most bad weather arrive from the West.

Weather most often moves from west to east in the United States because that is the direction the jet streams blows. The jet streams are narrow bands of strong wind in the upper levels of the atmosphere. It carries weather systems along with it.

Tropical climate is experienced in the nothern countries of south america

Magma forms by partial melting of upper mantle and crust. partial melt means that only a fraction of the available material forms a melt, and that the remainder stays solid. the partial melt rises because of its lower density and ascends through he crust. this is so conclusive mean the answer would be magma igneous rocks or balistic magma.