Prevailing winds are major wind patterns that cover large geographical areas

In Ontario the prevailing wind direction is from the West

Prevailing winds help to distribute large amounts of solar energy and moisture from the equator to colder parts of the planet (advection)

Because the sun hits most directly around the equator, air rises in this area and forms the equatorial convection current

Rising air sucks in air from both north and south which creates wind at the surface

If the earth were flat and did not move the winds would flow from S to N and N to S in one continuous circulation cell

                                                                   

The atmosphere of the earth rotates along with the earth at about 300m/s

Different points on earth move at different speeds

When air begins to move N or S due to convection it continues to move east at the same speed it was moving before it changed latitude

This means that fast air moving north will appear to be to curve to the right (east) creating a prevailing west wind

The influence of earth’s rotation on air or on any object moving on the earth’s surface is called the Coriolis effect

Depending on the direction of convection/advection different prevailing winds are set in motion

The Jet stream(s) are ribbons of extremely fast moving air near the top of the troposphere.

They are caused by convergence between cold and warm air creating a large pressure differential

Therefore Jet streams only occur between circulation cells