The Wind Friction Effect
The final major factor affecting the direction that wind follows is friction. Near the surface of the Earth there a many things that interfere with wind, slowing it down, and changing its direction. These include trees, mountains, houses, buildings, lakes, oceans, and streams.
The effect of friction is only important near the surface of the Earth. The higher one travels into the atmosphere, the less obvious are the effects of friction. Above 5000 feet (1500 meters) winds almost always follow a geostrophic pattern, where they are balanced between the pressure gradient and the coriolis effect.